Effect of prenatal haloperidol exposure on behavioral alterations in rats

Prenatal exposition to haloperidol: A preclinical narrative review

Pre-existing maternal mental disorders may affect the early interactions between mother and baby, impacting the child's psychoemotional development. The typical antipsychotic haloperidol can be used during pregnancy, even with some restrictions. Its prescription is not limited to psychotic disorders, but also to other psychiatric conditions of high incidence and prevalence in the woman's fertile period. The present review focused on the preclinical available data regarding the biological and behavioral implications of embryonic exposure to haloperidol. The understanding of the effects of psychotropic drugs during neurodevelopment is important for its clinical aspect since there is limited evidence regarding the risks of antipsychotic drug treatment in pregnant women and their children. Moreover, a better comprehension of the mechanistic events that can be affected by antipsychotic treatment during the critical period of neurodevelopment may offer insights into the pathophysiology of neurodevelopmental disorders. The findings presented in this review converge to the existence of several risks associated with prenatal exposure to such medication and emphasize the need for further studies regarding its dimensions.

The Influence of Prenatal Exposure to Quetiapine Fumarate on the Development of Dopaminergic Neurons in the Ventral Midbrain of Mouse Embryos

The effects of second-generation antipsychotics on prenatal neurodevelopment, apoptotic neurodegeneration, and postnatal developmental delays have been poorly investigated. Even at standard doses, the use of quetiapine fumarate (QEPF) in pregnant women might be detrimental to fetal development. We used primary mouse embryonic neurons to evaluate the disruption of morphogenesis and differentiation of ventral midbrain (VM) neurons after exposure to QEPF. The dopaminergic VM neurons were deliberately targeted due to their roles in cognition, motor activity, and behavior. The results revealed that exposure to QEPF during early brain development decreased the effects of the dopaminergic lineage-related genes Tyrosine hydroxylase(Th), Dopamine receptor D1 (Drd1), Dopamine transporter (Dat), LIM homeobox transcription factor 1 alfa (Lmx1a), and Cell adhesion molecule L1 (Chl1), and the senescent dopaminergic gene Pituitary homeobox 3 (Pitx3). In contrast, Brain derived neurotrophic factor (Bdnf) and Nuclear receptor-related 1 (Nurr1) expressions were significantly upregulated. Interestingly, QEPF had variable effects on the development of non-dopaminergic neurons in VM. An optimal dose of QEPF (10 µM) was found to insignificantly affect the viability of neurons isolated from the VM. It also instigated a non-significant reduction in adenosine triphosphate formation in these neuronal populations. Exposure to QEPF during the early stages of brain development could also hinder the formation of VM and their structural phenotypes. These findings could aid therapeutic decision-making when prescribing 2nd generation antipsychotics in pregnant populations.

Prenatal Venlafaxine Exposure-Induced Neurocytoarchitectural and Neuroapoptotic Degeneration in Striatum and Hippocampus of Developing Fetal Brain, Manifesting Long-term Neurocognitive Impairments in Rat Offspring

Depression is a leading cause of disability which at its worst leads to suicide. Its treatment relies on psychotherapy in combination with certain antidepressants (AD_(s)) from various classes such as tricyclics, selective serotonin reuptake inhibitors, or serotonin and norepinephrine reuptake inhibitors (SNRIs). Among SNRIs, venlafaxine (VEN) is one such most commonly prescribed AD which is recently reported to be in the top 50 most prescribed drugs in the USA. Depression during pregnancy is a common condition, where prescribing an AD becomes necessary as untreated depression during pregnancy has its own complications for both mother and the child. This, probably, is why an incredible rise has been reported in prescribing ADs like VEN to pregnant women in the recent past, despite some studies, including the one from our own group, having reported the in-utero VEN-induced apoptotic neurodegeneration in the fetal neocortex and the consequent neurobehavioral anomalies in adulthood. However, there still exists a lack of insight into the effects of intrauterine exposures of VEN on other fetal brain regions like the hippocampus (HPC) and striatum (STR) and the consequent effects on their cognitive and emotional wellbeing in later life. Hence, this study has been conducted where pregnant Charles-Foster (CF) rats were oral gavaged with VEN (25, 40, and 50 mg/kg bw) from gestation day (GD) 05-19. On GD-19, half of the control and treated dams were euthanized to collect their fetuses. Fetal brains were dissected and processed for reactive oxygen species (ROS) estimation neurohistopathology and confocal microscopic studies. The remaining dams were allowed to deliver naturally, and litters were reared for up to 8 weeks then tested for their cognitive abilities by the Morris water maze test and for their emotionality by the Forced swimming test. Our results showed substantial neurocytoarchitectural deficits in both HPC and STR, along with enhanced ROS levels and apoptotic neurodegenerations. Furthermore, VEN-treated young rat offsprings displayed cognitive impairments and depressive behavior as the long-lasting impact of VEN in a dose-dependent manner. So it may be inferred that prenatal VEN-induced oxidative stress causes apoptotic neurodegeneration leading to neuronal loss in HPC and STR which consequently affects the development of the said brain areas resulting in impaired cognitive and emotional abilities of young adult offsprings. Therefore, extrapolating these findings in animal models, caution may be taken before prescribing VEN to pregnant women, especially during the sensitive phase of pregnancy.

