Low doses of cocaine decrease, and high doses increase, anxiety-like behavior and brain progestogen levels among intact rats

Sexual effects of commonly used recreational psychostimulants in women and the female rat model

INTRODUCTION

Recreational psychostimulants have been associated with increased sexual activity or changes in sexual function in women, but every drug in this class has not shown consistent sexual effects in scientific studies. Further, some studies in female animal models may recapitulate the effects observed in humans, while others produce conflicting results. Overall, though, published studies on the sexual effects of recreational stimulants in women are lacking.

OBJECTIVES

The objective of this manuscript was to review the published sexual effects of prominent recreational psychostimulants in women and in the female rat model.

METHODS

Literature searches for "any years" were performed through PubMed and Google Scholar. Keywords for the searches included "amphetamine," "methamphetamine," "MDMA," "ecstasy," "3,4-methylenedioxymethamphetamine," "cocaine," "caffeine," "sex," "sexual," "female," and "women." Studies in humans and using animal models were included.

RESULTS

Older studies have shown that amphetamine produces a positive sexual effect in women, but often the sample size was too small to draw generalizable conclusions. Methamphetamine also has a positive effect on several sexual domains in women, as well as on vaginal lubrication. 3,4-Methylenedioxymethamphetamine may have a negative or positive effect on sexual activity, but often enhances the sensual aspects of sex. Though low doses of cocaine may heighten the sexual experience, most women who use cocaine experience negative sexual effects. Caffeine has been shown to enhance a physiological measure of arousal, vaginal blood flow, but based on our searches, no studies have investigated the subjective sexual effects of the drug.

CONCLUSION

Different recreational psychostimulants produce varying effects on sexual behavior and responses in women and female animal models, but more research is needed to understand these effects better.

Ephedrine and cocaine cause developmental neurotoxicity and abnormal behavior in zebrafish

Ephedrine (EPH) and cocaine (COC) are illegal stimulant drugs, and have been frequently detected in aquatic environments. EPH and COC have negative effects on the nervous system and cause abnormal behaviors in mammals and fish at high concentrations, but their mechanisms of neurotoxicity remain unclear in larvae fish at low concentrations. To address this issue, zebrafish embryos were exposed to EPH and COC for 14 days post-fertilization (dpf) at 10, 100, and 1000 ng L-1. The bioaccumulation, development, behavior, cell neurotransmitter levels and apoptosis were detected to investigate the developmental neurotoxicity (DNT) of EPH and COC. The results showed that EPH decreased heart rate, while COC increased heart rate. EPH caused cell apoptosis in the brain by AO staining. In addition, behavior analysis indicated that EPH and COC affected spontaneous movement, touch-response, swimming activity and anxiety-like behaviors. EPH and COC altered the levels of the neurotransmitters dopamine (DA) and γ-aminobutyric acid (GABA) with changes of the transcription of genes related to the DA and GABA pathways. These findings indicated that EPH and COC had noticeable DNT in the early stage of zebrafish at environmentally relevant concentrations.

The influence of sex and reproductive cycle on cocaine-induced behavioral and neurobiological alterations: a review

