Intergenerational effects of cocaine on maternal aggressive behavior and brain oxytocin in rat dams.

Gestational cocaine treatment results in significantly increased maternal aggression towards an intruder by postpartum day six, while acute postpartum treatment dose dependently decreases maternal aggressive (MA) behavior. Both increased and decreased aggression in the cocaine-treated dams are correlated with either decreased or increased levels of oxytocin in the amygdala, respectively. The current study was an effort to determine whether the effect of gestational cocaine on maternal aggression is transient or would continue into the postpartum period; whether an intermittent cocaine treatment regimen, which incorporates gestational and postpartum intermittent cocaine treatment, would differ from chronic daily gestational treatment; and finally, whether next generation female offspring of cocaine-treated or control dams would have altered MA behavior and oxytocin system changes attributable to either prenatal drug exposure, rearing condition or both. We now report no increase in maternal aggression following chronic gestational treatment and significantly lower levels of aggression in intermittently treated dams on postpartum day eight, with no significant effects in either group on postpartum day 12. Young adult female offspring of the cocaine-treated and control dams, who reared their own natural litters and were tested on postpartum day eight for maternal aggression, had higher levels of maternal aggression towards an intruder attributable to both prenatal cocaine exposure and rearing condition. Higher aggression in cocaine-reared next generation dams was associated with lower levels of oxytocin in the amygdala. Intergenerational effects of cocaine were apparent with respect to aggression and oxytocin system changes.

Impact of gestational cocaine treatment or prenatal cocaine exposure on early postpartum oxytocin mRNA levels and receptor binding in the rat.

Prior research reported decreased oxytocin levels in specific brain regions correlated with disruptions in maternal care following gestational cocaine treatment in rats. Similarly, prenatal exposure to cocaine impaired subsequent maternal behavior in adulthood, but behavioral alterations were not associated with decreases in oxytocin levels in the same brain regions as were found in their cocaine-treated rat dams. To determine if other aspects of the oxytocin system are disrupted by cocaine treatment or prenatal exposure to cocaine during critical time points associated with maternal care, oxytocin mRNA transcription and receptor binding were examined on postpartum day two in relevant brain regions following gestational treatment with, or prenatal exposure to, either cocaine or saline. We hypothesized that oxytocin mRNA levels and receptor binding would be differentially affected by cocaine in the early postpartum period of dams and their offspring. Our findings indicate that gestational cocaine treatment resulted in significant increases in oxytocin mRNA levels in only the paraventricular nucleus of cocaine-treated dams, with almost significant increases in both generations in the supraoptic nucleus, but no significant effects of cocaine on receptor binding in either generation of dams. These findings indicate that in addition to oxytocin levels, cocaine treatment or prenatal exposure primarily affects oxytocin mRNA synthesis, with little effect on receptor binding in specific brain regions associated with maternal behavior in the early postpartum period of the rat.

Gestational ethanol and nicotine exposure: effects on maternal behavior, oxytocin, and offspring ethanol intake in the rat.

Alcohol consumption and smoking during pregnancy is common, despite the known adverse effects of these drugs on fetal development. Though studies on the effects of each drug separately are published, little is known about the effect of concurrent use of alcohol and nicotine in humans or in preclinical models. In this report, we examined the impact of continuous gestational exposure to both ethanol via liquid diet and nicotine via an osmotic minipump on maternal behavior, offspring ethanol intake, and oxytocin levels in a rat model. Dams were tested for the onset of maternal behavior with litters of unexposed surrogate pups and then killed to examine oxytocin levels within specific brain regions. Drug-exposed offspring reared by surrogate dams were tested for ethanol intake at either adolescence or adulthood, and oxytocin levels were measured in relevant brain regions after behavioral tests. Dams exhibited minor deficits in maternal care, which were associated with lower oxytocin levels in both the ventral tegmental and medial preoptic areas compared to control dams. Prenatal exposure altered sex-specific ethanol intake, with differential effects at adolescence and adulthood. Oxytocin system changes were also apparent in the ventral tegmental and medial preoptic regions of drug-exposed adolescent and adult offspring. These results suggest that dam treatment with ethanol and nicotine can somewhat negatively affect the early rearing environment, and that prenatal exposure to both of these drugs results in drinking behavior differing from what would be expected from either drug alone. Oxytocin's possible involvement in the mediation of these effects is highlighted.

