Involvement of the Bed Nucleus of the Stria Terminalis and Its Input from the Ventral Subiculum in Formation of Fear Memory

• Main Authors: Tzu-Lan Liu, 劉姿蘭
• Other Authors: 梁庚辰
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/64287085456556272145

博士 === 國立臺灣大學 === 心理學研究所 === 101 === This thesis addressed a issue of whether activating the glutamatergic fibers from the ventral subiculum (vSUB) to the bed nucleus of the stria terminalis (BNST) may affect formation and retrieval of fear memory through activating noradrenergic fibers innervating the BNST. The issue was examined by pharmacological manipulation and unit recording in behaving rats. Male Wistar rats were trained on an inhibitory avoidance or contextual fear conditioning task and immediate after training received drug infusion into the vSUB or BNST via indwelling cannulae. Results indicated that posttraining intra-vSUB infusion of scopolamine or oxotremorine impaired or enhanced retention in both tasks, while various drugs infused in the vSUB or BNST shortly before a memory test did not affect retention. Moreover, in each task memory effects of cholinergic manipulation of the vSUB were blocked by altering the BNST glutamatergic or noradrenergic functions. Thus, the vSUB and BNST interacted to affect formation of fear memory, presumably the classical conditioning component. The single unit recording data indicated that rats with more responsive units altering their activity after learning had better retention performance in subsequent retention tests. Moreover, the deactivated response in the first, but not 2nd to 4th hours, after training significantly correlated with subsequent retention, suggesting that the BNST unit deactivation after learning may be critical for memory formation. Posttraining intra-vSUB infusion of a memory-impairing dose of scopolamine altered the BNST neuronal activity by changing the activity patterns and delaying the time of activity change. Posttraining intra-vSUB infusion of a memory enhancing dose of oxotremorine did not induce significant changes of BNST unit activity that well correlated with behavior. In conclusion, our results revealed that the vSUB was involved in memory consolidation processing through interacting with the BNST.