Impact of clomipramine prenatal exposure on sexual behavior and reproductive organs in female rats: role of sexual experience

doi:10.21203/rs.3.rs-8124102/v1

Download PDF

Research Article

Impact of clomipramine prenatal exposure on sexual behavior and reproductive organs in female rats: role of sexual experience

https://doi.org/10.21203/rs.3.rs-8124102/v1

This work is licensed under a CC BY 4.0 License

You are reading this latest preprint version

Depression is a psychiatric disorder that is twice as common in women as in men, with women in the childbearing age being the most at risk of developing depression during pregnancy or the postpartum period. Consequently, antidepressants have been prescribed even when the evidence suggests possible adverse effects on the neurodevelopment of the offspring, considering that antidepressant drugs can be transferred through breast milk. In this way, postnatal (PN) administration of the tricyclic antidepressant clomipramine (CMI) causes persistent behavioral and neurophysiological alterations during adulthood. Contrarily, a rewarding experience as mating improves motivational and copulatory behavior in rodents; therefore, the purpose was to examine the effect of postnatal CMI treatment on female sexual behavior and reproductive tissues, and if sexual experience improves sexual performance. Female rats were divided in two groups, CMI group (30 mg/Kg) and control group (NaCl 0.9%). Each group received a daily subcutaneous injection with CMI or saline solution from the 8 to 21 PN. Behavioral test and histological analysis were performed at 3 months age. The results indicated that postnatal CMI administration disrupts receptive but not proceptive behaviors. Repeated sexual encounters with males reversed the receptivity impairment in CMI-treated females, as it occurs in control rats. Histological data showed that CMI reduces the population of primordial and primary follicles; however, no morphological modifications were detected in the uterine layers. In conclusion, the data show that even when sexual experience improved copulatory behavior in female rats exposed to CMI during the postnatal period, ovarian development was affected, which could compromise fertility.

depression

antidepressants

ovarian follicles

uterus

sexual experience

postnatal exposure

Perinatal depression is a mood disorder that occurs during pregnancy and within the postpartum period. The symptoms can range from mild to severe and can have adverse effects on the mother’s and the infant's health [1]. The use of antidepressant therapy has increased, with the selective serotonin reuptake inhibitors (SSRIs) being the most prescribed. However, another antidepressant, such as a tricyclic antidepressant (TCAs), is clinically indicated [2, 3]. Consequently, both the fetus and neonate are exposed to these drugs, which can cross the placenta, amniotic fluid, and breast milk. This exposure can cause adverse effects during the critical developmental period [4–7].

Recently, clinical evidence indicated that early exposure to antidepressants is associated with pregnancy hypertension, high risk of preterm delivery, lower birth weight, sleep disturbance in infant, delayed development in communication, neonatal abstinence syndrome, lower Apgar score, and increased of risk of heart defects and respiratory distress, among others [8–11]. Additionally, some studies have shown that infants exposed to SSRIs exhibit alterations in both serotonin (5-HT) pathways and the development of some neural circuits involved in emotional processes, which in the long term may have a negative impact on the development of neuropsychological disorders [12]. In fact, children exposed to antidepressants in utero may have a delay in cognitive development [13], an increased risk of attention-deficit/hyperactivity disorder (ADHD), and anxiety disorders during childhood [14, 15], as well as depression disorder in early adolescence [16].

On the other hand, preclinical evidence has shown that rats under perinatal exposure to SSRIs increased defensive anxiety-like behavior, despair behavior, and impairment in spatial learning and memory during adulthood [17, 18], in addition to an altered social behavior [19]. However, no clinical reports suggest adverse effects in reproductive physiology caused by antidepressant exposure. Some preclinical studies in rodents have shown that perinatal exposure to ISSRs alters male and female sexual behavior [20–22], ovarian development and function [23], and the histology of the dimorphic nucleus of the preoptic area [20]. These findings suggest that perinatal antidepressant exposure could reduce fertility and reproductive success. Consistently, postnatal exposure to clomipramine not only alters the copulatory and motivational function of male rats (Velazquez-Moctezuma & Diaz Ruiz, 1992) but also induces long-term alterations in the estrous cyclicity and reproductive behavior of inexperienced female rats. It is likely due to a disruption of the HPA axes (Molina-Jiménez et al., 2018). In this aspect, it is unknown whether sexual experience could improve the alterations in female sexual behavior.

In this regard, female sexual behavior, is considered a natural reward and is characterized by a set of behaviors that include approaching, odor communication (attractivity), active behaviors (proceptivity) of the female focusing on pursuing males soliciting approached, and receptive behaviors such as lordosis, which allows for vaginal penetration by the male [24, 25]. Although it is a behavior regulated by the integration of information from different brain areas that process sensory, motor, rewarding, and motivational information, the impact of gonadal hormones on these neurocircuits is essential for regulating sexual behavior and establishing sexual experience [26, 27]. Consistent with this, the absence of sex hormones reduces the dendritic spines and the density of spines in the medial amygdala and ventromedial hypothalamus areas, which are related to the consummatory phase of sexual behavior. Furthermore, estradiol administration and the cycling fluctuations in gonadal hormones increased spine density in those areas [28, 29]. Moreover, estradiol and progesterone increase the expression of AMPA receptors in the ventromedial hypothalamus and amygdalae, which are fundamental to the long-term potentiation process and plasticity [30].

Sexual experience involves repeated encounters of a sexual nature with a male. These encounters shape neural circuits that generate long-term changes in appetitive and consummatory sexual behavior [31]. For instance, sexual experience increases extracellular dopamine [32] and enhances the presence of filopodial spines in the nucleus accumbens, reflecting a state of plasticity [33]. Moreover, repeated sexual experience increased the density of dendritic spines on granule cells in the dentate gyrus of the hippocampus and restored cognitive function in middle-aged rats [34]. Furthermore, it also increased the density of apical and basal dendrites of pyramidal cells in the prefrontal cortex, enhancing the cognitive flexibility [35]. Additionally, expression of the presynaptic vesicle marker synaptophysin (SYP) is upregulated in the accessory olfactory bulb, which processes pheromone stimuli [36]. In summary, sexual experience modifies the structural and physiological aspects of neural circuits involved in the processing of rewarding sexual behavior. This refines social interactions and mating preferences, thereby enhancing sexual performance.

Thus, the aim of this study was to assess whether sexual experience improves sexual performance in female rats postnatally exposed to CMI. In addition, we investigated the impact of postnatal exposure to CMI on the ovary and uterus using histology, as the serotonergic system is involved in the development of reproductive organs.

Ethics

All procedures were carried out in strict accordance with the Official Mexican Standard NOM-062-ZOO-1999 [37] and the National Institute of Health Guide for the Care and Use of Laboratory Animals [38]. This project was approved by the Ethics Committee of UAMI (CBS.310.18). During experiments, all efforts were made to minimize the number of experimental subjects, animal suffering, and avoid any kind of pain.