Orbitofrontal cortex reflects changes in response-outcome contingencies during probabilistic reversal learning.

In a continuously changing environment, in which behavioral outcomes are rarely certain, animals must be able to learn to integrate feedback from their choices over time and adapt to changing reward contingencies to maintain flexible behavior. The orbitofrontal region of prefrontal cortex (OFC) has been widely implicated as playing a role in the ability to flexibly control behavior. We used a probabilistic reversal learning task to measure rats' behavioral flexibility and its neural basis in the activity of single neurons in OFC. In this task, one lever, designated as 'correct', was rewarded at a high probability (80%) and a second, spatially distinct lever, designated as 'incorrect', was rewarded at a low probability (20%). Once rats reached a learning criterion for reliably selecting the correct lever, reward contingencies of the two levers were switched, and daily sessions were conducted until rats reliably selected the new correct lever. All rats performed the initial Acquisition and subsequent Reversal successfully, with more sessions needed to learn the Reversal. OFC neurons were recorded during five behavioral sessions spanning Acquisition and Reversal learning. The dominant pattern of neural responding in OFC, identified by principal component analysis of the population of neurons recorded, was modulated by reward outcome across behavioral sessions. Generally, activity was higher following rewarded choices than unrewarded. However, there was a correlation between reduced responses to reward following incorrect choices and the establishment of the preference for the correct lever. These results show how signaling by individual OFC neurons may participate in the flexible adaptation of behavior under changing reward contingencies.

Cocaine treatment alters oxytocin receptor binding but not mRNA production in postpartum rat dams.

Gestational cocaine treatment in rat dams results in decreased oxytocin (OT) levels, up-regulated oxytocin receptor (OTR) binding density and decreased receptor affinity in the whole amygdala, all concomitant with a significant increase in maternal aggression on postpartum day six. Rat dams with no gestational drug treatment that received an infusion of an OT antagonist directly into the central nucleus of the amygdala (CeA) exhibited similarly high levels of maternal aggression towards intruders. Additionally, studies indicate that decreased OT release from the hypothalamic division of the paraventricular nucleus (PVN) is coincident with heightened maternal aggression in rats. Thus, it appears that cocaine-induced alterations in OT system dynamics (levels, receptors, production, and/or release) may mediate heightened maternal aggression following cocaine treatment, but the exact mechanisms through which cocaine impacts the OT system have not yet been determined. Based on previous studies, we hypothesized that two likely mechanisms of cocaine's action would be, increased OTR binding specifically in the CeA, and decreased OT mRNA production in the PVN. Autoradiography and in situ hybridization assays were performed on targeted nuclei in brain regions of rat dams on postpartum day six, following gestational treatment twice daily with cocaine (15 mg/kg) or normal saline (1 ml/kg). We now report cocaine-induced reductions in OTR binding density in the ventromedial hypothalamus (VMH) and bed nucleus of the stria terminalis (BNST), but not the CeA. There was no significant change in OT mRNA production in the PVN following cocaine treatment.

Assays for genetic dissection of septin filament assembly in yeast, from de novo folding through polymerization.

In Saccharomyces cerevisiae, septin mutations have severe effects on colony-forming ability, particularly at high temperatures, allowing the full variety of genetic tools available in this model organism to be applied to the study of septin biology. Although many details of septin function remain unknown, one can exploit a small number of easily scored phenotypes-proliferation capacity, cell morphology, septin localization, and septin ring integrity-as sensitive readouts of properly assembled septin filaments. Accordingly, this chapter focuses on genetic approaches targeted toward understanding the molecular mechanisms of de novo septin folding, heterooligomerization, and polymerization into filaments. The same general methods can be used to interrogate septin function, although interpretation of results can be more complicated. As genetic-based methodologies are technically simple but particularly dependent on interpretation, here I focus on the logic underlying the most common interpretations of results using septin mutants.