This systematic review (SR) was aimed at answering two questions: (1) how sex and ovarian hormones alter behavior associated with cocaine use; (2) which possible neurobiological mechanisms explain behavioral differences. Three different researchers conducted a search in PUBMED for all kinds of articles published between the years of 1991 to 2021 on the theme "reproductive cycle and cocaine", "estrous cycle and cocaine", "menstrual cycle and cocaine", "fluctuation of ovarian hormones and cocaine", "estrogen and cocaine" and "progesterone and cocaine". Sixty original studies were identified and subdivided into experimental rodent studies and clinical trials. Experimental studies were characterized by author/year, species/strain, sex/number, age/weight, dose/route/time of administration, hormonal assessment, or administration. Clinical trials were characterized by author/year, sex/number, age, exclusion criterion, dose/route of administration/time of cocaine, and hormonal assessment. Results gathered showed that rodent females develop increased consumption, seeking behavior, craving, relapse, locomotion, increases in stress and anxiety, among other behavioral alterations during peaks of estrogen. These observations are related to the direct effects played by ovarian hormones (in particularly estradiol), in dopamine, but also in serotonin neurons, and in brain regions such as the tegmental area, the nucleus accumbens, the hypothalamus, the amygdala and the prefrontal cortex. Increased sensitization to cocaine presented by high estradiol females was linked to the activation of a CBR1-mediated mechanism and GABA-A-dependent suppression of inhibitory synaptic activity of the prelimbic prefrontal cortex. Estradiol facilitation of cocaine-increased locomotion and self-administration was shown to require the release of glutamate and the activation of metabotropic glutamate receptors subtype 5. Clinical studies also tend to point to a stimulatory effect of estradiol on cocaine sensitization and a neuroprotective effect of progesterone. In conclusion, the results of the present review indicate a need for further preclinical and clinical trials and neurobiological studies to better understand the relationship between sex and ovarian hormones on cocaine sensitization.

Hormonal milieu drives economic demand for cocaine in female rats

There are substantial sex differences in drug abuse, and a key feature of cocaine addiction is pathologically high motivation for drug. We investigated the role of ovarian hormones on cocaine demand in female rats using a within-session threshold behavioral economics (BE) procedure, which allows us to compare motivation for drug across hormonal states and sex while controlling for differences in dose and intake. This approach quantifies demand elasticity (α) and free consumption (Q₀, consumption at null effort) to determine motivation for cocaine. Overall, female rats showed greater motivation for cocaine compared to males. However, this difference was cycle phase-dependent - motivation for cocaine when females were in proestrus was lower compared to the same animals across cycle phases, and overall similar to that of males. Hormonal cycle phase accounted for 70% of the within-subject variance in demand elasticity, obscuring other individual differences in female demand. High serum progesterone (P4; e.g., in proestrus) predicted decreased cocaine motivation (high demand elasticity), whereas serum estradiol (E2) correlated to greater intake at null effort (Q₀). However, individual differences were revealed across OVX females, who displayed a range of demand elasticity, as seen in males. E2 replacement in OVX females increased motivation for cocaine, whereas P4 replacement decreased motivation. We also found that as few as 4 weeks of cocaine self-administration accelerated estropause in female rats as young as 12 weeks old. By 13 weeks of self-administration, proestrus epochs were no longer observed, and cocaine demand was potentiated by persistent estrus in all females. Thus, P4 signaling is a key modulator of cocaine demand in females that may underlie previously observed sex differences in addiction phenotypes.

The effects of cocaine exposure in adolescence: Behavioural effects and neuroplastic mechanisms in experimental models

Drug addiction is a devastating disorder with a huge economic and social burden for modern society. Although an individual may slip into drug abuse throughout his/her life, adolescents are at higher risk, but, so far, only a few studies have attempted to elucidate the underlying cellular and molecular bases of such vulnerability. Indeed, preclinical evidence indicates that psychostimulants and adolescence interact and contribute to promoting a dysfunctional brain. In this review, we have focused our attention primarily on changes in neuroplasticity brought about by cocaine, taking into account that there is much less evidence from exposure to cocaine in adolescence, compared with that from adults. This review clearly shows that exposure to cocaine during adolescence, acute or chronic, as well as contingent or non‐contingent, confers a vulnerable endophenotype, primarily, by causing changes in neuroplasticity. Given the close relationship between drug abuse and psychiatric disorders, we also discuss the translational implications providing an interpretative framework for clinical studies involving addictive as well as affective or psychotic behaviours.

