Minority mating advantage of certain eye color mutants ofDrosophila melanogaster. III. Female discrimination and genetic background

A repetition of certain experiments done 2 years previously with two eye color mutants,brown andscarlet, inDrosophila melanogaster was undertaken to reconfirm results; however, initial tests revealed that strains or conditions had changed so that females were less discriminating. Testing was undertaken with changes in genetic background and certain laboratory conditions, with single females courted by equal numbers of two eye color types of males (3 red,R: 3 orange,O). These eye colors were produced as (1) mutants off the shelf, (2) recombinants from an outcross to a wild-type strain (CS), (3) mutants as in Experiment 1 but with male types stored either together or separately, and (4) recombinants from a double outcross of flies from Experiment 2 to hybrids from two additional wild strains,LS andOR. Experiment 4 producedR andO males that courted nearly equally (as in previous experiments), in contrast with about 70% courtship byR males in the other experiments. Females discriminated in favor of those second to court in G₀, G₁, and a repeat of G₀; however, with two generations of inbreeding, discrimination by this criterion lessened to become nonsignificant. In Experiments 1 and 2,O females favored second-courting males, butR females in hose experiments and all females in Experiment 3 mated more randomly. Effects of storing males either together or separately were not significant. About 20–30% of the females (low threshold) were highly receptive immediately after first courtship. Those trials plus any in which only a single type of male courted were omitted from estimations of female discrimination; a possible bias incurred by such omission against females that might have initial preferences was found to be nonsignificant. Discriminating ability was discussed as a fitness property inDrosophila populations.This research was supported in part by National Science Foundation Grant DEB 79-03259.     

Free choice ethanol intake of laboratory rats under different social conditions

To study the effects of different kinds of social deprivation on voluntary ethanol (ETOH) intake male Wistar rats were housed by (a) individual caging, (b) contact caging (partial social deprivation), and (c) group caging (four individuals per cage). In the latter condition the individuals were separated once a week from each other for 24 h. The rats simultaneously received water 5%, 10% and 20% ETOH for a period of 14 weeks. Additional control animals received water. Isolated individuals drank significantly more alcohol than group-housed or contact-caged rats. After a few days they preferred the 20% solution. Circadian measures revealed a discontinuous intake of high doses (> 0.5 g/kg/h) during short time periods. Contact-caged rats consumed much less ETOH, but both the preference for 20% ETOH and the circadian course of intake were similar to those occurring after isolation. ETOH intake of group-housed individuals was low. These individuals preferred the 5% solution and continuously consumed small ETOH doses. During the period of short-term isolation they drank even more ETOH than long-term isolated individuals. In contrast to the latter, the enhancement of intake decreased after some weeks. It is suggested that the differences between the housing groups not only reflect different degrees of isolation stress, but may also be explained by a contribution of different reinforcing or aversive psychotropic effects of ETOH. Reduction of isolation stress is probably most important in the situation of short term separation, whereas dose-dependent reinforcement via social stimulation or sedation may affect the drug taking behavior under the other social conditions.     

多动行为偏异儿童血5-羟色胺测定及其意义

目的　探讨心理卫生偏异 (简称行为异常 )多动行为偏异儿童 (简称多动 )与正常儿童血 5 -羟色胺 (5 -HT)含量差别。方法　用Achenbach儿童行为量表筛查并根据因子分分类对 30例行为异常儿童进行血 5 -HT含量测定 ,与 30例正常儿童对照组比较。结果　行为异常组血 5 -HT含量与正常组比较 ,无显著差异。而多动组与正常组比较 ,有显著差异 (P <0 .0 5 )。内向型因子组与正常组比较 ,有显著差异 (P <0 .0 5 )。结论　多动行为偏异儿童血 5 -HT含量明显降低 ,心理卫生偏异内向型组血 5 -HT含量明显升高。     

Behavioral significance of phasic changes in mesolimbic dopamine-dependent electrochemical signal associated with heroin self-injections

Summary High-speed chronoamperometry with monoamine-selective carbon fiber electrodes was used in rats to monitor, during 5–6 consecutive daily sessions, changes in DA-dependent electrochemical signal in the nucleus accumbens (NAcc) during intravenous heroin (0.1 mg/kg) self-administration (SA) behavior and passive repeated drug injections performed with a temporal scheme similar to that in the SA experiment. In trained animals, biphasic signal fluctuations time-locked to the individual lever-presses were found to accompany all but the first daily SAs. The signal gradually increased by 30–40 nM for the 10 minutes preceding the SA, reached a peak at the moment of lever-press and decreased abruptly by 40 nM for 3–4 min after heroin SA. The cycle then repeated, reaching a new peak at the moment of the next lever-press. Rapid bi-directional fluctuations in signal associated with individual heroin SAs were superimposed on substantial tonic increase in signal baseline (400–500 nM). This increase quickly developed after presentation of heroin-related light cue and the first SA, was relatively stable during all subsequent SAs and decreased towards the baseline after the last SA of a session. Changes in signal baseline induced by repeated heroin SAs depended strongly upon the signal's basal level (r=– 0.787); that signal preferentially increased when its basal values were low (0–300 nM), and decreased when signal was tonically elevated (> 600 nM). Repeated passive heroin injections also induced biphasic signal fluctuations and a similar tonic increase in signal baseline. Although a transient signal decrease (25 nM for 2–4 minutes) followed by a prolonged signal increase occurred after each but not the first passive injection, the gradual pre-injection signal acceleration was absent.Although DOPAC, a principal DA metabolite, may significantly contribute to the tonic increase in electrochemical signal seen during SA session, the changes in extracellular DA may be the main contributor to both the rapid signal increases preceding drug-taking and the transient signal decreases following heroin SA. If so, the present findings suggest that activation of mesolimbic DA cells and increase in DA transmission may be involved in the mediation of motivational and/or activational components of drug-seeking and drug-taking behavior. An acute termination of previous drug- and behavior-associated DA activation with a transient inhibition of DA release, immediately following heroin SA may correlate with the drug's rewarding action, representing a part of a mechanism regulating drug-taking behavior.     

