Effects of MDMA administration on scopolamine-induced disruptions of learning and performance in rats.

Functional deficits following short-course high-dose administration of 3,4-methylenedioxymethamphetamine (MDMA) have been difficult to characterize despite evidence indicating that MDMA is neurotoxic in several species. Therefore, the present research used rats trained to respond under a complex behavioral procedure (i.e., a multiple schedule of repeated acquisition and performance of response chains), pharmacological challenge with scopolamine and neurotransmitter assays to examine the effects of MDMA neurotoxicity on learning. Prior to MDMA administration, 0.032-0.32 mg/kg of scopolamine produced dose-dependent rate-decreasing and error-increasing effects in both components of the multiple schedule. Administration of 10 mg/kg of MDMA twice per day for 4 days also produced rate-decreasing and error-increasing effects on these days, but responding returned to baseline levels several days after the final injection. In contrast to the recovery of responding, this regimen of MDMA in untrained rats significantly reduced levels of both serotonin and its major metabolite, 5-hydroxyindoleacetic acid (5-HIAA), for 13-14 days. Furthermore, the rate-decreasing and error-increasing effects of scopolamine were significantly attenuated after MDMA treatment. These results indicate that certain complex operant behaviors rapidly recover from the effects of short-course high-dose MDMA administration, despite the reduced levels of serotonin in the central nervous system (CNS), and that this MDMA-induced loss of serotonin may affect cholinergic transmission.

Prolactin and testosterone affect seasonal differences in male meadow vole, microtus pennsylvanicus, odor preferences for female conspecifics.

Studies on nonseasonally breeding males have demonstrated that high titers of testosterone (T) stimulate reproduction, whereas high titers of prolactin (PRL) inhibit it. Recent evidence, however, suggests that for seasonally breeding males high titers of both PRL and T stimulate behaviors that support reproduction and mating. Thus, we hypothesized that high titers of both PRL and T are necessary and sufficient for male meadow voles to show a preference for the odor of long-photoperiod (LP) females. We tested this hypothesis by treating castrated LP males with bromocriptine and/or T, and by treating castrated short-photoperiod (SP) males with PRL and/or T. The data showed that high titers of both PRL and T are necessary for LP male meadow voles to maintain a preference for the odor of LP female meadow voles, but high titers of both hormones are not sufficient to induce SP males to show such a preference. Only SP males with high T and low PRL titers showed preferences for LP female odors. Interestingly. SP males with high PRL and high T titers preferred the odor of LP males, and SP males with high PRL and low T titers preferred the odors of SP females. The apparent contradictory effects of PRL and T in SP males suggest that the hormonal control of seasonal differences of male odor preferences may be more complex than previously believed.

Contact tracing to identify human immunodeficiency virus infection in a rural community.

This report describes a contact investigation conducted in rural South Carolina to identify, counsel, and educate persons infected with or exposed to the human immunodeficiency virus (HIV). Starting with one HIV antibody-positive man and his 19 sex contacts, we identified 83 sex contacts of HIV antibody-positive men. Of these, 64 were residents of the county and 63 (98%) agreed to be tested for evidence of HIV infection. Eight (13%) were HIV antibody positive. Thirty-six initially HIV antibody-negative men were reevaluated at a six-month follow-up visit, and three had seroconverted during this time. Of 25 men who reported practicing anal receptive intercourse, 13 (52%) were HIV antibody positive vs none of 43 men who reported strictly anal insertive intercourse. Comparing reported numbers of sexual contacts for the six-month periods before and after our initial investigation, the mean numbers of named sex contacts decreased by 82% for antibody-positive men and 54% for antibody-negative men. None of the men reported using condoms before entering the study; at the six-month follow-up visit, four (80%) of five of the antibody-positive men and 25 (69%) of 36 of the antibody-negative men reported using condoms at least some of the time.

KIE: A report is provided of a contact investigation conducted in rural South Carolina to identify, counsel, and educate men infected with or exposed to the human immunodeficiency virus (HIV). Valuable information was gained about the demographic patterns of persons at risk for HIV in the community studied, and data from the investigation suggest that, at least in the short term, significant behavior change takes place as a result of highly-directed counseling of the high-risk persons identified. Contact tracing in this instance proved relatively cost-effective despite the large amount of professional time devoted to patient counseling. The authors believe that the obvious benefits of direct contact tracing far outweigh the remote risk that confidentiality may be breached.