2.1. Animals

Male and female Wistar rats from the vivarium of the Universidad Autónoma Metropolitana were used. Animals were kept under standard laboratory conditions, including a reversed 12/12 h dark/light cycle (lights on at 20:00 h), a room temperature of 24 ± 1°C, a humidity of 65 ± 5%, and free access to food (Purina) and drinking water. Initially, receptive female rats were mated with a sexually experienced male in polycarbonate boxes (27 cm × 37 cm × 15 cm) until the presence of the vagina plug. After breeding, male rats were returned to their original box, and pregnant rats were housed individually in polycarbonate boxes (27 cm × 37 cm × 15 cm) until delivery. Three days after birth, pups were separated from their biological mothers and placed in polycarbonate boxes (45 cm × 30 cm × 30 cm) with a foster mother (six pups per foster mother)

2.2. Clomipramine neonatal treatment

Three days after birth, the female rat pups were separated from their biological mothers and lodged with foster mothers. Each foster mother received half the pups from two litters to maintain the same number of pups, n = 6 [39–43]. The male pups were set aside for a different experiment and cross-fostered with different mothers than those used for the females. The female pups were immediately randomly assigned into two groups: the CMI group (n = 12) and the control group (n = 12). Animals of CMI group received a subcutaneous injection of 30 mg/kg (0.1 ml, suspended in saline solution) of clomipramine hydrochloride (Sigma-Aldrich, St Louis, MO, USA), as reported by [44], while the female pups of the control group received the same volume of saline solution (NaCl 0.9%). All treatments were administered daily (10:00 h) from postnatal day (PND) 8 to 21. At the 25 PND, pups were separated from foster mothers and housed in groups (six per cage with the same treatment) in polycarbonate boxes (45 cm × 30 cm × 30 cm). At third months-old, both groups of female rats were subjected to different experimental manipulations.

2.3. Experimental design

The effects of postnatal administration of CMI on the motivational and copulatory behaviors of adult female rats were evaluated during five sessions at three months of age. First, estrous cyclicity was investigated by vaginal smear analysis to determine the phase of the estrous cycle during which the female rats were receptive. Every time a female rat was in the receptive phase, it was set for the sexual behavior test. In this regard, males could perform from 7 to 10 intromissions after ejaculation (Hull and Domínguez, 2007). Then, to avoid a pregnancy, males were alternated during the test days.

After the last evaluation of sexual behavior, rats were euthanized by a lethal dose of pentobarbital sodium (150 mg/kg, i.p.; PISABENTAL® PiSa Agropecuaria S.A. de CV. México). Uterus and ovaries tissue from each rat were obtained, sectioned, mounted and then stained for the histology analysis.

2.4. Vaginal cytology

The estrous cycles of each animal were monitored daily to detect the onset of estrus, the phase during which rats become receptive. Vaginal secretions were collected two hours after the onset of the dark period under red light (40 W). Samples were collected using a glass dropper filled with a saline solution (NaCl 0.9%) by gently inserting the tip into the periphery of the rat vagina orifice, but not deeply. Vaginal smears were placed on microscope slides and observed under a light microscope at 10× and 40× objective lenses [45]. Four phases were identified based on vaginal cytology: proestrus (round and nucleated cells), estrus (cornified cells), metestrus or diestrus I (mixture of round, nucleated cells, cornified cells, and leucocytes), and diestrus or diestrus II (predominance of leucocytes) [46]. Rats in the estrus phase were subjected to the female sexual behavior evaluation.

2.5. Behavioral testing

Female sexual behavior was assessed in a circular Plexiglas arena (diameter: 50 cm; height: 50 cm) during the dark phase between 12:00 and 15:00 h. The test room was illuminated by a dim red light (40 W). To evaluate female sexual behavior, we used sexually experienced males. The males were placed in the arena for 5 min for habituation without the presence of the female rat. Then, females in the receptive phase were placed in the arena and allowed males to perform 10 mounts. This procedure was repeated for five sessions. Additionally, males were alternated during the test days. During the test, we evaluated the incidence of hopping and darting behaviors as measures of proceptivity in females [47]. For receptivity, we considered lordosis, defined as the act of a female lowering her back while raising her tail, thereby exposing her genitals and facilitating the penis insertion, as a measure of receptivity [48, 49]. Lordosis behavior was evaluated by determining the lordosis quotient (LQ = number of lordosis/10 mounts) and the intensity of lordosis. In addition, the intensity of lordosis was also assessed using a 3-point scale as Hardy and Debold [50] proposed: a) 0 or no lordosis; b) 1 or marginal lordosis, characterized by slight flex of spine, slight rise head and hips; c) 2 or normal lordosis which consist in spinal flex and head at an approximate 30° angle with the floor and front paws placed slightly forward and hind legs stiffly straightened; and d) 3 or exaggerated lordosis consisting in a pronounced spinal flex with the head at ≥ 45° angle with the floor.

2.6. Morphometric analysis of the ovaries and uterus

The animals were euthanized with an overdose of pentobarbital sodium injection (PISABENTAL® PiSa Agropecuaria S.A. de CV. México). The uterus and ovaries of both groups were dissected and immediately embedded in a 4% paraformaldehyde solution. Later, paraformaldehyde-fixed uterine and ovarian tissues were washed with 0.1 M phosphate-buffered saline (PBS) solution. Briefly, tissue samples were dehydrated in an ascending series of ethanol concentrations and embedded in paraffin. The ovaries and uterus embedded in paraffin were serially sectioned at 5 µm thickness, and thereafter mounted and stained with Masson’s trichrome stain. Photomicrographs of three stained slices of ovarian and uterine tissue were captured using Coolsnap camera attached to a microscope (model Leica DM750) using 10x magnification. Thereafter, sections were analyzed by using ImageJ software (Image in Java, National Institute of Health, Bethesda, MD, USA). For analysis of the follicle population, sections were analyzed at 40 mm intervals, given the oocyte size (20–30 mm). Moreover, we classified the type of the follicles [51]: primordial follicle, the oocyte is surrounded by one layer of flattened granulose cells; primary follicle, an oocyte surrounded by one layer of differentiated granulose cells; secondary follicle, an oocyte surrounded by many layers of granulosa cells; antral follicle; an oocyte with many layers of granulosa cells and with the presence of one or many cavities containing follicular fluid (antral spaces). The corpus luteum was also counted under the light microscope. Regarding the uterus, we evaluated the diameters and thicknesses of the perimetrium, myometrium, and endometrium.

2.7. Statistical analysis

Data from the female sexual behavior test were ranked, since the Kolmogorov-Smirnov normality test failed to indicate normality [52]. The effect of postnatal CMI treatment during the five sessions of female sexual behavior was analyzed by using a one-way repeated measure (RM) ANOVA to detect differences in proceptive behavior and the quotient of lordosis between groups. The lordosis intensity was evaluated using a two-way RM ANOVA, with neonatal treatment (control and CMI) and lordosis type (L0, L1, L2, and L3) as factors. When the p-value reached < 0.05, a Student-Newman-Keuls post hoc test was applied to determine the source of significance. Moreover, the t-test was used to evaluate differences in morphometric parameters of the ovaries and uterus. Results are plotted as mean ± standard error (SEM). All analyses were performed with Statistica 10 and GraphPad Prism 7.

