Cj. Shi et Md. Cassell, Perirhinal cortex projections to the amygdaloid complex and hippocampal formation in the rat, J COMP NEUR, 406(3), 1999, pp. 299-328
The differential efferent projections of the perirhinal cortex were traced
by using anterograde and retrograde tracing techniques. The dorsal bank cor
tex (area 36) projected lightly to the lateral entorhinal cortex and more s
trongly to the lateral, posterolateral cortical, and posterior basomedial a
mygdaloid nuclei and amygdalostriatal transition zone. The ventral bank (do
rsolateral entorhinal cortex) projected to the lateral entorhinal cortex, d
orsal subiculum, and subfield CA1 and mainly targeted the basolateral amygd
aloid nucleus. Corticocortical projections from the dorsal and ventral bank
s targeted different cortical areas. The fundus of the rhinal sulcus (area
35) projected to both lateral and medial entorhinal cortices, ventral subic
ulum, lateral and basolateral nuclei, and amygdalostriatal transition zone.
Corticocortical projections targeted areas projected to by both dorsal and
ventral banks and also by second somatosensory area, first temporal cortic
al area, and striate cortex. Neurons projecting to the lateral nucleus were
distributed in all layers of the dorsal bank, wheras those projecting to C
A1 and subiculum were found in superfical layers (mostly layer III) of the
ventral bank. Projections to the basolateral nucleus arose from superfical
layers (mostly layer II) of the fundus and deep layers of the ventral bank.
Furthermore, projections to the amygdala mostly arose from rostral levels,
whereas hippocampal projections primarily originated caudally. The rat per
irhinal cortex is heterogeneous in its efferent connectivity, and distinct
projections arise from the dorsal and ventral banks and fundus of the rhina
l sulcus. The widespread cortical connectivity of the fundus suggests that
only this part of the perirhinal cortex is similar to area 35 of the primat
e brain. (C) 1999 Wiley-Liss, Inc.