Wesierska Malgorzata, Adamska Iwona, Malinowska Monika
Department of Neurophysiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, Poland.
Neurobiol Learn Mem. 2009 Jan;91(1):41-9. doi: 10.1016/j.nlm.2008.09.005. Epub 2008 Oct 31.
Retrosplenial cortex (RSC) together with the hippocampus is a component of the spatial memory circuit. To elucidate the role of the RSC in spatial memory formation in the immediate presence of both relevant and irrelevant spatial stimuli, we used a new place avoidance task, in which rats learn to avoid shock in an unmarked place. In the present study, we manipulated the relevance of distal "Room" stimuli and local "Arena" stimuli for place avoidance. Rats with ibotenate lesions of RSC, control sham lesions (Csl) and intact control rats (Cint) initially learned the (Room&Arena)+ task variant in which both Room and Arena stimuli are relevant for defining the shock sector. Afterwards, different subsets of rats from each group were trained in the following task variants: (i) Room+Arena-, in which the arena continuously rotated so that Room stimuli were relevant and Arena stimuli were irrelevant for avoiding shock; (ii) Arena+, in which the arena and shock sector rotated in a dark room so that Arena stimuli were relevant and Room stimuli were irrelevant for avoiding shock; (iii) Room+, in which the arena was covered in shallow water so that only Room stimuli were relevant for avoiding the shock sector whether the arena was stationary or rotating. We found that damage of RSC impaired the Room+Arena- variant that required relevant and irrelevant stimuli to be segregated. Importantly, the same lesions spared task variants that did not require segregation. Our results suggest an involvement of retrosplenial cortex in the segregation of spatial information.
压后皮质（RSC）与海马体共同构成空间记忆回路的一个组成部分。为了阐明RSC在同时存在相关和不相关空间刺激的情况下对空间记忆形成的作用，我们采用了一种新的位置回避任务，即让大鼠学会在一个无标记的位置避免受到电击。在本研究中，我们操控了远端“房间”刺激和局部“实验场”刺激对位置回避的相关性。患有RSC鹅膏氨酸损伤的大鼠、对照假损伤大鼠（Csl）和完整对照大鼠（Cint）最初学习了（房间&实验场）+任务变体，其中房间和实验场刺激对于定义电击区域均相关。之后，每组的不同大鼠亚组接受了以下任务变体的训练：（i）房间+实验场-，其中实验场持续旋转，使得房间刺激对于避免电击相关，而实验场刺激不相关；（ii）实验场+，其中实验场和电击区域在暗室中旋转，使得实验场刺激对于避免电击相关，而房间刺激不相关；（iii）房间+，其中实验场被浅水覆盖，使得无论实验场是静止还是旋转，只有房间刺激对于避免电击区域相关。我们发现，RSC损伤损害了需要区分相关和不相关刺激的房间+实验场-变体。重要的是，相同的损伤对不需要区分的任务变体没有影响。我们的结果表明压后皮质参与了空间信息的区分。