3.1. Early CMI exposure disrupts sexual behavior in female rats

a) Proceptive behavior

Female adult rats exposed to CMI in postnatal period do not exhibit differences in hops between treatments [F (1, 40) = 0.73, p = 0.41, NS] nor during the sessions of sexual behavior evaluation [F (4, 40) = 0.00, p = 1.0, NS]. Moreover, the interaction of postnatal treatment x session was not significant [F (4, 40) = 0.97, p = 0.43, NS], see Fig. 1a. Regarding to darts behavior, statistical analysis did not found differences neither between treatments [F (1, 40) = 0.08, p = 0.78, NS] nor during sessions [F (4, 40) = -0.00, p = 1.0, NS]. Also, the postnatal treatment x session interaction was not significant [F (4, 40) = 0.28, p = 0.88, NS], see Fig. 1b.

Insert Fig. 1 about here

b) Receptive behavior

Figure 2 shows the effect of CMI postnatal treatment on adult female in five consecutive sessions of sexual behavior. The one-way RM ANOVA did not reach differences between the treatments [F (1, 40) = 0.01, p = 0.90, NS] or during the sessions [F (4, 40) = -0.00, p = 1.0, NS]. Moreover, the treatment x session interaction was not significant [F (4, 40) = 0.05, p = 0.99, NS].

Insert Fig. 2 about here

Regarding the intensity of lordosis (Fig. 3), the two-way RM ANOVA analysis showed differences between groups [F (1, 40) = 14.41, p < 0.0004]. The Student-Newman-Keuls post hoc indicated that CMI rats display less lordosis reflex during the ten mounts performed by the male rat compared with control rat (p < 0.05). The lordosis factor was also significant [F (3, 40) = 10.36, p < 0.00003], regardless the group, rats did not display lordosis or present normal lordosis compared marginal and exaggerated lordosis (SNK, p < 0.05). Moreover, the treatment x lordosis interaction was significant [F (3, 40) = 3.11, p < 0.03]. The post hoc test indicated that CMI group fail to display lordosis behavior (L0) in most of the times that the male rat was mounted. The rest of the times they showed normal (L2), exaggerated (L3) and marginal lordosis (L1). On the contrary, control rats tended to have L2 and L3 rather than L1 or L0 (Fig. 3a). Additionally, the interaction between sessions and lordosis was significant [F(12, 160) = 4.22, p = 0.00001]. Despite the treatment, during the first session rats did not show lordosis in most of the contacts with the male, but as many of sessions as less L0 rats shows, particularly in session 4 whilst in the last session rats returned to their basal condition. In contrast, during the first session, rats performed less normal lordosis or L2, but intensity was increased as the sessions advanced, with the fourth session being the maximum expression of L2. Moreover, a slight increase of L3 lordosis was observed in the second and third sessions; meanwhile, L1 lordosis did not change during the sessions (SNK p > 0.05), see Fig. 3b.

Insert Fig. 3 about here

3.2. Effect of CMI postnatal treatment on reproductive organs

a) Morphometric analysis of the ovaries

Figure 4 showed the effect of CMI postnatal treatment on the ovarian follicle in the ovary. The t-test analysis indicated that CMI rats have fewer number of total follicles compared to control rats [t = 5.190, gl = 7, p < 0.001]. These significant reduction in the number of follicles is due to the reduction in primordial [t = 4.813, gl = 7, p < 0.002] and primary follicles [t = 7.188, gl = 7, p < 0.001] in rats exposed to CMI in early life. Also, although it is not significant, we observed a tendency to have fewer secondary follicles in CMI rats compared to the control group [t = 2.114, gl = 7, p = 0.072, NS]. No statistical differences were found in the number of antral follicles [t = 1.697, gl = 7, p = 0.133, NS] and corpora lutea [t = 0.542, gl = 7, p = 0.604, NS] between groups.

Insert Fig. 4 about here

As shows in Table 1, no differences were found in the perimeter of primordial [t = − 0.640, gl = 7, p = 0.542, NS], primary [t = 1.450, gl = 7, p = 0.190, NS], secondary [t = 1.961, gl = 7, p = 0.091, NS] and antral [t = -0.082, gl = 7, p = 0.937, NS] follicles between groups. Likewise, no statistical differences were found in the diameter of primordial [t = -1.681, gl = 7, p = 0.137, NS], primary [t = -0.099, gl = 7, p = 0.353, NS], secondary [t = 1.373, gl = 7, p = 0.212, NS] and antral [t = -0.599, gl = 7, p = 0.568, NS] follicles between CMI and control rats.

Table 1
Perimeter and diameter (m) of ovarian follicles in control and CMI rats
µ
	Perimeter		Diameter
Follicular stage	Control	CMI	Control	CMI
Primordial follicle	377.85 ± 9.95	385.22 ± 2.62	120.20 ± 3.38	126.80 ± 0.94
Primary follicles	975.12 ± 41.68	887.20 ± 43.22	321.87 ± 14.00	299.95 ± 17.41
Secondary follicle	975.12 ± 41.68	887.20 ± 43.22	798.01 ± 70.91	675.78 ± 43.42
Antral follicle	4885.14 ± 630.41	4959.00 ± 616.90	1638.15 ± 214.90	1466.44 ± 172.11
All values are shown as mean ± SEM. CMI: clomipramine

Insert Table 1 about here

b) Morphometric analysis of the uterus

Regarding the diameter of the uterus, no differences were found in endometrium [t = -1.49, gl = 7, p = 0.17], myometrium [t = -1.16, gl = 7, p = 0.28] and perimetrium diameter [t = -0.89, gl = 7, p = 0.40] compared to control rats. Moreover, statistical analysis indicated no differences in the endometrium [t = 0.47, gl = 7, p = 0.64], myometrium [t = 0.93, gl = 7, p = 0.38] and perimetrium thickness [t = 1.91 gl = 7, p = 0.09] in comparison with control group, see Fig. 5.

Insert Fig. 5 about here

This study evaluates whether sexual experience could improve sexual behavior in female rats exposed to CMI during the postnatal period, and the possible long-term effect of postnatal exposure to CMI on reproductive organs. Results indicated that CMI postnatal administration impairs receptive behavior, but sexual experience acquisition appears to facilitate lordosis independently of the group, in particular in the fourth session, when rats display normal lordosis (L1) most of the time. Moreover, our experiments showed a decrease in the population of primordial and primary follicles in the ovaries of CMI rats, which could be reflected in a reduction in reproductive success.