Repeated crack cocaine administration alters panic-related responses and delta FosB immunoreactivity in panic-modulating brain regions

Crack cocaine is the crystal form of cocaine, produced by adding sodium bicarbonate to cocaine base paste. Brazil is the largest consumer of crack cocaine in the world. Users of crack cocaine show important physiological and behavioral alterations, including neuropsychiatric symptoms, such as anxiety-related symptoms. Nevertheless, few pre-clinical studies have been previously performed to understand the neurobiological effects of crack cocaine. The purpose of the present study was to investigate effects of the subchronic treatment (5 days, IP) of rats with crack cocaine in an animal model of anxiety/panic, the elevated T-maze (ETM). The ETM model allows the measurement of two behavioral defensive responses, avoidance and escape, in clinical terms, respectively, associated to generalized anxiety and panic disorder, the two main psychiatric conditions that accompany substance use disorders. Immediately after the ETM model, animals were tested in an open field for locomotor activity assessment. Analysis of delta FosB protein immunoreactivity was used to map areas activated by crack cocaine exposure. Results showed that crack treatment selectively altered escape displayed by rats in the ETM test, inducing either a panicolytic (18 mg/kg IP) or a panicogenic-like effect (25 and 36 mg/kg IP). These effects were followed by the altered functioning of panic-modulating brain regions, i.e., the periaqueductal gray and the dorsal region and lateral wings of the dorsal raphe nucleus. Treatment with 36 mg/kg of crack cocaine also increased locomotor activity. These are the first observations performed with crack cocaine in a rodent model of anxiety/panic and contribute to a better understanding of the behavioral and neurobiological effects of crack cocaine.

Behavioral and neurobiological alterations induced by chronic use of crack cocaine

Crack cocaine is the crystal form of cocaine and can be smoked, and rapidly absorbed, and, in part for this reason, is potently addictive. It is hypothesized that crack cocaine is able to induce important changes in different tissues and organs, and thus dramatically alter behavior. Nevertheless, which alterations in the central nervous system are related to its frequent use is still a matter of discussion. The present study is a literature review of articles published between the years 2008 and 2018 on the theme 'crack cocaine and brain' available in PUBMED, MEDLINE, EMBASE, and Google scholar databases. The results show that the use of crack cocaine induces important behavioral, neuroanatomical, and biochemical alterations. The main behavioral sequelae include cognitive and emotional changes, such as increased anxiety and depressive symptoms, attention and memory deficits, and hyperactivity. Among the neurobiological alterations are reductions in the activity of the prefrontal, anterior cingulate cortex, and nucleus accumbens. Molecular changes include decreases in neurotrophic factors and increases in oxidative stress and inflammatory cytokines, which may be responsible for the morphological alterations observed. It is also hypothesized that these neurobiological changes might explain the emotional and cognitive dysfunctions experienced by crack cocaine addicts.

Neurobehavioural complications of sleep deprivation: Shedding light on the emerging role of neuroactive steroids

Sleep deprivation (SD) is associated with a broad spectrum of cognitive and behavioural complications, including emotional lability and enhanced stress reactivity, as well as deficits in executive functions, decision making and impulse control. These impairments, which have profound negative consequences on the health and productivity of many individuals, reflect alterations of the prefrontal cortex (PFC) and its connectivity with subcortical regions. However, the molecular underpinnings of these alterations remain elusive. Our group and others have begun examining how the neurobehavioural outcomes of SD may be influenced by neuroactive steroids, a family of molecules deeply implicated in sleep regulation and the stress response. These studies have revealed that, similar to other stressors, acute SD leads to increased synthesis of the neurosteroid allopregnanolone in the PFC. Whereas this up-regulation is likely aimed at counterbalancing the detrimental impact of oxidative stress induced by SD, the increase in prefrontal allopregnanolone levels contributes to deficits in sensorimotor gating and impulse control, signalling a functional impairment of PFC. This scenario suggests that the synthesis of neuroactive steroids during acute SD may be enacted as a neuroprotective response in the PFC; however, such compensation may in turn set off neurobehavioural complications by interfering with the corticolimbic connections responsible for executive functions and emotional regulation.

