Prenatal Fluoxetine Exposure Research Articles

Prenatal Fluoxetine Exposure Influences Glucocorticoid Receptor-Mediated Activity in the Prefrontal Cortex of Adolescent Rats Exposed to Acute Stress.

Any deviation from the programmed processes of brain development may modify its formation and functions, thereby precipitating pathological conditions, which often become manifest in adulthood. Exposure to a challenge during crucial periods of vulnerability, such as adolescence, may reveal molecular changes preceding behavioral outcomes. Based on a previous study showing that prenatal fluoxetine (FLX) leads to the development of an anhedonic-like behavior in adult rats, we aimed to assess whether the same treatment regimen (i.e., fluoxetine during gestation; 15 mg/kg/day) influences the ability to respond to acute restraint stress (ARS) during adolescence. We subjected the rats to a battery of behavioral tests evaluating the development of various phenotypes (cognitive deficit, anhedonia, and anxiety). Furthermore, we carried out molecular analyses in the plasma and prefrontal cortex, a brain region involved in stress response, and whose functions are commonly altered in neuropsychiatric conditions. Our findings confirm that prenatal manipulation did not affect behavior in adolescent rats but impaired the capability to respond properly to ARS. Indeed, we observed changes in several molecular key players of the hypothalamic pituitary adrenal axis, particularly influencing genomic effects mediated by the glucocorticoid receptor. This study highlights that prenatal FLX exposure influences the ability of adolescent male rats to respond to an acute challenge, thereby altering the functionality of the hypothalamic-pituitary-adrenal axis, and indicates that the prenatal manipulation may prime the response to challenging events during this critical period of life.

Prenatal SSRI Exposure Increases the Risk of Autism in Rodents via Aggravated Oxidative Stress and Neurochemical Changes in the Brain.

The mechanisms underlying selective serotonin reuptake inhibitor (SSRI) use during pregnancy as a major autism risk factor are unclear. Here, brain neurochemical changes following fluoxetine exposure and in an autism model were compared to determine the effects on autism risk. The study was performed on neonatal male western albino rats which were divided into Groups one (control), two (propionic acid [PPA]-induced autism model), and three (prenatal SSRI-exposed newborn rats whose mothers were exposed to 5 mg/kg of fluoxetine over gestation days 10-20). SSRI (fluoxetine) induced significant neurochemical abnormalities in the rat brain by increasing lipid peroxide (MDA), Interferon-gamma (IFN-γ), and caspase-3 levels and by depleting Glutathione (GSH), Glutathione S-transferases (GST), Catalase, potassium (K+), and Creatine kinase (CK) levels, similarly to what has been discovered in the PPA model of autism when compared with control. Prenatal fluoxetine exposure plays a significant role in asset brain damage in newborns; further investigation of fluoxetine as an autism risk factor is thus warranted.

Sex differences in long-term behavioral alterations, especially anxiety, following prenatal fluoxetine exposure in C57BL/6 mice

Evidence demonstrates that psychiatric disorders during pregnancy are detrimental to the offspring. Many disorders are treated with SSRIs and increasing numbers of pregnant women now receive these drugs during gestation. The long-term neurobehavioral consequences of prenatal SSRI exposure require further evaluation. This study examined the effects of prenatal fluoxetine exposure in mice in an extensive battery of behaviors related to neurodevelopment, mood, social, and repetitive behaviors. C57BL/6J dams were administered fluoxetine at a low (0.6 mg/kg/day) or high (6 mg/kg/day) dose or saline from embryonic days 8 to 18. Juvenile mice were tested for changes in ultrasonic vocalizations and neuromotor development. In adulthood, offspring were tested for changes in behaviors related to anxiety, depression, social, and repetitive behaviors. Prenatal exposure to fluoxetine impaired surface righting reflex at P5, and sex-dependently reduced the frequency of ultrasonic vocalizations in juvenile males but not females. In adulthood, both males and females prenatally exposed to high, but not low, doses of fluoxetine exhibited an increase in repetitive behaviors in the marble burying task and a decrease in sucrose preference. Males, but not females, exposed to fluoxetine exhibited increased anxiety-related behaviors in the elevated plus maze. Prenatal fluoxetine exposure did not affect other adult behaviors including social preference, self-grooming, passive avoidance and open field activity. These findings suggest males are more sensitive than females to disruptions in serotonin balance during prenatal development and highlight the need for additional systematic and mechanistic studies to evaluate the impact of fluoxetine exposure during other periods of gestation.