Exposure to antidepressants during critical periods of early life may cause long-lasting maladaptive behavior in offspring during adulthood, which is described as the neonatal antidepressant exposure syndrome [53]. Accordingly, the neonatal administration of CMI has been used as an important model to understand the neurobiological mechanisms that occur during antidepressant exposure in the postnatal period and the long-term repercussions. In fact, most studies using this model have been conducted on male rats of various strains. These studies suggest that postnatal exposure of CMI causes hyperactivity [54], anxiety-like behavior [55], a reduction in reward-seeking behavior and cognitive disruption [39, 41, 42, 56], impairment in sexual performance and motivation [57], REM sleep suppression [40], alterations in monoamine system on brain structures involved in processing motivational and emotional behavior and a decreased in the response of the HPA axis, normally responding to stress situations [58, 59]. In female rats, some reports indicated that postnatal CMI caused anxiety-like behavior, reduction of 5-HT and dopamine in limbic regions [55], and an increase of immobility, evaluated in forced swimming, which could be reversed by the chronic administration of b-estradiol [60]. Nevertheless, little is known about the effect of postnatal exposure to CMI on reproductive parameters in female rats. Recently, we reported that CMI female rats have fewer estrous cycles due to an extended diestrus phase; these physiological disruptions were accompanied by alterations in the proceptive and consummatory sexual behavior evaluated in a single session [61]. These rats had no prior sexual experience, and it is well known that this latter optimizes sexual behavior repertoire [62]. Therefore, in this study, we evaluated sexual behavior performance during five meeting sessions to explore the influence of sexual experience in female rats exposed to postnatal CMI. Firstly, no changes in the behavior of hops and darts were observed in CMI rats compared to control rats across the five sessions. Similarly, the perinatal exposure to another antidepressant, such as fluoxetine, did not affect the proceptive and receptive behaviors evaluated during the full behavioral estrous cycle [63]. Hence, during the estrus phase, female rats display several motor patterns, such as hops and darts towards males to initiate mating behavior. These behavioral patterns are known as proceptive [24] or paracopulatory behaviors [64] and are considered a measure of sexual motivation because they facilitate copulatory behavior [65].

The expression of proceptive behavior depends on internal stimuli, such as ovarian secretion of estradiol and progesterone [66], and external stimuli, such as pheromones, vocalizations, and social interactions [64, 67, 68]. For instance, when female naive mice are hormonally primed, they prefer the urine pheromones in male over those in female urine, but once they have acquired enough experience, no further hormonal stimulation is necessary to express the male preference [69]. Thus, it is possible that the sexual experience gained during the sessions has generated plastic changes in brain structures related to sexual motivation [70, 71].

On the other hand, the lordosis quotient, which is an indicator of receptivity [24], was not affected by the CMI postnatal treatment. Lordosis is triggered by somatosensory stimuli elicited by the male’s mounting behavior. Although the lordosis reflex is integrated in the spinal medulla, the hormonal status is essential for activating central areas, such as the hypothalamus and brainstem, which regulate lordosis behavior [72–74]. Therefore, we evaluated the type of lordosis displayed during five sessions of sexual behavior, and we found that despite the sessions, CMI female rats did not display lordosis in about 50% of the times that a male approached to perform a mount; but the rest of the times they performed normal or exaggerated lordosis. Conversely, control rats did not display lordosis in only 20% of trials, whereas in 40% of trials they performed normal, marginal, or exaggerated lordosis. In addition, rats from both groups showed increased normal lordosis throughout the sessions. In the fourth session, both groups mostly performed normal lordosis rather than other types. This is consistent with some studies that indicated that a single sexual mating results in lower lordosis levels. It is important to note that females increased their receptivity during mating sessions, with the highest expression in the fourth trial [75], and the effect persists through the fifth session [76]. Hence, repeated sexual encounters with males result in behavioral changes, which are also associated with increased dendritic spines in the mesolimbic system [33] and increased neuronal activation in hypothalamic areas involved in receptivity modulation and in the accessory olfactory bulb [77]. This latter, detects information related to sex pheromones and sends projections to the medial amygdala and hypothalamus, which are involved in the modulation of sexual behavior and neuroendocrine changes [78, 79]. In our study, during the first trial, CMI rats rarely displayed lordosis compared to control rats. It is well documented that sexual receptivity depends on ovarian hormone oscillations, such as estradiol and progesterone [75, 80, 81]. Then, it is possible that CMI rats have an alteration in the HPG axis. Nevertheless, during the subsequent trials, CMI rats exhibited higher levels of normal lordosis, comparable to those of control rats. Perhaps, performing sexual behavior after several trials may allow the acquisition of sexual experience, which shapes the behavior, since it is reported that constant encounters cause changes in neuronal circuits, leading to long-lasting changes in neuroplasticity, improving sexual performance [69]. In addition, we observed that by the fifth session, all rats had returned to the same lordosis patterns displayed during the first session. In this regard, some studies indicated that constant vaginocervical stimulation by the male inhibits the lordosis reflex, accompanied by a rejection of the male during sex encounters [62, 82, 83]; then, although each session was performed every time that females were in estrus, and we allowed ten contacts with male, it is possible that these manipulations were enough to inhibited the lordosis behavior, particularly in CMI rats.

Regarding the morphometric analysis of the follicles, no changes in perimeter or diameter were observed, indicating that postnatal administration of CMI did not cause morphological changes. However, we found that CMI rats have a lower population of primordial and primary follicles. Besides, we observed a non-significant tendency of a decrease in secondary follicles compared to control rats. This is interesting because it is known that the first phase of folliculogenesis in rodents takes place a few days after birth. During this period, primordial follicles are recruited into a growing pool; many of these follicles develop and ovulate, while others undergo normal apoptosis, referred to as atresia. Nevertheless, exposure to xenobiotics significantly increases atresia [84, 85]. Then, it might happen that the postnatal exposure to CMI potentiates the apoptosis process. In contrast, the perinatal exposure to fluoxetine caused a prolonged estrus phase, an increase in the population of total follicles, specifically secondary follicles, and changes in the expression of 5-HT1a receptor and tryptophan hydroxylase 2 (TPH2), which suggests the significance of 5-HT in reproductive organs [23]. Consistently, the early stages of development of follicles are independent of the gonadotropin secretion but depend on paracrine and autocrine signaling [86]. Some studies indicated the participation of serotonergic signaling in folliculogenesis, due to the presence of the enzyme tryptophan hydroxylase 1 (TPH1), SERT transporter, 5-HT, and the 5-HT receptors in mammalian cumulus cells, oocytes, and embryos. Thereby, serotonergic signaling is crucial to the correct follicular and oocyte development [87, 88]. Thus, it is possible that the postnatal administration of CMI modified the serotonergic network by blocking SERT; and that this pharmacological manipulation could cause the quantitative alteration in the population of primordial and primary follicles in these rats.

Finally, no changes in the thickness of the endometrium, myometrium, and perimetrium were observed in the uterus caused by the postnatal administration of CMI. Although no alteration in the morphology of the uterus was found, it is not known if the functionality of the uterus is compromised. For instance, the estrous cycle is regulated by the hormonal oscillation, which also influences the expression of 5-HT receptors in the uterus and the availability of 5-HT. Moreover, this neurotransmitter also interacts with sympathetic fibers of the uterus, controlling its functional activity, even 5-HT signaling is involved in the preimplantation of the embryo, and its development [89, 90]. Further studies will explore the possible effects of postnatal exposure of CMI on peripheral and central serotonergic signaling.

The present study suggests that the acquisition of sexual experience improves consummatory sexual behavior in control rats and rats exposed to CMI. However, early-life exposure to CMI appears to reduce the pool of developing follicles, potentially affecting reproductive success.