Effects of non-contingent cocaine on 3alpha-androstanediol. I. Disruption of male sexual behavior

One of the hallmarks of drug abuse is a reduction in the salience of, and motivation for, natural rewards, such as mating. The effects of psychostimulants on male sexual interest and performance are conflicting; use of psychostimulants can produce increases in risky sexual behaviors but have detrimental effects on sexual ability. We hypothesize that these conflicting effects on sexual behavior are due to interactions between cocaine and androgens, such as testosterone and its neuroactive metabolite, 3α-androstanediol (3α-diol). Male rats were administered saline or cocaine (5, 10, or 20mg/kg, i.p.). Motor behavior was observed in the first 30min following drug-administration, and then sexual responding was assessed for 15min. Levels of androgens (testosterone, 3ɑ-diol, and testosterone's aromatized metabolite, estradiol) were measured in circulation and brain regions (frontal cortex, hippocampus, hypothalamus/striatum (hypo/str), and midbrain). Cocaine had no effect on measures of sexual interest (i.e. anogenital investigation). However, cocaine had substantial effects on consummatory sexual behaviors, such as the latency to mount/intromit and the number of sexual contacts. Frontal cortex and hypo/str 3α-diol levels were strongly correlated with consummatory behaviors in saline administered rats; however, this relationship was disrupted by cocaine at all dosages, concomitant with impaired sexual behaviors. Additionally, there was a shift in metabolism at low dosages of cocaine to push testosterone metabolism in the midbrain towards 3α-diol. On the contrary, moderate and high dosages of cocaine shifted testosterone metabolism towards estradiol. These data demonstrate that the association between cortical and hypo/str 3α-diol levels and sexual behavior of male rats is disrupted by non-contingent cocaine and that there may be dose-dependent effects of acute cocaine on androgen metabolism.

Effects of non-contingent cocaine on 3 alpha-androstanediol. II. Disruption of lordosis of proestrous rats

Drug use influences sexual behavior, performance, and can be associated with increased sexual risk-taking. Our prior results using an animal model indicate that progestogens contribute to hormonally-mediated changes in sexual behavior of female rodents during acute cocaine exposure. Androgens, such as testosterone, and its metabolite 3ɑ-androstanediol (3α-diol), and estradiol, are known to influence male sexual behavior, but can also alter the expression of sexual behavior of female rodents. As such, we investigated the influence of endogenous androgen and estradiol fluctuations on cocaine-mediated changes in motor behavior and sexual receptivity of rats during diestrous or proestrous phases of the estrous cycle. Female rats were administered saline or cocaine (5, 10, or 20mg/kg, i.p.). Motor behavior was observed in the first 30min following drug administration, and then sexual responding was assessed for 15min. Cocaine decreased aggressive behavior in response to attempted mounts by a male among non-receptive (diestrous) rats and inhibited sexual behavior among sexually receptive (proestrous) rats. Cocaine dose-dependently altered concentrations of testosterone metabolites (estradiol and 3α-diol), but not testosterone, which correlated to motor and sexual behaviors of diestrous and proestrous rats, respectively. These data suggest that actions of 3α-diol may be involved in female sexual and motor behavior in response to cocaine, in a cycle-dependent manner.

Estrous cycle and HIV-1 Tat protein influence cocaine-conditioned place preference and induced locomotion of female mice

The HIV-1 trans-activator of transcription (Tat) protein, interacts with psychostimulants to potentiate cocaine-reward in rodents. Sex steroids may protect against Tat-induced deficits. Female GT-tg transgenic mice conditionally-expressed Tat protein targeted to brain via a doxycycline-dependent, GFAP-linked promoter. Mice were tested for cocaine-conditioned place preference (CPP) and cocaine-induced locomotion when in the proestrous (high-hormone) or diestrous (low-hormone) phases of their estrous cycle. Cocaine-CPP was potentiated by Tat induction via 50, 100, or 125 (but not 25) mg/kg doxycycline daily treatment for 7 days. Diestrous mice exposed to Tat protein demonstrated significantly greater cocaine-CPP than did proestrous mice. Tat induction interacted with estrous cycle to decrease acute cocaine-induced locomotion among Tat-induced diestrous mice, but not their uninduced or proestrous counterparts, and attenuated cocaine-sensitization. In a cocaine-challenge, previously cocaine-sensitized mice demonstrated greater cocaine-locomotion over cocaine-naive counterparts and Tat-induction attenuated locomotion. Altogether, data demonstrate Tat and circulating sex steroid influences over cocaine-reward and psychostimulation.