Small molecule perturbations of septins.

Progress on the study of the molecular and cellular biology of septins would be greatly accelerated by the development of small molecules that directly inhibit higher-order septin assembly in vivo. By comparison, molecules like latrunculin, paclitaxil, benomyl, etc. allow researchers to acutely perturb the actin or tubulin cytoskeletal networks. Two small molecules, forchlorfenuron (FCF; N-(2-chloro-4pyridyl)-N-phenylurea) and 1-ethyl-3-(4-methoxyphenyl)-6-methylpyrimido[5,4-e][1,2,4]triazine-5,7-dione (PubChem CID 906558), have documented effects on septin localization and/or function, although for each molecule there is also strong evidence for off-target effects. In this chapter we provide a summary of ways to utilize FCF to alter higher-order septin assembly properties in living cells.

Molecular recognition in the HIV-1 capsid/cyclophilin A complex.

The HIV-1 capsid protein (CA) makes an essential interaction with the human peptidyl prolyl isomerase, cyclophilin A (CypA), that results in packaging of CypA into the virion at a CA to CypA stoichiometry of approximately 10:1. The 231 amino acid residue capsid protein is composed of an amino-terminal CypA binding domain (1 to approximately 151; CA151) and a carboxyl-terminal dimerization domain (approximately 151 to 231). We find that CypA binds dimeric CA and monomeric CA151 with identical intrinsic affinities (K[d] = 16(+/-4) microM). This result demonstrates that capsid dimerization and cyclophilin A binding are not thermodynamically coupled and suggests that the substoichiometric ratio of CypA in the HIV-1 virion results from the intrinsic stability of the CA/CypA complex. In the known co-crystal structure of the CA151/CypA complex, CypA binding is mediated exclusively by an exposed capsid loop that spans residues Pro85 to Pro93. The energetic contributions to CypA binding were quantified for each residue in this loop, and the results demonstrate that the Gly89-Pro90 dipeptide is the primary cyclophilin A recognition motif, with Pro85, Val86, His87, Ala88, and Pro93 also making energetically favorable contacts. These studies reveal that the active site of CypA, which can catalyze the isomerization of proline residues in vitro, also functions as a sequence-specific, protein-binding motif in HIV-1 replication.

The effects of dopaminergic/serotonergic reuptake inhibition on maternal behavior, maternal aggression, and oxytocin in the rat.

Studies using dopaminergic and serotonergic agonists or antagonists implicate involvement of these systems in various aspects of early maternal behavior and postpartum aggression towards an intruder in rats, both of which are associated with the presence of oxytocin in specific brain regions. It is unclear however, if or how long-term uptake inhibition of either neurotransmitter system alone or in combination, affects oxytocin system dynamics or maternal behavior/aggression. Pregnant women frequently take drugs (antidepressants, cocaine) that induce long-term reuptake inhibition of dopamine and/or serotonin, thus it is important to understand these effects on behavior and biochemistry. Rat dams were treated throughout gestation with amfonelic acid, fluoxetine, or a combination of both, to investigate effects of reuptake inhibition of dopamine and serotonin systems respectively, on maternal behavior, aggression and oxytocin. The more appetitive aspects of maternal behavior (nesting, licking, touching) and activity were increased by the low dose of amfonelic acid, high dose of fluoxetine, or the high dose combination more than other treatments. Aggression was decreased by amfonelic acid and somewhat increased by fluoxetine. Dopamine uptake inhibition appears to have a strong effect on hippocampal oxytocin levels, while receptor dynamics may be more strongly affected by serotonin uptake inhibition.

Dopamine D2/3 receptor antagonism reduces activity-based anorexia.