Use of Prescribed Psychotropics during Pregnancy: A Systematic Review of Pregnancy, Neonatal, and Childhood Outcomes

This paper reviews the findings from preclinical animal and human clinical research investigating maternal/fetal, neonatal, and child neurodevelopmental outcomes following prenatal exposure to psychotropic drugs. Evidence for the risks associated with prenatal exposure was examined, including teratogenicity, neurodevelopmental effects, neonatal toxicity, and long-term neurobehavioral consequences (i.e., behavioral teratogenicity). We conducted a comprehensive review of the recent results and conclusions of original research and reviews, respectively, which have investigated the short- and long-term impact of drugs commonly prescribed to pregnant women for psychological disorders, including mood, anxiety, and sleep disorders. Because mental illness in the mother is not a benign event, and may itself pose significant risks to both mother and child, simply discontinuing or avoiding medication use during pregnancy may not be possible. Therefore, prenatal exposure to psychotropic drugs is a major public health concern. Decisions regarding drug choice, dose, and duration should be made carefully, by balancing severity, chronicity, and co-morbidity of the mental illness, disorder, or condition against the potential risk for adverse outcomes due to drug exposure. Globally, maternal mental health problems are considered as a major public health challenge, which requires a stronger focus on mental health services that will benefit both mother and child. More preclinical and clinical research is needed in order to make well-informed decisions, understanding the risks associated with the use of psychotropic medications during pregnancy.

Long-term neurodevelopmental consequences of intrauterine exposure to lithium and antipsychotics: a systematic review and meta-analysis

Lithium and antipsychotics are often prescribed to treat bipolar disorder or psychotic disorders in women of childbearing age. Little is known about the consequences of these medications during pregnancy for the developing child. The objective of this article is to systematically review findings from preclinical and clinical studies that have examined the neurodevelopmental consequences of intrauterine exposure to lithium and antipsychotics. A systematic search was performed in Embase, Medline, Web of Science, PsychINFO, Cochrane, and Google Scholar. Clinical and experimental studies were selected if they investigated neurodevelopment of offspring exposed to lithium or antipsychotics during gestation. Quality of clinical and preclinical studies was assessed by the Newcastle-Ottawa Scale and the SYRCLE's risk of Bias tool, respectively. In total, 73 studies were selected for qualitative synthesis and three studies were selected for quantitative synthesis. Of preclinical studies, 93% found one or more adverse effects of prenatal exposure to antipsychotics or lithium on neurodevelopment or behaviour. Only three clinical cohort studies have investigated the consequences of lithium exposure, all of which reported normal development. In 66% of clinical studies regarding antipsychotic exposure, a transient delay in neurodevelopment was observed. The relative risk for neuromotor deficits after in utero exposure to antipsychotics was estimated to be 1.63 (95% CI 1.22-2.19; I2 = 0%). Preclinical studies suggest long-term adverse neurodevelopmental consequences of intrauterine exposure to either lithium or antipsychotics. However, there is a lack of high-quality clinical studies. Interpretation is difficult, since most studies have compared exposed children with their peers from the unaffected population, which did not allow correction for potential influences regarding genetic predisposition or parental psychiatric illness.

Prenatal Exposure to Antipsychotics Disrupts the Plasticity of Dentate Neurons and Memory in Adult Male Mice

BACKGROUND

With the growing use of second-generation antipsychotics for the treatment of a spectrum of psychiatric illnesses in pregnancy, concerns have been raised about the long-term impact of these medications on offspring neurodevelopment. However, preclinical and clinical evidence on the lasting effects of prenatal antipsychotic exposure is still sparse.