Sleep problems and daytime behavior in childhood idiopathic epilepsy

PURPOSE: To evaluate the presence of sleep problems and their association with behavioral and adjustment problems in children with idiopathic epilepsy. METHODS: A parental questionnaire was used to assess sleep problems in 89 children with idiopathic epilepsy for comparisons with 49 siblings and 321 healthy control children, equally distributed for age and sex. Sleep problems were clustered into five factors: parasomnias, parent/child interaction during the night, sleep fragmentation, daytime drowsiness, and bedtime difficulties. Daytime behavior and psychological adjustment were assessed by means of the Child Behavior Checklist. Maternal distress and disturbance was evaluated by the Malaise Inventory. The better to identify factors associated with sleep problems in the children with epilepsy, multiple regression analysis was performed. RESULTS: Children with epilepsy showed significantly more sleep problems than did both siblings and healthy controls. Within the epileptic group, children with current seizures complained more of sleep problems than did the seizure-free children. Moreover, children with epilepsy showed more behavioral problems and maladjustment. Age, paroxysmal activity density, duration of illness, seizure frequency, and behavioral problems were significantly associated with sleep problems in the epileptic group. CONCLUSIONS: The results of this study in a highly selected sample pointed out the presence of sleep problems, and adjustment and behavioral problems in children with idiopathic epilepsy. The presence of epilepsy, although benign, in childhood is associated with adaptive problems of the child. From this point of view, the alteration of some sleep habits may be a sign of emotional maladjustment. Although parents failed to perceive them as a problem, our findings indicate that attention to sleep and behavioral problems is important in clinical management of children with idiopathic epilepsy.     

Modification of sexual behavior of Long-Evans male rats by drugs acting on the 5-HT1A receptor

Modulation of the sexual behavior of male rats by the anxiolytic buspirone (S-20499) and its analog gepirone were compared to the effects of 8-OH-DPAT (or DPAT, a selective 5-HT1A reference agonist), and BMY-7378 (a selective 5-HT1A partial agonist). Long-Evans rats were used; modulation of copulatory behavior and alteration of penile reflexes were examined. Modulation of copulatory behavior was assessed by three indices: frequency and length of intromission, and latency of ejaculation. DPAT, at doses of 1-8 mg/kg, reduced these three indices in a time dependent manner such that the effects peaked at 45 min and normalized at 90 min. The dose-effect relationship (assessed 45 min after DPAT injection) is bell-shaped with an ED50 approximately 1 mg/kg on the ascending limb of the curve. The effects of buspirone (2 mg/kg) and gepirone (2 mg/kg) on copulatory behavior were indistinguishable from control. BMY-7378 alone and in combination with these other 5-HT1A agonists reduced copulatory behavior, though not statistically significant. Penile reflexes, including number of erections, cups and flips, were inhibited by these agents: DPAT>buspirone>gepirone (inactive at 2 mg/kg). Furthermore, the latency period to erection was at least doubled by DPAT (2 mg/kg). Buspirone and gepirone, however, reduced the latency period to erection. BMY-7378 inhibited penile reflexes when administered alone and even more in combination with DPAT or buspirone. Two butyrophenone analogs, spiperone (a 5-HT1A and dopamine D2 antagonist) and haloperidol (a D2 antagonist), were also tested for their interaction with DPAT. Both of these drugs (at 0.25 mg/kg, 60 min after administration) reduced all indices of penile reflexes and copulation. Furthermore, in combination with DPAT (2 mg/kg, 45 min), the effects were synergistic such that sexual activity came nearly to a standstill. These opposing effects on putatively brain originated copulatory behavior and spinal mediated penile reflexes indicate that the effects of buspirone and DPAT on sexual behavior in the male rat may be possible at different parts of the central nervous system. If a tentative shared target site by DPAT and buspirone is the 5-HT1A receptor, than the same 5-HT receptor sub-type at different locations (brain, raphe nuclei, spinal cord and autonomic ganglia) may modulate rat sexual behavior in opposing ways.     

Interactive technology applications for behavioral counseling: issues and opportunities for health care settings

CONTENT: This article discusses the rationale for, and the potential benefits and limitations of, computer-based interactive health communication (IHC) programs for health behavior counseling. We describe common barriers to health behavior counseling in medical settings and show how IHCs can address these issues. Following an overview of current and likely near-future IHCs, the potential impact of IHCs on the patient-provider relationship is considered. Results from evaluations of IHCs are summarized and important and unique issues in evaluating IHCs are discussed. We conclude with recommendations for clinical applications, including recommendations for consumers considering purchase or adoption of IHCs and recommendations for future research.