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. 相似文献
Abstract - The ability of human fetuses to recognize their own mother's voice was examined. Sixty term fetuses were assigned to one of two conditions during which they were exposed to a tape recording of their mother or a female stranger reading a passage. Voice stimuli were delivered through a loudspeaker held approximately 10 cm above the maternal abdomen and played at an average of 95 dB SPL. Each condition consisted of three 2-min periods: no stimulus, voice (mother or stranger), and no stimulus. Fetal heart rate increased in response to the mother's voice and decreased in response to the stranger's; both responses were sustained for 4 min. The finding of differential behavior in response to a familiar versus a novel voice provides evidence that experience influences fetal voice processing. It supports an epigenetic model of speech perception, presuming an interaction between genetic expression of neural development and species-specific experience. 相似文献
Compared with their non-migrant peers, migrant children in China face major risks and challenges that may cause them to develop behavioral and psychological problems. Nevertheless, research has seldom addressed their victimization by bullies and its association with their mental health outcomes, much less the roles of intrapersonal and interpersonal sources of resilience in that relationship. In response, this study was designed to examine how bullying victimization both directly and indirectly influences migrant children’s mental health through intrapersonal and interpersonal sources of resilience. Data were collected from a school-based multistage random sample of 1,132 migrant children in Grades 4–9 (mean age = 11.88 years, range = 8–17 years; boys = 55.6%) attending public schools in Nanjing and private schools in Guangzhou, China. Structural equation modeling performed with Amos 25.0 revealed that both intrapersonal and interpersonal sources of resilience mediated the effect of bullying victimization on migrant children’s mental health, albeit intrapersonal sources demonstrated a slightly stronger mediation effect. The results thus suggest that social workers and educators should provide effective prevention and intervention strategies that promote intrapersonal and interpersonal sources of resilience among migrant children in China.