METHODS

Risperidone, a widely used second-generation antipsychotic, and haloperidol, a representative first-generation antipsychotic, were administered to pregnant C57BL/6N mice from embryonic day 6 to 16. Behavioral tests, immunohistochemical staining, Golgi-Cox technique, and western blot were used to determine the effects of prenatal antipsychotic exposure on the plasticity of the dentate gyrus and related behavior in adult male mice.

RESULTS

Both prenatal haloperidol- and risperidone-exposed mice showed recognition memory deficits but had no anxiety-related behavior. In addition, both prenatal haloperidol and risperidone exposure impaired the proliferation and maturation of adult-born dentate granule cells. We found that haloperidol exposure decreased dendritic length of dentate granule cells, while risperidone had no effect. However, both drugs inhibited dendrite branching in granule cells. Haloperidol exposure also significantly reduced total spine density in the middle dendritic segment of dentate gyrus. Prenatally risperidone-exposed mice only displayed a loss in thin and mushroom spines of infrapyramidal blade of dentate gyrus. Collectively, prenatal haloperidol exposure exerted more robust negative effects than risperidone.

CONCLUSION

These data provide evidence for the long-term programming effects of early-life exposure to antipsychotics on hippocampal plasticity and behavior.

In utero exposure to atypical antipsychotic drug, risperidone: Effects on fetal neurotoxicity in hippocampal region and cognitive impairment in rat offspring

Clinical studies indicate that about one-third of pregnant women with psychotic symptoms are exposed to either typical or atypical antipsychotic drugs (APDs). Reports on prenatal subject/model are lacking hence, the present study was undertaken to investigate the effect of prenatal exposure to risperidone (RIS) on the fetal hippocampus, and their related functional changes in young rat offspring. In this study, pregnant Wistar rats were exposed to equivalent therapeutic doses of RIS at 0.8mg/kg, 1.0mg/kg, and 2.0mg/kg BW from gestation days (GD) 6 to 20. On GD 21, about half of the pregnant subjects of each group were euthanized, their fetuses were collected, fetal brains dissected, and processed for neurohistopathological evaluation. Remaining pregnant dams were allowed to deliver naturally and reared up to 8weeks of age for neurobehavioral study under selected paradigms of cognition. Our results indicate that there was a significant decrease in the thickness of fetal hippocampus with the disturbed cytoarchitectural pattern, and volume of striatum and choroid plexus was also reduced. Furthermore, RIS treated young rat offspring displayed memory impairment on different mazes of learning and memory. The current study concludes that maternal exposure to clinically relevant doses of RIS may induce neurostructural changes in developing hippocampus and striatum, and cognitive sequelae in young offspring, respectively. Therefore, caution must be taken before prescribing this drug to pregnant subjects, especially during the sensitive phase of brain development. Hence, clinical correlation of animal data is urgently warranted.

Activity-dependent reduction of dopamine D2 receptors during a postnatal critical period of plasticity in rat striatum is not affected by prenatal haloperidol treatment

Motor activity induced in the Circling Training test (CT) during a postnatal (PN) critical period of plasticity (PN30-37) produces a long-lasting decrease in the number of binding sites and mRNA expression levels of the dopamine D2 receptor (D2R) in rat striatum. Prenatal exposure to the antipsychotic haloperidol also decreases postnatal levels of the striatal D2R in the offspring. We examined whether such fetal exposure to haloperidol could affect the activity-dependent reduction of the D2R system during the critical period. Half of the male offspring exposed to either haloperidol (2.5 mg/kg/day), i.p.) or saline during gestational days 5-18 were subjected to the CT during the critical period, while the remaining represented CT control animals. The adult number of binding sites and mRNA expression levels of the striatal D2R at PN90 were not changed by prenatal haloperidol treatment alone. On the other hand, only pups subjected to the CT during the critical period showed decreases in both studied parameters, regardless the prenatal treatment. These findings indicated that the postnatal reduction of the striatal D2R binding induced prenatally by haloperidol does not affect long-lasting activity-dependent plastic changes on the same receptor system elicited by motor activity in an ontogenetic critical period of plasticity in rat striatum.

Annual Research Review: New frontiers in developmental neuropharmacology: can long-term therapeutic effects of drugs be optimized through carefully timed early intervention?