5-HT: Serotonin

CMI: Clomipramine

HPA: Hypothalamic-pituitary-adrenal axes

HPG: Hypothalamic-pituitary-gonadal axes

LQ: Lordosis quotient

L0: No lordosis display

L1: Marginal lordosis

L2: Normal lordosis

L3: Exaggerated lordosis

PBS: Phosphate-buffered saline

PN: Postnatal

PND: Postnatal day

S: sessions.

SNK: Student-Newman-Keuls

SSRIs: Selective serotonin reuptake inhibitors

SYP: Synaptophysin

TCAs: Tricyclic antidepressant

TPH1: Tryptophan hydroxylase 1

TPH2: Tryptophan hydroxylase 2

FUNDING

Details During this research, TMJ (CVU 209784) received a fellowship from the Estancia Posdoctoral Vinculada al Fortalecimiento de la Calidad del Posgrado Nacional program (COVIA-0890-2016) granted by Mexico's Consejo Nacional de Ciencia y Tecnología (CONACyT). NGL received the Research Assistant fellowship SNI 53014 granted by CONACyT.

Author Contribution

H.B-J conceived and reviewed the manuscripts. T.M-J conceived, performed the experiments, and wrote the original draft. N.GL performed and analyzed the experiments. MA contributed to the histological staining. C.J-P, R.C.Z., J.A.S-S, and M.F-M reviewed the manuscripts and provided expertise and feedback.

Acknowledgement

We thank Dr. Armando Jesús Martínez Chacón for the statistical assistance provided for this study, and Dr. Juan Francisco Rodríguez-Landa for valuable advice and critical support.