A single exposure to cocaine during development elicits regionally-selective changes in basal basic Fibroblast Growth Factor (FGF-2) gene expression and alters the trophic response to a second injection

RATIONALE

During adolescence, the brain is maturing and more sensitive to drugs of abuse that can influence its developmental trajectory. Recently, attention has been focused on basic fibroblast growth factor (FGF-2) given that its administration early in life enhances the acquisition of cocaine self-administration and sensitization at adulthood (Turner et al. (Pharmacol Biochem Behav 92:100-4, 2009), Clinton et al. (Pharmacol Biochem Behav103:6-17, 2012)). Additionally, we found that abstinence from adolescent cocaine exposure long lastingly dysregulates FGF-2 transcription (Giannotti et al. (Psychopharmacology (Berl) 225:553-60, 2013 ).

OBJECTIVES

The objectives of the study are to evaluate if (1) a single injection of cocaine (20 mg/kg) at postnatal day 35 alters FGF-2 messenger RNA (mRNA) levels and (2) the first injection influences the trophic response to a second injection (10 mg/kg) provided 24 h or 7 days later.

RESULTS

We found regional differences in the FGF-2 expression pattern as either the first or the second injection of cocaine by themselves upregulated FGF-2 mRNA in the medial prefrontal cortex and nucleus accumbens while downregulating it in the hippocampus. The first injection influences the trophic response of the second. Of note, 24 h after the first injection, accumbal and hippocampal FGF-2 changes produced by cocaine in saline-pretreated rats were prevented in cocaine-pretreated rats. Conversely, in the medial prefrontal cortex and hippocampus 7 days after the first injection, the cocaine-induced FGF-2 changes were modified by the subsequent exposure to the psychostimulant.

CONCLUSIONS

These findings show that a single cocaine injection is sufficient to produce enduring changes in the adolescent brain and indicate that early cocaine priming alters the mechanisms regulating the trophic response in a brain region-specific fashion.

Cocaine-, caffeine-, and stress-evoked cocaine reinstatement in high vs. low impulsive rats: treatment with allopregnanolone

BACKGROUND

Previous research indicates that individual differences in traits such as impulsivity, avidity for sweets, and novelty reactivity are predictors of several aspects of drug addiction. Specifically, rats that rank high on these behavioral measures are more likely than their low drug-seeking counterparts to exhibit several characteristics of drug-seeking behavior. In contrast, initial work suggests that the low drug-seeking animals are more reactive to negative events (e.g., punishment and anxiogenic stimuli). The goal of this study was to compare high and low impulsive rats on reinstatement of cocaine-seeking behavior elicited by cocaine (COC) and by negative stimuli such as the stress-inducing agent yohimbine (YOH) or a high dose of caffeine (CAFF). An additional goal was to determine whether treatment with allopregnanolone (ALLO) would reduce reinstatement (or relapse) of cocaine-seeking behavior under these priming conditions.

METHODS

Female rats were selected as high (HiI) or low (LoI) impulsive using a delay-discounting task. After selection, they were allowed to self-administer cocaine for 12 days. Cocaine was then replaced with saline, and rats extinguished lever responding over 16 days. Subsequently, rats were pretreated with either vehicle control or ALLO, and cocaine seeking was reinstated by injections of COC, CAFF, or YOH.

RESULTS

While there were no phenotype differences in maintenance and extinction of cocaine self-administration or reinstatement under control treatment conditions, ALLO attenuated COC- and CAFF-primed reinstatement in LoI but not HiI rats.

