Nitz Douglas, McNaughton Bruce
Department of Neural Systems, Memory, and Aging, University of Arizona, Tucson, Arizona 85724, USA.
J Neurophysiol. 2004 Feb;91(2):863-72. doi: 10.1152/jn.00614.2003. Epub 2003 Oct 1.
Parallel recordings of hippocampal principal cells and interneurons were obtained as rats foraged in familiar and adjacent, novel environments. Firing rates of each cell type were assessed as a function of spatial location. Many CA1 interneurons exhibited large decreases in activity in the novel compared with the familiar environment. Dentate gyrus interneurons, however, were much more likely to exhibit large increases in firing in the novel environment. Neither effect was correlated with basic interneuron discharge properties such as degree of theta modulation, baseline firing rate or degree of spatially modulated discharge. Both CA1 and dentate gyrus interneuron rate changes extended into regions of the familiar environment bordering the novel environment. Principal cells in CA1 and dentate gyrus exhibited similar patterns of place specific activity each being indicative of incorporation of novel spatial information into the spatial representation of the familiar environment. The data indicate that inhibitory networks in the CA1 and dentate gyrus areas are modulated in a divergent fashion during the acquisition of novel spatial information and that interneuron activities can be used to detect those regions of an environment subject to redistribution of principal cell spatial activity patterns.
在大鼠于熟悉且相邻的新环境中觅食时，获取了海马体主细胞和中间神经元的并行记录。评估了每种细胞类型的放电频率作为空间位置的函数。与熟悉环境相比，许多CA1中间神经元在新环境中的活动大幅下降。然而，齿状回中间神经元在新环境中更有可能出现放电大幅增加的情况。这两种效应均与中间神经元的基本放电特性无关，如theta调制程度、基线放电频率或空间调制放电程度。CA1和齿状回中间神经元的放电频率变化都延伸到了与新环境相邻的熟悉环境区域。CA1和齿状回中的主细胞表现出相似的位置特异性活动模式，每种模式都表明新的空间信息被整合到了熟悉环境的空间表征中。数据表明，在获取新的空间信息过程中，CA1和齿状回区域的抑制性网络以不同的方式受到调制，并且中间神经元的活动可用于检测环境中主细胞空间活动模式发生重新分布的那些区域。