Effects of maternal fluoxetine treatment on behavioural despair and learned helplessness parameters of depression in the rat progeny

Behavioural teratological effects of prenatal fluoxetine exposure were investigated on behavioural despair and learned helplessness parameters of depression in rats. Pregnant rats were administered fluoxetine (5 and 10 mg/kg/day) orally once a day during the gestation days 13 to 20. The pups born were subjected to forced swimming test of behavioural despair and learned helplessness test at 8 weeks of age. The results indicated that prenatal fluoxetine treatment (5 and 10 mg/kg/day) induced significant increase in time of immobility in forced swimming test and number of escape failures in learned helplessness test in rat offspring. Rat offspring treated with 5 and 10 mg/kg fluoxetine during the prenatal period displayed dose dependent significant increase in time of immobility in behavioural despair test and number of escape failures in learned helplessness test in comparison to control rat offspring. The findings highlight that prenatal fluoxetine treatment caused depressive like behavioural alterations in the rat offspring.

Prenatal exposure to selective serotonin reuptake inhibitors (SSRI) increases aggression and modulates maternal behavior in offspring mice.

Selective serotonin reuptake inhibitors (SSRI) are commonly prescribed antidepressant drugs in pregnant women. SSRIs cross the placental barrier and affect serotonergic neurotransmission in the fetus. Although no gross SSRI-related teratogenic effects were reported, infants born following prenatal exposure to SSRIs are at higher risk for various developmental abnormalities. The aim of this study was to examine the effects of prenatal SSRI on social and maternal behavior in mice. To this end, pregnant female dams were exposed to saline or fluoxetine (FLX) throughout pregnancy, and the behavior of the offspring was examined. The results indicate that in utero FLX increased aggression in adult males and delayed emergence of maternal behavior in adult females. Social exploration and recognition memory were not affected by prenatal FLX exposure. These findings support the notion that alterations in the development of serotonergic pathways following prenatal exposure to SSRIs are associated with changes in social and maternal behavior throughout life.

Prenatal fluoxetine exposure affects cytokine and behavioral response to an immune challenge.

Fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI) is a commonly prescribed antidepressant drug in pregnant women. FLX readily crosses the placenta, consequently altering serotonergic neurotransmission in the fetus and causing physiological and behavioral disturbances in the newborn. Studies have shown that serotonin plays a role in modulating immune signaling. Thus, the goal of this study was to assess the effects of prenatal exposure to FLX on the response to an immune challenge in offspring mice. Male and female mice were prenatally exposed to FLX and later injected with lipopolysaccharide (LPS) at different stages of development. Results indicated that prenatal FLX modulated aspects of the response to the endotoxin challenge. Prenatal FLX diminished the secretion of interleukin (IL)-6 in adult male and female mice. Prenatal exposure to FLX further suppressed TNFα and augmented IL-1β secretion in adult males. Early effects of LPS (within 24h of administration) on body weight and food consumption were diminished by prenatal exposure to FLX in adult mice. Delayed effects of LPS (within 60h of administration) were modulated by prenatal FLX in young animals. These results provide an indication that prenatal modulations of the serotonergic system had lasting implications for host response to an immune challenge. These findings may contribute to the understanding of the effects of prenatal environment on the development of physiological systems that are important to coping with infectious challenges, and assist in understanding the limitations and precautions that should be taken in the use of SSRIs during pregnancy.

Prenatal fluoxetine exposure induces life-long serotonin 5-HT 3 receptor-dependent cortical abnormalities and anxiety-like behaviour

Selective serotonin reuptake inhibitors (SSRIs) are the first choice of drugs to treat depression and anxiety during pregnancy. However, there is evidence that in utero exposure to SSRIs leads to adverse effects in offspring. Here we show that in mice, the adverse effects of the widely used antidepressant and SSRI fluoxetine are critically dependent on the 5-HT 3 receptor, the only ligand-gated ion channel in the family of serotonin receptors. In utero exposure to fluoxetine induces anxiety-like behavior in wildtype, but not in mice lacking the 5-HT 3 receptor. In addition to this behavioral phenotype, these mice show life-long abnormalities of cortical cytoarchitecture, which can be reversed in vitro by pharmacological block of 5-HT 3 receptors. Moreover, the effect of fluoxetine on the development of cortical neurons is absent in 5-HT 3 receptor knockout mice. These findings pinpoint the pivotal role of serotonergic signaling during development and provide a novel basis to investigate the adverse effects of the use of fluoxetine during pregnancy. This article is part of a Special Issue entitled ‘Post-Traumatic Stress Disorder’.