CONCLUSIONS

Overall, the present findings suggest that individual differences in impulsive behavior may influence efficacy of interventions aimed to reduce drug-seeking behavior.

Motivated behaviors and levels of 3α,5α-THP in the midbrain are attenuated by knocking down expression of pregnane xenobiotic receptor in the midbrain ventral tegmental area of proestrous rats

INTRODUCTION

Progesterone (P4 ) and its product, 5α-pregnan-3α-ol-20-one (3α,5α-THP), act in the midbrain ventral tegmental area (VTA) to alter motivated behaviors, such as mating, and motor and anxiety behavior. Of interest is whether 3α,5α-THP formation requires the pregnane xenobiotic receptor (PXR), which is expressed in the midbrain of rats.

AIM

The role of PXR in the midbrain for 3α,5α-THP formation, which precedes modulation of motivated behaviors, was investigated.

METHODS

Rats had estrous cycle phase determined and were assessed when they were in diestrus or proestrus. Diestrous and proestrous rats were infused with control or antisense oligodeoxyribonucleotides (AS-ODNs) targeted against PXR to the VTA.

MAIN OUTCOME MEASURES

In pilot studies, PXR gene and protein expression in the midbrain were determined with quantitative reverse transcriptase polymerase chain reaction and Western blotting, respectively. Diestrous and proestrous rats infused with control or AS-ODNs to the VTA were tested for anxiety (open field and plus maze), social (social interaction), and sexual (paced mating) behavior. Expression of PXR in the midbrain was verified with Western blotting. Plasma estradiol, P4 , dihydroprogesterone (DHP), and 3α,5α-THP levels, and brain P4 , DHP, and 3α,5α-THP levels were measured. We predicted that proestrous rats infused with PXR AS-ODNs would have decreased anti-anxiety, social, and sexual behavior, lower midbrain expression of PXR, and lower midbrain levels of 3α,5α-THP compared with controls.

RESULTS

Results supported the hypothesis that formation of 3α,5α-THP requires PXR and may be important for motivated behaviors. PXR AS-ODN, compared with control, infusions to the VTA reduced PXR expression and 3α,5α-THP levels in the midbrain and attenuated sexual receptivity of proestrous rats.

CONCLUSIONS

Knockdown of PXR in the midbrain reduces 3α,5α-THP levels and sexual receptivity of proestrous rats. Thus, PXR in the midbrain may be required for the observed increase in 3α-5α-THP during proestrus, which has subsequent effects on motivated, reproductive behaviors.

Dissociating behavioral, autonomic, and neuroendocrine effects of androgen steroids in animal models

Developments in behavioral assessment, autonomic and/or baseline reactivity, psychopharmacology, and genetics, have contributed significantly to the assessment of performance-enhancing drugs in animal models. Particular classes of steroid hormones: androgenic steroids are of interest. Anecdotally, the performance enhancing effects of androgens are attributed to anabolic events. However, there is a discrepancy between anecdotal evidence and investigative data. While some androgen steroids may promote muscle growth (myogenesis), effects of androgens on performance enhancement are not always seen. Indeed, some effects of androgens on performance may be attributable to their psychological and cardiovascular effects. As such, we consider androgen effects in terms of their behavioral, autonomic, and neuroendocrine components. Techniques are discussed in this chapter, some of which are well established, while others have been more recently developed to study androgen action. Androgens may be considered for their positive impact, negative consequence, or psychotropic properties. Thus, this review aims to elucidate some of the effects and/or mechanisms of androgens on behavioral, autonomic, and/or neuroendocrine assessment that may underlie their controversial performance enhancing effects.