Molenaar NM, Brouwer ME, Kamperman AM, Burger H, Williams AD, Hoogendijk WJG, et al. Recurrence of depression in the perinatal period: Clinical features and associated vulnerability markers in an observational cohort. PLoS ONE. 2019;14:e0212964.
Charlton RA, Jordan S, Pierini A, Garne E, Neville AJ, Hansen AV, et al. Selective serotonin reuptake inhibitor prescribing before, during and after pregnancy: a population-based study in six European regions. BJOG. 2015;122:1010–20. https://doi.org/10.1111/1471-0528.13143.
Lusskin SI, Khan SJ, Ernst C, Habib S, Fersh ME, Albertini ES. Pharmacotherapy for Perinatal Depression. Clin Obstet Gynecol. 2018;61:544–61. https://doi.org/10.1097/GRF.0000000000000365.
Hendrick V, Fukuchi A, Altshuler L, Widawski M, Wertheimer A, Brunhuber MV. Use of sertraline, paroxetine and fluvoxamine by nursing women. Br J Psychiatry. 2001;179:163–6. https://doi.org/10.1192/bjp.179.2.163.
Hendrick V, Stowe ZN, Altshuler LL, Hwang S, Lee E, Haynes D. Placental passage of antidepressant medications. Am J Psychiatry. 2003;160:993–6. https://doi.org/10.1176/appi.ajp.160.5.993.
Kim J, Riggs KW, Misri S, Kent N, Oberlander TF, Grunau RE, et al. Stereoselective disposition of fluoxetine and norfluoxetine during pregnancy and breast-feeding. Br J Clin Pharmacol. 2006;61:155–63. https://doi.org/10.1111/j.1365-2125.2005.02538.x.
Loughhead AM, Fisher AD, Newport DJ, Ritchie JC, Owens MJ, DeVane CL, et al. Antidepressants in amniotic fluid: another route of fetal exposure. Am J Psychiatry. 2006;163:145–7. https://doi.org/10.1176/appi.ajp.163.1.145.
Anderson KN, Lind JN, Simeone RM, Bobo WV, Mitchell AA, Riehle-Colarusso T, et al. Maternal Use of Specific Antidepressant Medications During Early Pregnancy and the Risk of Selected Birth Defects. JAMA Psychiatry. 2020;77:1246–55. https://doi.org/10.1001/jamapsychiatry.2020.2453.
Galbally M, Watson SJ, Boyce P, Nguyen T, Lewis AJ. The mother, the infant and the mother-infant relationship: What is the impact of antidepressant medication in pregnancy. J Affect Disord. 2020;272:363–70. https://doi.org/10.1016/j.jad.2020.03.116.
Ter Horst PGJ, Jansman FGA, van Lingen RA, Smit J-P, de Jong-van LTW, Brouwers JRBJ. Pharmacological aspects of neonatal antidepressant withdrawal. Obstet Gynecol Surv. 2008;63:267–79. https://doi.org/10.1097/OGX.0b013e3181676be8.
Tak CR, Job KM, Schoen-Gentry K, Campbell SC, Carroll P, Costantine M, et al. The impact of exposure to antidepressant medications during pregnancy on neonatal outcomes: a review of retrospective database cohort studies. Eur J Clin Pharmacol. 2017;73:1055–69. https://doi.org/10.1007/s00228-017-2269-4.
Lugo-Candelas C, Cha J, Hong S, Bastidas V, Weissman M, Fifer WP, et al. Associations Between Brain Structure and Connectivity in Infants and Exposure to Selective Serotonin Reuptake Inhibitors During Pregnancy. JAMA Pediatr. 2018;172:525–33. https://doi.org/10.1001/jamapediatrics.2017.5227.
van der Veere CN, de Vries NKS, van Braeckel KNJA, Bos AF. Intra-uterine exposure to selective serotonin reuptake inhibitors (SSRIs), maternal psychopathology, and neurodevelopment at age 2.5years - Results from the prospective cohort SMOK study. Early Hum Dev. 2020;147:105075. https://doi.org/10.1016/j.earlhumdev.2020.105075.
Clements CC, Castro VM, Blumenthal SR, Rosenfield HR, Murphy SN, Fava M, et al. Prenatal antidepressant exposure is associated with risk for attention-deficit hyperactivity disorder but not autism spectrum disorder in a large health system. Mol Psychiatry. 2015;20:727–34. https://doi.org/10.1038/mp.2014.90.
Brandlistuen RE, Ystrom E, Eberhard-Gran M, Nulman I, Koren G, Nordeng H. Behavioural effects of fetal antidepressant exposure in a Norwegian cohort of discordant siblings. Int J Epidemiol. 2015;44:1397–407. https://doi.org/10.1093/ije/dyv030.
Malm H, Brown AS, Gissler M, Gyllenberg D, Hinkka-Yli-Salomäki S, McKeague IW, et al. Gestational Exposure to Selective Serotonin Reuptake Inhibitors and Offspring Psychiatric Disorders: A National Register-Based Study. J Am Acad Child Adolesc Psychiatry. 2016;55:359–66. https://doi.org/10.1016/j.jaac.2016.02.013.
Sprowles JLN, Hufgard JR, Gutierrez A, Bailey RA, Jablonski SA, Williams MT, et al. Perinatal exposure to the selective serotonin reuptake inhibitor citalopram alters spatial learning and memory, anxiety, depression, and startle in Sprague-Dawley rats. Int J Dev Neurosci. 2016;54:39–52. https://doi.org/10.1016/j.ijdevneu.2016.08.007.
Millard SJ, Lum JS, Fernandez F, Weston-Green K, Newell KA. Perinatal exposure to fluoxetine increases anxiety- and depressive-like behaviours and alters glutamatergic markers in the prefrontal cortex and hippocampus of male adolescent rats: A comparison between Sprague-Dawley rats and the Wistar-Kyoto rat model of depression. J Psychopharmacol. 2019;33:230–43. https://doi.org/10.1177/0269881118822141.
Houwing DJ, Heijkoop R, Olivier JDA, Snoeren EMS. Perinatal fluoxetine exposure changes social and stress-coping behavior in adult rats housed in a seminatural environment. Neuropharmacology. 2019;151:84–97. https://doi.org/10.1016/j.neuropharm.2019.03.037.
Rayen I, Steinbusch HWM, Charlier TD, Pawluski JL. Developmental fluoxetine exposure and prenatal stress alter sexual differentiation of the brain and reproductive behavior in male rat offspring. Psychoneuroendocrinology. 2013;38:1618–29. https://doi.org/10.1016/j.psyneuen.2013.01.007.
Rayen I, Steinbusch HWM, Charlier TD, Pawluski JL. Developmental fluoxetine exposure facilitates sexual behavior in female offspring. Psychopharmacology. 2014;231:123–33. https://doi.org/10.1007/s00213-013-3215-5.
Dos Santos AH, Vieira ML, de Azevedo Camin N, Anselmo-Franci JA, Ceravolo GS, Pelosi GG, et al. In utero and lactational exposure to fluoxetine delays puberty onset in female rats offspring. Reprod Toxicol. 2016;62:1–8. https://doi.org/10.1016/j.reprotox.2016.04.006.
Moore CJ, DeLong NE, Chan KA, Holloway AC, Petrik JJ, Sloboda DM. Perinatal Administration of a Selective Serotonin Reuptake Inhibitor Induces Impairments in Reproductive Function and Follicular Dynamics in Female Rat Offspring. Reprod Sci. 2015;22:1297–311. https://doi.org/10.1177/1933719115578925.
Beach FA. Sexual attractivity, proceptivity, and receptivity in female mammals. Horm Behav. 1976;7:105–38. https://doi.org/10.1016/0018-506x(76)90008-8.
Pfaus JG, Jones SL, Flanagan-Cato LM, Blaustein JD. Chapter 50 - Female Sexual Behavior. In: Plant TM, Zeleznik AJ, editors. Knobil and Neill’s Physiology of Reproduction (Fourth Edition) [Internet]. San Diego: Academic; 2015. pp. 2287–370. [cited 2025 Oct 9]. https://doi.org/10.1016/B978-0-12-397175-3.00050-8.
Meisel RL, Mullins AJ. Sexual experience in female rodents: Cellular mechanisms and functional consequences. Brain Res. 2006;1126:56–65. https://doi.org/10.1016/j.brainres.2006.08.050.
Pfaus JG, García-Juárez M, Ordóñez RD, Tecamachaltzi-Silvarán MB, Lucio RA, González-Flores O. Cellular and molecular mechanisms of action of ovarian steroid hormones II: Regulation of sexual behavior in female rodents. Neurosci Biobehavioral Reviews. 2025;168:105946. https://doi.org/10.1016/j.neubiorev.2024.105946.
Calizo LH, Flanagan-Cato LM. Estrogen Selectively Regulates Spine Density within the Dendritic Arbor of Rat Ventromedial Hypothalamic Neurons. J Neurosci. 2000;20:1589. https://doi.org/10.1523/JNEUROSCI.20-04-01589.2000.
Rasia-Filho AA, Fabian C, Rigoti KM, Achaval M. Influence of sex, estrous cycle and motherhood on dendritic spine density in the rat medial amygdala revealed by the Golgi method. Neuroscience. 2004;126:839–47. https://doi.org/10.1016/j.neuroscience.2004.04.009.
Ferri SL, Hildebrand PF, Way SE, Flanagan-Cato LM. Estradiol regulates markers of synaptic plasticity in the hypothalamic ventromedial nucleus and amygdala of female rats. Horm Behav. 2014;66:409–20. https://doi.org/10.1016/j.yhbeh.2014.06.016.
Gutierrez-Castellanos N, Husain BFA, Dias IC, Lima SQ. Neural and behavioral plasticity across the female reproductive cycle. Trends Endocrinol Metabolism. 2022;33:769–85. https://doi.org/10.1016/j.tem.2022.09.001.
Kohlert JG, Meisel RL. Sexual experience sensitizes mating-related nucleus accumbens dopamine responses of female Syrian hamsters. Behav Brain Res. 1999;99:45–52. https://doi.org/10.1016/S0166-4328(98)00068-0.
Staffend NA, Hedges VL, Chemel BR, Watts VJ, Meisel RL. Cell-type specific increases in female hamster nucleus accumbens spine density following female sexual experience. Brain Struct Funct. 2014;219:2071–81. https://doi.org/10.1007/s00429-013-0624-5.
Glasper ER, Gould E. Sexual experience restores age-related decline in adult neurogenesis and hippocampal function. Hippocampus. 2013;23:303–12. https://doi.org/10.1002/hipo.22090.
Glasper ER, LaMarca EA, Bocarsly ME, Fasolino M, Opendak M, Gould E. Sexual experience enhances cognitive flexibility and dendritic spine density in the medial prefrontal cortex. Neurobiol Learn Mem. 2015;125:73–9. https://doi.org/10.1016/j.nlm.2015.07.007.
Marco-Manclus P, Ávila-González D, Paredes RG, Portillo W. Sexual experience in female mice involves synaptophysin-related plasticity in the accessory olfactory bulb. Physiol Behav. 2022;244:113649. https://doi.org/10.1016/j.physbeh.2021.113649.
Muñoz LIO. Norma Oficial Mexicana NOM-062-ZOO-1999, Especificaciones Técnicas para la Producción. Volume 59. Cuidado y Uso de los Animales de Laboratorio; 2001.
National Research Council (US) Committee for the Update of the Guide for the Care and Use of Laboratory Animals. Guide for the Care and Use of Laboratory Animals. 8th ed. Washington (DC): National Academies Press (US); 2011. http://www.ncbi.nlm.nih.gov/books/NBK54050/.
Vogel G, Neill D, Hagler M, Kors D. A new animal model of endogenous depression: a summary of present findings. Neurosci Biobehav Rev. 1990;14:85–91. https://doi.org/10.1016/s0149-7634(05)80164-2.
Vogel GW, Buffenstein A, Minter K, Hennessey A. Drug effects on REM sleep and on endogenous depression. Neurosci Biobehav Rev. 1990;14:49–63. https://doi.org/10.1016/s0149-7634(05)80159-9.
Bonilla-Jaime H, Retana-Marquez S, Velazquez-Moctezuma J. Pharmacological features of masculine sexual behavior in an animal model of depression. Pharmacol Biochem Behav. 1998;60:39–45. https://doi.org/10.1016/s0091-3057(97)00484-x.
Neill D, Vogel G, Hagler M, Kors D, Hennessey A. Diminished sexual activity in a new animal model of endogenous depression. Neurosci Biobehav Rev. 1990;14:73–6. https://doi.org/10.1016/s0149-7634(05)80162-9.
