Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Preliminary efficacy of a computer-based HIV intervention for African-American women

This study evaluated the preliminary efficacy of a computer-based HIV intervention to enhance HIV-protective sexual behaviours, based on a randomised controlled trial among 135 African-American women, 21-29 years of age, seeking services at Planned Parenthood in Atlanta, GA. Participants were randomised either to a control session two, 60-minute computer-based HIV intervention sessions administered on a laptop computer that each concluded with a 15-minute small group session or to a control session of general health information including discussion on HIV prevention. Relative to controls, participants in the computer-based HIV intervention were more knowledgeable about HIV/STD prevention and reported higher scores on the measure of condom use self-efficacy at 3 months post-intervention; they also reported a higher percentage of condom-protected sex and were more likely to use condoms consistently for vaginal sex (odds ratio, OR = 5.9; p < 0.039) and were more likely to use condoms consistently for oral sex (OR = 13.83; p < 0.037). This relatively brief intervention provides preliminary support that an evidence-based group-based HIV prevention intervention for young African-American women can be adapted to a computer-based HIV intervention.