Effects and Mechanisms of 3α,5α,-THP on Emotion, Motivation, and Reward Functions Involving Pregnane Xenobiotic Receptor

Progestogens [progesterone (P(4)) and its products] play fundamental roles in the development and/or function of the central nervous system during pregnancy. We, and others, have investigated the role of pregnane neurosteroids for a plethora of functional effects beyond their pro-gestational processes. Emerging findings regarding the effects, mechanisms, and sources of neurosteroids have challenged traditional dogma about steroid action. How the P(4) metabolite and neurosteroid, 3α-hydroxy-5α-pregnan-20-one (3α,5α-THP), influences cellular functions and behavioral processes involved in emotion/affect, motivation, and reward, is the focus of the present review. To further understand these processes, we have utilized an animal model assessing the effects, mechanisms, and sources of 3α,5α-THP. In the ventral tegmental area (VTA), 3α,5α-THP has actions to facilitate affective, and motivated, social behaviors through non-traditional targets, such as GABA, glutamate, and dopamine receptors. 3α,5α-THP levels in the midbrain VTA both facilitate, and/or are enhanced by, affective and social behavior. The pregnane xenobiotic receptor (PXR) mediates the production of, and/or metabolism to, various neurobiological factors. PXR is localized to the midbrain VTA of rats. The role of PXR to influence 3α,5α-THP production from central biosynthesis, and/or metabolism of peripheral P(4), in the VTA, as well as its role to facilitate, or be increased by, affective/social behaviors is under investigation. Investigating novel behavioral functions of 3α,5α-THP extends our knowledge of the neurobiology of progestogens, relevant for affective/social behaviors, and their connections to systems that regulate affect and motivated processes, such as those important for stress regulation and neuropsychiatric disorders (anxiety, depression, schizophrenia, drug dependence). Thus, further understanding of 3α,5α-THP's role and mechanisms to enhance affective and motivated processes is essential.

Reduced metabolism in brain "control networks" following cocaine-cues exposure in female cocaine abusers

Objective

Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved.

Method

To test this we compared brain metabolism (using PET and ¹⁸FDG) between female (n = 10) and male (n = 16) active cocaine abusers when they watched a neutral video (nature scenes) versus a cocaine-cues video.

Results

Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05); females significantly decreased metabolism (−8.6%±10) whereas males tended to increase it (+5.5%±18). SPM analysis (Cocaine-cues vs Neutral) in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001) whereas males showed increases in right inferior frontal gyrus (BA 44/45) (only at p<0.005). The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001) in frontal (BA 8, 9, 10), anterior cingulate (BA 24, 32), posterior cingulate (BA 23, 31), inferior parietal (BA 40) and thalamus (dorsomedial nucleus).

Conclusions

Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from “control networks” (prefrontal, cingulate, inferior parietal, thalamus) in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition). This highlights the importance of gender tailored interventions for cocaine addiction.

Prenatal Stress Alters Progestogens to Mediate Susceptibility to Sex-Typical, Stress-Sensitive Disorders, such as Drug Abuse: A Review

Maternal-offspring interactions begin prior to birth. Experiences of the mother during gestation play a powerful role in determining the developmental programming of the central nervous system. In particular, stress during gestation alters developmental programming of the offspring resulting in susceptibility to sex-typical and stress-sensitive neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. However, neither these effects, nor the underlying mechanisms, are well understood. Our hypothesis is that allopregnanolone, during gestation, plays a particularly vital role in mitigating effects of stress on the developing fetus and may mediate, in part, alterations apparent throughout the lifespan. Specifically, altered balance between glucocorticoids and progestogens during critical periods of development (stemming from psychological, immunological, and/or endocrinological stressors during gestation) may permanently influence behavior, brain morphology, and/or neuroendocrine-sensitive processes. 5α-reduced progestogens are integral in the developmental programming of sex-typical, stress-sensitive, and/or disorder-relevant phenotypes. Prenatal stress (PNS) may alter these responses and dysregulate allopregnanolone and its normative effects on stress axis function. As an example of a neurodevelopmental, neuropsychiatric, and/or neurodegenerative process, this review focuses on responsiveness to drugs of abuse, which is sensitive to PNS and progestogen milieu. This review explores the notion that allopregnanolone may effect, or be influenced by, PNS, with consequences for neurodevelopmental-, neuropsychiatric-, and/or neurodegenerative- relevant processes, such as addiction.