Anorexia nervosa (AN) is an eating disorder characterized by severe hypophagia and weight loss, and an intense fear of weight gain. Activity-based anorexia (ABA) refers to the weight loss, hypophagia and paradoxical hyperactivity that develops in rodents exposed to running wheels and restricted food access, and provides a model for aspects of AN. The atypical antipsychotic olanzapine was recently shown to reduce both AN symptoms and ABA. We examined which component of the complex pharmacological profile of olanzapine reduces ABA. Mice received 5-HT(2A/2C), 5-HT3, dopamine D1-like, D2, D3 or D2/3 antagonist treatment, and were assessed for food intake, body weight, wheel running and survival in ABA. D2/3 receptor antagonists eticlopride and amisulpride reduced weight loss and hypophagia, and increased survival during ABA. Furthermore, amisulpride produced larger reductions in weight loss and hypophagia than olanzapine. Treatment with either D3 receptor antagonist SB277011A or D2 receptor antagonist L-741,626 also increased survival. All the other treatments either had no effect or worsened ABA. Overall, selective antagonism of D2 and/or D3 receptors robustly reduces ABA. Studies investigating the mechanisms by which D2 and/or D3 receptors regulate ABA, and the efficacy for D2/3 and/or D3 antagonists to treat AN, are warranted.

Early postpartum pup preference is altered by gestational cocaine treatment: associations with infant cues and oxytocin expression in the MPOA.

Cross-fostering studies suggest cocaine-induced deficits in maternal behavior could be associated with altered behavior of offspring following prenatal cocaine-exposure. Neonatal vocalizations are an important offspring cue facilitating early interactions between dam and rodent pup offspring and have been shown to be altered following prenatal cocaine-exposure. It is unclear how variations in acoustic parameters of USVs impact maternal behavior and the mechanism(s) underlying these processes. The present study examined differences in cocaine-exposed and control rodent dam maternal preference of cocaine-exposed or untreated pups in a dual choice apparatus. Relationship of preference-like behavior with pup USVs and dam oxytocin expression was explored. Gestational cocaine-exposure interfered with preference-like behavior of dams on postpartum day 1 with cocaine-exposure associated with decreased time spent on the cocaine-exposed pup side compared to the control pup side, and decreases in preference-like behavior associated in part with decreased number of USVs being emitted by cocaine-exposed pups. On postpartum day 5, decreased oxytocin expression in the medial preoptic area was associated with altered preference-like behavior in cocaine-exposed dams, including frequency and latency to touch/sniff pups. Results indicate cocaine's effects on the mother-infant relationship is likely synergistic, in that cocaine influences mother and offspring both independently and concertedly and that variations within pup vocalizations and the oxytocin system may be potential mechanism(s) underlying this synergistic relationship during the postpartum period.

Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate.

The response of 23 children with attention deficit disorder (ADD) with hyperactivity (+H) and 17 children with ADD without hyperactivity (-H) to three doses of methylphenidate (5, 10, and 15 mg twice a day) was evaluated in a triple-blind, placebo-controlled cross-over design using parent and teacher ratings of behavior, laboratory tests of ADD symptoms, and behavioral observations during academic performance. Results indicated that the children with ADD+H were rated as having more pervasive behavioral problems at home and more pervasive and severe conduct problems at school than the children with ADD-H. Laboratory tests found the children with ADD+H to be impaired in behavioral inhibition and vigilance whereas children with ADD-H were more impaired in the consistent retrieval of verbally learned material Drug effects were noted on the parent and teacher ratings and on most laboratory measures, with all three doses typically producing significant changes but rarely differing among themselves in effectiveness. The groups were not found to differ significantly on any measures in their response to methylphenidate. However, more children with ADD-H were clinically judged as having either no clinical response (24%) or responding best to the low dose (35%) of medication. In contrast, most ADD+H (95%) children were judged to be positive responders and most were recommended to receive the moderate to high dose (71%).

Side effects of methylphenidate in children with attention deficit hyperactivity disorder: a systemic, placebo-controlled evaluation.

