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.     

LYING PERSON-TO-PERSON ABOUT LIFE EVENTS: A COGNITIVE FRAMEWORK FOR LIE DETECTION

Undetected lies of prospective or current employees cost business billions of dollars annually. The ability to detect these lies would be of immense benefit. Several recent reports have called for research on new, theoretically based methods of lie detection. In response, we tested the Activation-Decision-Construction Model of lying ( Walczyk, Roper, Seeman, & Humphreys, 2003 ) according to which response time is a cue to deception. Participants were tested person-to-person. In Experiment 1, half lied to questions probing recent episodic memories. The other half answered honestly. Liar-truth teller response time differences were observed between subjects. Discriminant analyses demonstrated the value of response time for uncovering deceit. Those highest in social skills were the quickest liars. In Experiment 2, lying was shown to take longer than truth telling within subjects, and within-subject response time standard deviations were shown to be converging cues to deception. Based on these data and the ADCM, a Time-Restricted Integrity Confirmation (Tri-Con) framework for lie detection is proposed that might one day provide cost effective lie detection for business.