Effects of Neonatal Footshock Stress on Glucocorticoid and 5- HT2A/2C Receptor Bindings and Exploratory Behavior

• 영문명: Effects of Neonatal Footshock Stress on Glucocorticoid and 5- HT_2A/2C Receptor Bindings and Exploratory Behavior
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Dong Goo Kim Seoul Lee Dong Won Kang Jong Su Lim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제2권 제6호, 677~685쪽, 전체 9쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1998.01.01

영문 초록

To investigate the effects of neonatal stress on behavior and neurochemistry, rats were exposed to the footshock stress on postnatal day (PND) 14 or PNDs 14 and 21. Rats were exposed to uncontrollable electric shocks delivered to the floor with a constant current (0.8 mA) for 5 sec period. Daily sessions consisted of 60 trials on a random time schedule with an average of 55 sec. The first exposure to footshocks on PND 14 decreased body weight gain for 1 day. However, the second exposure to footshocks on PND 21 did not affect body weight gain. Exploratory activity was measured by exposing a rat to a novel environment 24 h after experience of footshocks. Similar to the body weight changes, a decreased activity was noted after the first exposure to footshocks, while no changed activity was noted after the second exposure to footshocks. However, the Bmax value of 5-HT_2A/2C receptors in the cortex decreased by the second exposure to footshocks, but not by the first exposure to footshocks. Moreover, an autoradiographic study revealed that the density of [³H]dexamethasone binding in hippocampus decreased in rats exposed to footshocks 4 times during PND 14∼20. These results suggest that the uncontrollable footshock stress changes 5-hydroxytryptamine and glucocorticoid receptor systems acutely and that the repeated exposure to the same stress may not elicit behavioral alterations by the compensatory activity of young brain although changes in some neurochemistry exist.

키워드

Footshock Neonatal stress 5-Hydroxytryptamine Glucocorticoid Exploratory behavior