Vázquez-Palacios G, Bonilla-Jaime H, Velázquez-Moctezuma J. Antidepressant effects of nicotine and fluoxetine in an animal model of depression induced by neonatal treatment with clomipramine. Prog Neuropsychopharmacol Biol Psychiatry. 2005;29:39–46. https://doi.org/10.1016/j.pnpbp.2004.08.008.
Martínez-González D, Prospéro-García O, Mihailescu S, Drucker-Colín R. Effects of nicotine on alcohol intake in a rat model of depression. Pharmacol Biochem Behav. 2002;72:355–64. https://doi.org/10.1016/s0091-3057(01)00772-9.
Marcondes FK, Bianchi FJ, Tanno AP. Determination of the estrous cycle phases of rats: some helpful considerations. Braz J Biol. 2002;62:609–14. https://doi.org/10.1590/s1519-69842002000400008.
Freeman ME. Physiology of reproduction. E. Knobil, J. Neill. New York: Raven; 1988.
Madlafousek J, Hliňák Z. Sexual behaviour of the female laboratory rat: Inventory, patterning, and measurement. Behaviour. United Kingdom: Brill Academic Publishers; 1977;63:129–74. https://doi.org/10.1163/156853977X00397
Felicio LF, Palermo-Neto J, Nasello AG. Perinatal bromopride treatment: effects on sexual behavior of male and female rats. Behav Neural Biol. 1989;52:145–51. https://doi.org/10.1016/s0163-1047(89)90257-4.
Morali G, Beyer C. Neuroendocrine control of mammalian estrus behavior. Endocrine Control of Sexual Behavior. New York: Raven; 1979.
Hardy DF, DeBold JF. The relationship between levels of exogenous hormones and the display of lordosis by the female rat. Horm Behavior]. 1971;2:287–97. https://doi.org/10.1016/0018-506X(71)90003-1.
Hirshfield AN, Midgley AR. Morphometric analysis of follicular development in the rat. Biol Reprod. 1978;19:597–605. https://doi.org/10.1095/biolreprod19.3.597.
Conover WJ, Iman RL. Rank Transformations as a Bridge Between Parametric and Nonparametric Statistics. The American Statistician. Volume 35. Ltd: Taylor & Francis; 1981. pp. 124–9. https://doi.org/10.2307/2683975.
Maciag D, Simpson KL, Coppinger D, Lu Y, Wang Y, Lin RC, et al. Neonatal Antidepressant Exposure has Lasting Effects on Behavior and Serotonin Circuitry. Neuropsychopharmacology. 2006;31:47–57. https://doi.org/10.1038/sj.npp.1300823.
Hartley P, Neill D, Hagler M, Kors D, Vogel G. Procedure- and age-dependent hyperactivity in a new animal model of endogenous depression. Neurosci Biobehav Rev. 1990;14:69–72. https://doi.org/10.1016/s0149-7634(05)80161-7.
Andersen SL, Dumont NL, Teicher MH. Differences in behavior and monoamine laterality following neonatal clomipramine treatment. Dev Psychobiol. 2002;41:50–7. https://doi.org/10.1002/dev.10055.
Vogel G, Neill D, Hagler M, Kors D, Hartley P. Decreased intracranial self-stimulation in a new animal model of endogenous depression. Neurosci Biobehav Rev. 1990;14:65–8. https://doi.org/10.1016/s0149-7634(05)80160-5.
Limón-Morales O, Soria-Fregozo C, Arteaga-Silva M, González MH, Vázquez-Palacios G, Bonilla-Jaime H. Hormone replacement with 17β-estradiol plus dihydrotestosterone restores male sexual behavior in rats treated neonatally with clomipramine. Horm Behav. 2014;66:820–7. https://doi.org/10.1016/j.yhbeh.2014.09.014.
Bonilla-Jaime H, Retana-Márquez S, Vazquez-Palacios G, Velázquez-Moctezuma J. Plasma levels of corticosterone and testosterone after sexual activity in male rats treated neonatally with clomipramine. Behav Pharmacol. 2003;14:357–62. https://doi.org/10.1097/01.fbp.0000081784.35927.41.
Ogawa T, Mikuni M, Kuroda Y, Muneoka K, Mori KJ, Takahashi K. Effects of the altered serotonergic signalling by neonatal treatment with 5,7-dihydroxytryptamine, ritanserin or clomipramine on the adrenocortical stress response and the glucocorticoid receptor binding in the hippocampus in adult rats. J Neural Transm Gen Sect. 1994;96:113–23. https://doi.org/10.1007/BF01277933.
Molina-Jímenez T, Landa-Cadena L, Bonilla-Jaime H. Chronic treatment with estradiol restores depressive-like behaviors in female Wistar rats treated neonatally with clomipramine. Horm Behav. 2017;94:61–8. https://doi.org/10.1016/j.yhbeh.2017.06.004.
Molina-Jiménez T, Limón-Morales O, Bonilla-Jaime H. Early postnatal treatment with clomipramine induces female sexual behavior and estrous cycle impairment. Pharmacol Biochem Behav. 2018;166:27–34. https://doi.org/10.1016/j.pbb.2018.01.004.
Meerts SH, Schairer RS, Farry-Thorn ME, Johnson EG, Strnad HK. Previous sexual experience alters the display of paced mating behavior in female rats. Horm Behav. 2014;65:497–504. https://doi.org/10.1016/j.yhbeh.2013.12.015.
Hegstad J, Huijgens PT, Houwing DJ, Olivier JDA, Heijkoop R, Snoeren EMS. Female rat sexual behavior is unaffected by perinatal fluoxetine exposure. Psychoneuroendocrinology. 2020;120:104796. https://doi.org/10.1016/j.psyneuen.2020.104796.
Bergheim D, Chu X, Ågmo A. The function and meaning of female rat paracopulatory (proceptive) behaviors. Behav Processes. 2015;118:34–41. https://doi.org/10.1016/j.beproc.2015.05.011
Uphouse L. Pharmacology of serotonin and female sexual behavior. Pharmacol Biochem Behav. 2014;121:31–42. https://doi.org/10.1016/j.pbb.2013.11.008.
Landau IT, Madden JE. Hormonal regulation of female proceptivity and its influence on male sexual preference in rats. Physiol Behav. 1983;31:679–85. https://doi.org/10.1016/s0031-9384(83)80003-1.
Pfaff DW, Kow L-M, Loose MD, Flanagan-Cato LM. Reverse engineering the lordosis behavior circuit. Horm Behav. 2008;54:347–54. https://doi.org/10.1016/j.yhbeh.2008.03.012.
Petrulis A. Chemosignals, hormones and mammalian reproduction. Horm Behav. 2013;63:723–41. https://doi.org/10.1016/j.yhbeh.2013.03.011.
McCarthy EA, Naik AS, Coyne AF, Cherry JA, Baum MJ. Effect of Ovarian Hormones and Mating Experience on the Preference of Female Mice to Investigate Male Urinary Pheromones. Chem Senses. 2018;43:97–104. https://doi.org/10.1093/chemse/bjx073.
Pitchers KK, Balfour ME, Lehman MN, Richtand NM, Yu L, Coolen LM. Neuroplasticity in the mesolimbic system induced by natural reward and subsequent reward abstinence. Biol Psychiatry. 2010;67:872–9. https://doi.org/10.1016/j.biopsych.2009.09.036.
Zancan M, da Cunha RSR, Schroeder F, Xavier LL, Rasia-Filho AA. Remodeling of the number and structure of dendritic spines in the medial amygdala: From prepubertal sexual dimorphism to puberty and effect of sexual experience in male rats. Eur J Neurosci. 2018;48:1851–65. https://doi.org/10.1111/ejn.14052.
Pfaff DW, Sakuma Y. Facilitation of the lordosis reflex of female rats from the ventromedial nucleus of the hypothalamus. J Physiol. 1979;288:189–202.
Spiteri T, Ogawa S, Musatov S, Pfaff DW, Agmo A. The role of the estrogen receptor α in the medial preoptic area in sexual incentive motivation, proceptivity and receptivity, anxiety, and wheel running in female rats. Behav Brain Res. 2012;230:11–20. https://doi.org/10.1016/j.bbr.2012.01.048.
McGinnis MY, Pfaff DW. Chapter 20 - Sexual Behaviors. In: Fink G, Pfaff DW, Levine JE, editors. Handbook of Neuroendocrinology. San Diego: Academic; 2012. pp. 485–95. https://doi.org/10.1016/B978-0-12-375097-6.10020-4.
Thompson ML, Edwards DA. Experiential and strain determinants of the estrogen-progesterone induction of sexual receptivity in spayed female mice. Horm Behav. 1971;2:299–305. https://doi.org/10.1016/0018-506X(71)90004-3.
Bonthuis PJ, Patteson JK, Rissman EF. Acquisition of sexual receptivity: roles of chromatin acetylation, estrogen receptor-alpha, and ovarian hormones. Endocrinology. 2011;152:3172–81. https://doi.org/10.1210/en.2010-1001.
Marco-Manclus P, Paredes RG, Portillo W. Sexual experience with a known male modulates c-Fos expression in response to mating and male pheromone exposure in female mice. Physiol Behav. 2020;222:112906. https://doi.org/10.1016/j.physbeh.2020.112906.
Petrovich GD, Canteras NS, Swanson LW. Combinatorial amygdalar inputs to hippocampal domains and hypothalamic behavior systems. Brain Res Brain Res Rev. 2001;38:247–89. https://doi.org/10.1016/s0165-0173(01)00080-7.
Gresham R, Li S, Adekunbi DA, Hu M, Li XF, O’Byrne KT. Kisspeptin in the medial amygdala and sexual behavior in male rats. Neurosci Lett. 2016;627:13–7. https://doi.org/10.1016/j.neulet.2016.05.042.
Whalen RE, Gorzalka BB, DeBold JF, Quadagno DM, Ho GK, Hough JC. Studies on the effects of intracerebral actinomycin D implants on estrogen-induced receptivity in rats. Horm Behav. 1974;5:337–43. https://doi.org/10.1016/0018-506x(74)90019-1.
Blaustein JD. Neuroendocrine regulation of feminine sexual behavior: lessons from rodent models and thoughts about humans. Annu Rev Psychol. 2008;59:93–118. https://doi.org/10.1146/annurev.psych.59.103006.093556.
Hardy DF, DeBold JF. Effects of repeated testing on sexual behavior of the female rat. J Comp Physiol Psychol. 1973;85:195–202. https://doi.org/10.1037/h0034895.
Ventura-Aquino E, Fernández-Guasti A. Reduced proceptivity and sex-motivated behaviors in the female rat after repeated copulation in paced and non-paced mating: effect of changing the male. Physiol Behav. 2013;120:70–6. https://doi.org/10.1016/j.physbeh.2013.07.006.
Sobinoff AP, Pye V, Nixon B, Roman SD, McLaughlin EA. Adding insult to injury: effects of xenobiotic-induced preantral ovotoxicity on ovarian development and oocyte fusibility. Toxicol Sci. 2010;118:653–66. https://doi.org/10.1093/toxsci/kfq272.
Mark-Kappeler CJ, Hoyer PB, Devine PJ. Xenobiotic effects on ovarian preantral follicles. Biol Reprod. 2011;85:871–83. https://doi.org/10.1095/biolreprod.111.091173.
Wigglesworth K, Lee K-B, Emori C, Sugiura K, Eppig JJ. Transcriptomic diversification of developing cumulus and mural granulosa cells in mouse ovarian follicles. Biol Reprod. 2015;92:23. https://doi.org/10.1095/biolreprod.114.121756.
Dubé F, Amireault P. Local serotonergic signaling in mammalian follicles, oocytes and early embryos. Life Sci. 2007;81:1627–37. https://doi.org/10.1016/j.lfs.2007.09.034.
Amireault P, Dubé F. Serotonin and its antidepressant-sensitive transport in mouse cumulus-oocyte complexes and early embryos. Biol Reprod. 2005;73:358–65. https://doi.org/10.1095/biolreprod.104.039313.
Veselá J, Rehák P, Mihalik J, Czikková S, Pokorný J, Koppel J. Expression of serotonin receptors in mouse oocytes and preimplantation embryos. Physiol Res. 2003;52:223–8.
Dindyaev SV, Vinogradov SY. The sympathetic neural apparatus of the rat uterus during the sexual cycle. Neurosci Behav Physiol. 2009;39:241–4. https://doi.org/10.1007/s11055-009-9125-7.