Fluoxetine administration to pregnant rats increases anxiety-related behavior in the offspring

Fluoxetine (Prozac®) is the most frequently prescribed drug to battle depression in pregnant women, but its safety in the unborn child has not yet been established. Fluoxetine, a selective serotonin reuptake inhibitor, crosses the placenta, leading to increased extracellular serotonin levels and potentially neurodevelopmental changes in the fetus. The purpose of this study was to elucidate the long-term consequences of prenatal fluoxetine in rats. Pregnant rats were injected daily with 12mg/kg fluoxetine or vehicle from gestational day11 until birth, and the behavior of the offspring was monitored. Plasma fluoxetine transfer from mother to pup was 83%, and high levels of fluoxetine (13.0μg/g) were detected in the pup brain 5h after the last injection. Fluoxetine-treated dams gave birth to litters 15% smaller than usual and to pups of reduced weight (until postnatal day7). Furthermore, prenatal fluoxetine exposure significantly increased anxiety in the novelty-suppressed feeding test, the footshock-induced conditioned place aversion test, and the elevated plus maze test (following footshock pre-exposure) during adulthood, and also significantly decreased components of social play behavior at 4weeks of age, and a strong tendency for increased self-grooming and making less contact in adults. Behavioral despair, anhedonia, and sexual behavior were not different between treatment groups. Finally, the hypothermic response to the 5-HT(1A) agonist flesinoxan was observed at a lower dose in prenatally fluoxetine-exposed rats than in controls. Prenatal fluoxetine exposure in rats leads to detrimental behavioral outcomes in later life, which may partly be due to altered 5-HT(1A) receptor signaling.

Prenatal fluoxetine exposure may be associated with CV anomalies

Prenatal fluoxetine exposure may be associated with CV anomalies

Prenatal fluoxetine exposure may be associated with CV anomalies

Prenatal fluoxetine exposure may be associated with CV anomalies

Modulation of Serotonin Transporter Function during Fetal Development Causes Dilated Heart Cardiomyopathy and Lifelong Behavioral Abnormalities

BackgroundWomen are at great risk for mood and anxiety disorders during their childbearing years and may become pregnant while taking antidepressant drugs. In the treatment of depression and anxiety disorders, selective serotonin reuptake inhibitors (SSRIs) are the most frequently prescribed drugs, while it is largely unknown whether this medication affects the development of the central nervous system of the fetus. The possible effects are the product of placental transfer efficiency, time of administration and dose of the respective SSRI.Methodology/Principal FindingsIn order to attain this information we have setup a study in which these parameters were measured and the consequences in terms of physiology and behavior are mapped. The placental transfer of fluoxetine and fluvoxamine, two commonly used SSRIs, was similar between mouse and human, indicating that the fetal exposure of these SSRIs in mice is comparable with the human situation. Fluvoxamine displayed a relatively low placental transfer, while fluoxetine showed a relatively high placental transfer. Using clinical doses of fluoxetine the mortality of the offspring increased dramatically, whereas the mortality was unaffected after fluvoxamine exposure. The majority of the fluoxetine-exposed offspring died postnatally of severe heart failure caused by dilated cardiomyopathy. Molecular analysis of fluoxetine-exposed offspring showed long-term alterations in serotonin transporter levels in the raphe nucleus. Furthermore, prenatal fluoxetine exposure resulted in depressive- and anxiety-related behavior in adult mice. In contrast, fluvoxamine-exposed mice did not show alterations in behavior and serotonin transporter levels. Decreasing the dose of fluoxetine resulted in higher survival rates and less dramatic effects on the long-term behavior in the offspring.ConclusionsThese results indicate that prenatal fluoxetine exposure affects fetal development, resulting in cardiomyopathy and a higher vulnerability to affective disorders in a dose-dependent manner.