The frequency and severity of 17 side effects presumably associated with stimulant medication were assessed during a rigorous, triple-blind, placebo-controlled, crossover evaluation of methylphenidate, 0.3 and 0.5 mg/kg twice a day, in 83 children with attention deficit hyperactivity disorder. Side effects were rated by parents and teachers at the end of each weekly drug condition. Three children (3.6%) had side effects that were sufficiently serious to warrant immediate discontinuation of medication. Parent ratings indicated that only the side effects of decreased appetite, insomnia, stomachaches, and headaches increased significantly in frequency and severity during the two active medication doses as compared with the placebo condition. Fewer than half of the children experienced these side effects and among those who did, ratings of mean severity remained in the mild range. Teacher ratings showed little change over drug conditions, except on ratings of staring, sadness, and anxiety, which declined with increasing dose of medication. Parent ratings indicated that only the side effects of decreased appetite, insomnia, stomachaches, and headaches increased significantly in frequency and severity during the two active medication doses as compared with the placebo condition. Fewer than half of the children experienced these side effects and among those who did, ratings of mean severity remained in the mild range. Teacher ratings showed little change over drug conditions, except on ratings of staring, sadness, and anxiety, which declined with increasing dose of medication. Surprisingly, a high frequency of these behavior side effects were reported during the placebo condition. Stimulant medication within this therapeutic range, therefore, results in few, generally mild side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of the development of female hamster behaviour by implants of testosterone and non-aromatizable androgens administered neonatally.

Testosterone in its free form, and dihydrotestosterone (DHT) and androsterone, both androgens which are not aromatizable to oestrogen, injected in oil during the neonatal period have been reported not to modify the development of female sexual behaviour. This failure might be due to the short period of activity of these substances when injected in liquid vehicles. In the current study, a Silastic pellet containing 9% of its weight of testosterone, androsterone, or DHT was implanted subcutaneously in 42 female and 38 neonatally castrated male hamsters on day 2 of life and removed on day 10. Pellets of pure Silastic were implanted in 36 control animals. Males were gonadectomized on day 5 and females on day 45. Female sexual behaviour induced by oestradiol benzoate and progesterone was measured in a series of 10-min mating tests with vigorous males, starting at 55 days of age. The duration of lordosis was consistently reduced below control levels in females implanted with testosterone, DHT, and androsterone, and in males, with testosterone and DHT. Thus the free form of testosterone, and some non-aromatizable androgens, when present for a sufficiently long period after birth, can permanently suppress development of female reproductive behaviour.

Response of children with ADHD to methylphenidate: interaction with internalizing symptoms.

OBJECTIVE: The purpose of this study was to examine differences in methylphenidate (MPH) response between groups of children with attention-deficit hyperactivity disorder (ADHD) who exhibited varying degrees of internalizing symptoms. METHOD: A sample of 40 children with ADHD was subdivided into three groups based on the severity of comorbid internalizing symptoms. Differential effects of three doses of MPH (5 mg, 10 mg, 15 mg) were evaluated in a double-blind, placebo-controlled fashion using multiple outcome measures across home, school, and clinic settings. RESULTS: Children with ADHD and comorbid internalizing symptoms were significantly less likely to respond positively to MPH than were their noninternalizing counterparts according to teacher ratings and behavioral observations during a clinic-based academic task. CONCLUSIONS: Children who exhibit comorbid symptoms of ADHD and internalizing disorder are less likely to respond to MPH in classroom settings and on academic tasks. A significant minority of children with comorbid conditions may be at a higher risk for an adverse medication response relative to patients with ADHD who are not exhibiting internalizing symptoms. Further research is necessary to delineate the characteristics of possible adverse responders.

The response of aggressive and nonaggressive ADHD children to two doses of methylphenidate.

Differences between 37 aggressive and 37 nonaggressive children with attention deficit hyperactivity disorder (ADHD) were evaluated as was their response to two doses of methylphenidate (0.3 and 0.5 mg/kg) using a multimethod battery of behavior ratings, laboratory tests, and direct observations. Aggressive ADHD children differed little from nonaggressive ADHD children except that nonaggressives displayed more problems with inattentiveness at school than aggressives while mothers of aggressives reported more symptoms of psychopathology in themselves than mothers of nonaggressives. In their drug responding, aggressives and nonaggressives were quite similar. The few exceptions were on measures of conduct, on which the aggressives were initially rated as more extreme and subsequently showed the greater degree of improvement from medication than nonaggressives. Results replicated those of a previous study and further indicate that aggressive and nonaggressive ADHD children share a common disorder of ADHD but aggressives have more impaired family situations.

