Shibata K, Furukawa T
Research Laboratory of Biodynamics, Fukuoka University, Japan.
Brain Res. 1988 Mar 8;443(1-2):117-24. doi: 10.1016/0006-8993(88)91604-6.
Sites of action of neurotensin (NT) in passive avoidance behavior were investigated by intracerebral injection in male Wistar rats, which were trained in a step-down type one-trial learning passive avoidance test. An unavoidable foot shock was delivered through the grid floor of a dark compartment (learning trial) and passive avoidance latencies were tested 24 h after the learning trial (retention test). NT at small doses, 0.2 and 0.5 microgram, injected into the mammillary body increased the latency of the retention test in passive avoidance behavior, without affecting locomotor activity or rectal temperature. However, NT injected into the central amygdaloid nucleus did not influence either passive avoidance behavior or rectal temperature. When injected into the preoptic area, the nucleus accumbens or the substantia nigra, NT did not alter the passive avoidance behavior either. Responsiveness to electric foot shock was reduced after injection of NT into the mammillary body. Thus, the change in the responsiveness to electric foot shock did not comply with that in the passive avoidance behavior following intramammillary body injection of NT. These results suggest that the mammillary body is a site of action of NT in passive avoidance behavior and may play an important role in learning the behavior.
通过对雄性Wistar大鼠进行脑内注射，研究了神经降压素（NT）在被动回避行为中的作用位点。这些大鼠在一步式单次学习被动回避试验中接受训练。在黑暗隔室的网格地板上施加不可避免的足部电击（学习试验），并在学习试验24小时后测试被动回避潜伏期（保持试验）。向乳头体注射小剂量（0.2和0.5微克）的NT可增加被动回避行为中保持试验的潜伏期，而不影响运动活动或直肠温度。然而，向中央杏仁核注射NT既不影响被动回避行为，也不影响直肠温度。当注射到视前区、伏隔核或黑质时，NT也不会改变被动回避行为。向乳头体注射NT后，对足部电击的反应性降低。因此，对足部电击的反应性变化与乳头体注射NT后被动回避行为的变化不一致。这些结果表明，乳头体是NT在被动回避行为中的作用位点，可能在学习该行为中起重要作用。