Our aim is to present a working model that may serve as a valuable heuristic to predict enduring effects of drugs when administered during development. Our primary tenet is that a greater understanding of neurodevelopment can lead to improved treatment that intervenes early in the progression of a given disorder and prevents symptoms from manifesting. The immature brain undergoes significant changes during the transitions between childhood, adolescence, and adulthood. Such changes in innervation, neurotransmitter levels, and their respective signaling mechanisms have profound and observable changes on typical behavior, but also increase vulnerability to psychiatric disorders when the maturational process goes awry. Given the remarkable plasticity of the immature brain to adapt to its external milieu, preventive interventions may be possible. We intend for this review to initiate a discussion of how currently used psychotropic agents can influence brain development. Drug exposure during sensitive periods may have beneficial long-term effects, but harmful delayed consequences may be possible as well. Regardless of the outcome, this information needs to be used to improve or develop alternative approaches for the treatment of childhood disorders. With this framework in mind, we present what is known about the effects of stimulants, antidepressants, and antipsychotics on brain maturation (including animal studies that use more clinically-relevant dosing paradigms or relevant animal models). We endeavor to provocatively set the stage for altering treatment approaches for improving mental health in non-adult populations.

Upregulation of cannabinoid type 1 receptors in dopamine D2 receptor knockout mice is reversed by chronic forced ethanol consumption

BACKGROUND

The anatomical proximity of the cannabinoid type 1 (CNR1/CB1R) and the dopamine D2 receptors (DRD2), their ability to form CB1R-DRD2 heteromers, their opposing roles in locomotion, and their involvement in ethanol's reinforcing and addictive properties prompted us to study the levels and distribution of CB1R after chronic ethanol intake, in the presence and absence of DRD2.

METHODS

We monitored the drinking patterns and locomotor activity of Drd2+/+ and Drd2-/- mice consuming either water or a 20% (v/v) ethanol solution (forced ethanol intake) for 6 months and used the selective CB1 receptor antagonist [³H]SR141716A to quantify CB1R levels in different brain regions with in vitro receptor autoradiography.

RESULTS

We found that the lack of DRD2 leads to a marked upregulation (approximately 2-fold increase) of CB1R in the cerebral cortex, the caudate-putamen, and the nucleus accumbens, which was reversed by chronic ethanol intake.

CONCLUSIONS

The results suggest that DRD2-mediated dopaminergic neurotransmission and chronic ethanol intake exert an inhibitory effect on cannabinoid receptor expression in cortical and striatal regions implicated in the reinforcing and addictive properties of ethanol.

Early exposure to haloperidol or olanzapine induces long-term alterations of dendritic form

Exposure of the developing brain to a wide variety of drugs of abuse (e.g., stimulants, opioids, ethanol, etc.) can induce life-long changes in behavior and neural circuitry. However, the long-term effects of exposure to therapeutic, psychotropic drugs have only recently begun to be appreciated. Antipsychotic drugs are little studied in this regard. Here, we quantitatively analyzed dendritic architecture in adult mice treated with paradigmatic typical- (haloperidol) or atypical (olanzapine) antipsychotic drugs at developmental stages corresponding to fetal or fetal plus early childhood stages in humans. In layer 3 pyramidal cells of the medial and orbital prefrontal cortices and the parietal cortex and in spiny neurons of the core of the nucleus accumbens, both drugs induced significant changes (predominantly reductions) in the amount and complexity of dendritic arbor and the density of dendritic spines. The drug-induced plasticity of dendritic architecture suggests changes in patterns of neuronal connectivity in multiple brain regions that are likely to be functionally significant.

Drugs, biogenic amine targets and the developing brain

Defects in the development of the brain have a profound impact on mature brain functions and underlying psychopathology. Classical neurotransmitters and neuromodulators, such as dopamine, serotonin, norepinephrine, acetylcholine, glutamate and GABA, have pleiotropic effects during brain development. In other words, these molecules produce multiple diverse effects to serve as regulators of distinct cellular functions at different times in neurodevelopment. These systems are impacted upon by abuse of a variety of illicit drugs, neurotherapeutics and environmental contaminants. In this review, we describe the impact of drugs and chemicals on brain formation and function in animal models and in human populations, highlighting sensitive periods and effects that may not emerge until later in life.