Comprehensive evaluation of attention deficit disorder with and without hyperactivity as defined by research criteria.

Children with attention deficit disorder with hyperactivity (ADD+H; N = 48) were compared with those without hyperactivity (ADD-H; N = 42), as well as with learning disabled and control children, on an extensive battery of interviews, behavior ratings, tests, and direct observations. ADD+H children had more externalizing and internalizing symptoms by parent and teacher report, were more off task during vigilance testing, and had more substance abuse, ADD+H, and aggression among their relatives than did the other groups. ADD-H children were more day-dreamy and lethargic by teacher report, more impaired in perceptual-motor speed, and had more anxiety disorders among their relatives than did ADD+H children. Results indicate that these 2 types of ADD may be separate, distinct childhood disorders rather than subtypes of a common attention deficit.

The cytotoxic and cytostatic effects of the bitter melon (Momordica charantia) on human lymphocytes.

We have previously reported that a crude extract from the bitter melon (Momordica charantia) killed human leukemic lymphocytes in a dose-dependent manner while not affecting the viability of normal human lymphocyte cells at these same doses (Takemoto et al., 1980). We now report that the crude preparation has both cytostatic and cytotoxic activities which are heat stable and trypsin-sensitive. Time and dose-response curves suggest that the factors act quickly, perhaps by entry into the cell. The effects of the crude extract are complete after only 2 hr of exposure. These activities are not due to the presence of the lectins from bitter melon seeds, as these purified proteins had no activity against human lymphocytic cells.

Assessment of health status in peritoneal dialysis patients: a potential outcome measure.

OBJECTIVES: To determine the feasibility and practicality of measuring general health status (GHS) in an outpatient peritoneal dialysis population. To determine whether GSH correlated intuitively with biochemical, socio-demographic and co-morbidity measurements. DESIGN: The Medical Outcomes Study 20-item short form was administered on a voluntary basis in the outpatient setting. Demographic and current biochemical data were extracted from the medical record. The effects of the socio-demographic, biochemical and physiologic variables on the six subscales of GHS generated by the questionnaire were estimated using multivariate linear regression analysis resulting in the development of six separate models. SETTING: Peritoneal dialysis program of a University Hospital. PATIENTS: Sixty stable patients on home peritoneal dialysis completed the GHS questionnaire during regularly scheduled outpatient visits. Ages ranged from 13 to 81 years. The study group included 14 diabetics (23%). RESULTS: Administering the questionnaire caused no logistical difficulties in the outpatient setting. Regression models for predicting GHS were both significant and intuitively correct. The presence of co-morbidities such as diabetes mellitus (p = 0.002; Social Subscale) and peripheral vascular disease (p = 0.016: General Health Subscale) had the most significant negative impact on GHS. An increased length of time on dialysis was associated with a higher GHS (p = 0.002; Physical Subscale). CONCLUSION: General Health Status questionnaires can be readily administered to peritoneal dialysis patients in the outpatient setting. They have face validity as a measurement of wellness and functioning. The longitudinal use of such instruments in conjunction with clinical and laboratory findings may identify both medical and non-medical factors impacting on our peritoneal dialysis population.

The effect of dentures and denture adhesives on mouth alcohol retention.

A total of 24 alcohol-free, denture-wearing subjects were tested for mouth-alcohol retention times with an Intoxilyzer 5000. The subjects were given 30 mL doses of 80 proof brandy to swish in their mouths without swallowing for 2 min prior to expectorating the dose. Subjects were tested under three conditions: 1) with dentures removed, 2) with dentures held loosely in place without an adhesive, and 3) with dentures plus an adhesive. Beyond 20 min following expectoration, mouth alcohol made no significant contribution to the apparent breath alcohol concentration (BrAC), with trace (less than or equal to 0.01 g/210 L) readings found in only two of the subjects. Denture use, both with and without the concurrent use of adhesives does not significantly affect BrAC as long as a pretest alcohol deprivation period of 20 min is observed.