The Journal of Neurophysiology Vol. 85 No. 6 June 2001, pp. 2590-2601
Copyright ©2001 by the American Physiological Society
Primate Rhinal Cortex Participates in Both Visual Recognition and
Working Memory Tasks: Functional Mapping With 2-DG
Lila
Davachi and
Patricia S.
Goldman-Rakic
Section of Neurobiology, Yale University School of Medicine, New
Haven, Connecticut 06511
Davachi, Lila and
Patricia S. Goldman-Rakic.
Primate Rhinal Cortex Participates in Both Visual Recognition and
Working Memory Tasks: Functional Mapping With 2-DG. J. Neurophysiol. 85: 2590-2601, 2001. The rhinal
cortex in the medial temporal lobe has been implicated in object
recognition memory tasks and indeed is considered to be the critical
node in a visual memory network. Previous studies using the
2-deoxyglucose method have shown that thalamic and hippocampal structures thought to be involved in visual recognition memory are also
engaged by spatial and object working memory tasks in the nonhuman
primate. Networks engaged in memory processing can be recognized by
analysis of patterns of activation accompanying performance of
specifically designed tasks. In the present study, we compared
metabolic activation of the entorhinal and perirhinal cortex during the
performance of three working memory tasks [delayed response (DR),
delayed alternation (DA), and delayed object alternation (DOA)] to
that induced by a standard recognition memory task [delayed match-to-sample (DMS)] and a sensorimotor control task in rhesus monkeys. A region-of-interest analysis revealed elevated local cerebral
glucose utilization in the perirhinal cortex in animals performing the
DA, DOA, and DMS tasks, and animals performing the DMS task were
distinct in showing a strong focus of activation in the lateral
perirhinal cortex. No significant differences were evident between
groups performing memory and control tasks in the entorhinal cortex.
These findings suggest that the perirhinal cortex may play a much
broader role in memory processing than has been previously thought,
encompassing explicit working memory as well as recognition memory.