Anxiogenesis in adult rats treated chronically with cocaine during adolescence: effects of extended abstinence and 8-OH-DPAT treatment

Our laboratory has recently observed the development of an anxiogenic response after a short abstinence period ( approximately 10 days) in young adult rats treated repeatedly with cocaine during adolescence. The present study was conducted to determine if this effect persists into adulthood following extended durations of abstinence and whether it could be modulated with the 5-HT(1A) agonist (+/-)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT). Accordingly, 30-day-old rats were injected with either 10mg/kg cocaine or saline for 8 consecutive days. Approximately 8 weeks after the final injection, anxiety levels in subjects were assessed with an elevated zero maze with a second assessment performed 4 weeks thereafter. Shortly prior to each test session, half the subjects in each of the two adolescent drug conditions received injections of 300 microg/kg 8-OH-DPAT while the other half received injections of the vehicle. Based on total time spent in the open areas of the maze, the results obtained at the first abstinent duration indicated that adolescent cocaine treatment did not induce an anxiogenic response. Assessment of maze behavior at the second abstinent duration was aided with a digital tracking and computerized scoring system (LimeLight, Actimetrics). Similar to the results obtained at the first abstinent duration, the amount of time spent in the open areas of the maze was unrelated to prior cocaine treatment. However, cocaine-treated rats did show evidence of an anxiogenic response at this abstinent duration based on more frequent entries into and out of the open and enclosed areas of the maze, more frequent and longer durations of exploratory bouts beyond the perimeter of the maze, excessive number of cautious protrusions into the open areas, and faster running velocities through the open areas. These results were not artifacts of generalized motor activation in that comparable total distance traveled scores were noted for all subjects. Treatment with 8-OH-DPAT shortly prior to elevated zero maze testing normalized these behaviors induced by adolescent cocaine. It is concluded that the anxiogenic response produced by cocaine exposure during adolescence persists 12 weeks beyond cessation of drug treatment and that this effect is reversible with 8-OH-DPAT. In addition, the results underscore the importance of taking multiple measures when assessing anxiety in experimental animals. Implications for the neurobiology of drug abuse and the role of serotonin are discussed.

Postnatal haloperidol eliminates the deficit in circling behavior produced by prenatal exposure to the same drug

Up to 35% of pregnant women take psychotropic drugs at least once during gestation [Austin and Mitchell, 1998]. From concurrent animal and human evidence, it has been proposed that exposure to several psychoactive medications in utero or during lactation increases the risk for permanent brain disorders. Present preventive or therapy practices applied on humans for this type of long-lasting behavioral alterations are mainly based on empirical results. Here, we test an experimental approach designed to counteract a circling performance deficit that appears in Sprague-Dawley rats at puberty on exposure to the dopaminergic blocker haloperidol (HAL) during gestation [J.L. Brusés, J.M. Azcurra, The circling training: A behavioral paradigm for functional teratology testing, in: P.M. Conn (Ed.), Paradigms for the study of behavior, Acad. Press, New York, 1993, pp. 166-179. Method Neurosci. 14]. Gestational exposure to HAL (GD 5-18, 2.5 mg/kg/day ip) induced the expected circling activity decrease in the offspring at the fifth week of life. When prenatal exposure to HAL was continued through lactation (PD5-21, 1.5 mg/kg/day ip), rats otherwise showed a control-like circling performance. No difference was yet found between lactation-only, HAL-exposed pups and saline (SAL)-treated controls (n=8 each group). We further performed saturating (3H)-spiroperidol (SPI) binding assays on striatal P2 membrane fractions 2 months later. The dopamine-type D2-specific binding results suggested that above circling behavior findings could be partially explained by enduring HAL-induced neurochemical changes. The role of critical periods of sensitivity as transient windows for opportunistic therapies for behavioral teratology is discussed.

Prenatal exposure to methylphenidate hydrochloride decreases anxiety and increases exploration in mice

The administration of methylphenidate (MPH) to girls and adults has increased in the last decade. Given the similarity of MPH to cocaine and the increasing possibility of embryonic exposure, the gestational effects of this stimulant on development must be considered. We administered MPH (5 mg/kg) or saline to female CD-1 mice at three different periods during pregnancy [embryonic (E) days 8-10, 12-14, and 16-18]. MPH-exposed pups were compared with the saline-treated pups for changes in physical, motor, and behavioral development at postnatal day (PND) 3-11. In adulthood (>60 days of age) these mice were tested in the open field, elevated plus maze, and water maze, and given an acute MPH challenge. We observed limited effects of MPH exposure on early developmental variables. In adulthood, mice exposed to MPH on E8-10 exhibited a general decrease in anxiety-related behaviors and a concomitant increase in exploratory behavior. Prenatal MPH exposure did not alter water maze performance or the response to an acute MPH challenge. Our data provide an initial overview of the possible effects occurring as a result of prenatal exposure to MPH, and strongly suggest that further studies of the in utero and developmental effects of psychostimulants are needed.