No competing interests reported.

Download PDF

Reviews received at journal
31 Dec, 2025
Reviews received at journal
23 Dec, 2025
Reviews received at journal
16 Dec, 2025
Reviewers agreed at journal
11 Dec, 2025
Reviewers agreed at journal
10 Dec, 2025
Reviewers agreed at journal
10 Dec, 2025
Reviewers agreed at journal
05 Dec, 2025
Reviewers invited by journal
03 Dec, 2025
Editor assigned by journal
17 Nov, 2025
Submission checks completed at journal
17 Nov, 2025
First submitted to journal
15 Nov, 2025

You are reading this latest preprint version

Impact of clomipramine prenatal exposure on sexual behavior and reproductive organs in female rats: role of sexual experience

Status:

Version 1

Abstract

Figures

1. INTRODUCTION

2. MATERIAL AND METHODS

2.1. Animals

2.2. Clomipramine neonatal treatment

2.3. Experimental design

2.4. Vaginal cytology

2.5. Behavioral testing

2.6. Morphometric analysis of the ovaries and uterus

2.7. Statistical analysis

3. RESULTS

4. DISCUSSION

5. CONCLUSION

Abbreviations

Declarations

FUNDING

Author Contribution

Acknowledgement

References

Additional Declarations

Status:

Version 1