Developmental and Behavioral Consequences of Prenatal Fluoxetine

Background: Fluoxetine, a selective serotonin reuptake inhibitor, is the most commonly prescribed antidepressant drug for pregnant women. Studies regarding the teratogenic effect of fluoxetine on human and animal models are mainly concerned with structural malformation (congenital anomalies). Aim: Hence, the present study was planned to evaluate the postnatal behavioral effects of fluoxetine on albino rats. Methods: Three groups of female rats received either distilled water or doses of fluoxetine 8 and 12 mg/kg orally from the 6th to the 20th day of pregnancy. Weaning of the pups was done on the 21st day followed by a battery of behavioral tests to assess for any behavioral effect. The tests included negative geotaxis, open field exploration, rota-rod test, elevated plus maze and passive avoidance test. Results: In the present study there was no change in the gestational length of pregnancy, no premature birth or miscarriage during pregnancy. A high dose of in utero fluoxetine resulted in a decrease in birth weight of the offspring and also reduced weight gain during the preweaning period. No major congenital abnormalities were observed in the offspring exposed to fluoxetine. Prenatal fluoxetine exposure at high dose caused an initial transient delay in motor development and this poor motor activity was transient and not permanent. However, prenatal exposure to fluoxetine at a higher dose showed a favorable effect on learning and memory in water maze and passive avoidance tests. Conclusions: From the present study, it may be concluded that prenatal fluoxetine causes a transient delay in motor development but does not adversely affect the postnatal behavioral consequences.

Long-term effects of fluoxetine or vehicle administration during pregnancy on behavioral outcomes in guinea pig offspring.

Assessment of the benefits versus risks associated with antidepressant use during pregnancy must include an analysis of possible drug effects on fetal development. Human studies indicate that prenatal fluoxetine exposure is associated with adverse neonatal outcomes. Animal modeling may provide useful information concerning possible long-term effects of prenatal fluoxetine exposure. Limitations in previous such studies using rat models may be overcome using a guinea pig model in which fluoxetine is delivered by osmotic pump throughout pregnancy. Initial experiments measured the half-life of fluoxetine and dosing required to achieve human therapeutic blood levels in the guinea pig. In subsequent experiments, guinea pigs received fluoxetine or vehicle via osmotic pump or no treatment throughout pregnancy. Outcome measures included: pregnancy characteristics, weight gain, and, in offspring as adults, pain threshold, acoustic startle responses and prepulse inhibition. There was no effect of treatment group on gestation length, number of live-births or still-births, maternal or offspring weight gain, and acoustic startle responses. In adult offspring, pain threshold was decreased by vehicle treatment during gestation. Prenatal fluoxetine increased pain threshold, relative to vehicle controls. Prepulse inhibition of startle was increased in adult offspring treated prenatally with either vehicle or fluoxetine compared to no treatment. The guinea pig provides a practicable and clinically relevant model of prenatal fluoxetine exposure. Adult guinea pigs exposed to fluoxetine prenatally showed increased thermal pain thresholds but no change in prepulse inhibition, indicating selective long-term effects of prenatal fluoxetine on serotonin-modulated behaviors. Further studies on long-term effects of prenatal fluoxetine on nociception are warranted.

A Developmental Neurotoxicity Evaluation of the Effects of Prenatal Exposure to Fluoxetine in Rats

A Developmental Neurotoxicity Evaluation of the Effects of Prenatal Exposure to Fluoxetine in Rats. Vorhees, C. V., Acuff-Smith, K. D., Schilling, M. A., Fisher, J. E., Moran, M. S., and Buelke-Sam, J. (1994). Fundam. Appl. Toxicol. 23, 194-205. Fluoxetine is a widely used serotonin reuptake inhibitor effective in the treatment of depression. This experiment assessed the potential developmental neurotoxicity of fluoxetine. Sprague-Dawley CD rats were treated once per day on Days 7-20 of gestation with 0, 1, 5, or 12 mg/kg of fluoxetine (free base) dissolved in distilled water. One control group received water by gavage; animals in this group were provided food and water ad libitum. The second control group (PF) also received water by gavage; animals in this group had their food and water restricted by pair-feeding and watering them to the 12 mg/kg fluoxetine group. Litters were culled to 12 after birth and offspring (male/female pairs) were tested neurobehaviorally at three developmental stages (preweaning, juvenile, and adult). At each stage, two pairs per litter received tests of locomotor activity, acoustic startle, and startle after administration of one of two pharmacological challenges (one pair each receiving fluoxetine or apomorphine). Two pairs were also tested for spontaneous alternation, passive avoidance, and complex learning in a water maze. At the highest dose, fluoxetine caused maternal weight loss during pregnancy, reduced litter sizes at birth, and increased neonatal mortality. No effects on long-term growth or survival were seen. Prenatal fluoxetine exposure produced no significant effects on locomotor activity, spontaneous alternation, passive avoidance, or water maze performance. A few scattered interactions involving treatment group were obtained on startle, but no pattern of treatment-related changes was evident. Regional wet and dry brain weights taken at each stage were not affected by prenatal fluoxetine exposure. The data suggest that fluoxetine is not developmentally neurotoxic in the rat.