Shibata Hideshi, Yukie Masao
Department of Veterinary Anatomy, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Eur J Neurosci. 2003 Sep;18(6):1615-26. doi: 10.1046/j.1460-9568.2003.02868.x.
Previous functional studies suggest that the posterior cingulate gyrus is involved in spatial memory and its posteroventral part, in particular, is also involved in auditory memory. However, it is not clear whether the neural connections of the posteroventral part differ from those of the rest of the posterior cingulate gyrus. Here, we describe the thalamic connections of the posteroventral part of monkey area 23b (pv-area 23b), the main component of the posteroventral posterior cingulate gyrus. We compare these thalamic connections with those of the more dorsal area 23b (d-area 23b) and of adjoining retrosplenial areas 29 and 30. Thalamocortical projections to pv-area 23b originate mainly from the anterior nuclei, nucleus lateralis posterior and medial pulvinar. In contrast, projections to d-area 23b originate from the nucleus lateralis posterior, medial pulvinar, nucleus centralis latocellularis, mediodorsal nucleus and nucleus ventralis anterior and lateralis and weakly from the anterior nuclei. Projections to retrosplenial areas 29 and 30 originate from the anterior nuclei. Corticothalamic projections from pv-area 23b terminate in the anterior and laterodorsal nuclei, nucleus lateralis posterior and medial pulvinar. Projections from d-area 23b terminate in these nuclei as well as the nucleus ventralis anterior and lateralis. Projections from area 30 terminate mainly in the anterior nuclei and, to a lesser extent, in the medial pulvinar. These results show that the connections of pv-area 23b differ from those of d-area 23b or areas 29 and 30. This suggests that pv-area 23b may play distinct functional roles in memory processes, such as spatial and auditory memory.
以往的功能研究表明，后扣带回参与空间记忆，尤其是其后腹侧部分也参与听觉记忆。然而，后腹侧部分的神经连接是否与后扣带回其他部分不同尚不清楚。在此，我们描述了猴脑23b区后腹侧部分（pv-23b区）的丘脑连接，它是后扣带回后腹侧的主要组成部分。我们将这些丘脑连接与更靠背侧的23b区（d-23b区）以及相邻的压后皮质29区和30区的丘脑连接进行比较。丘脑皮质投射到pv-23b区主要起源于前核、后外侧核和内侧丘脑枕。相比之下，投射到d-23b区起源于后外侧核、内侧丘脑枕、外侧中央细胞群核、背内侧核以及腹前核和腹外侧核，从前核的投射较弱。投射到压后皮质29区和30区起源于前核。从pv-23b区发出的皮质丘脑投射终止于前核、外侧背核、后外侧核和内侧丘脑枕。从d-23b区发出的投射终止于这些核以及腹前核和腹外侧核。从30区发出的投射主要终止于前核，在较小程度上终止于内侧丘脑枕。这些结果表明，pv-23b区的连接与d-23b区或29区和30区不同。这表明pv-23b区可能在记忆过程中，如空间和听觉记忆中发挥独特的功能作用。
