FUNCTIONAL ARCHITECTURE OF MONKEY PREFRONTAL CORTEX

前额皮质（PFC）区域明显扩大

The prefrontal cortical (PFC) regions are markedly expanded and differentiated in the primate brain, and appear to be specialized for the mediation of certain complex cognitive functions. In addition, multiple lines of evidence suggest that the PFC may be a site of dysfunction or structural pathology in human neuropsychiatric disorders, such as schizophrenia, that disrupt higher cognitive functions. Understanding the possible role of PFC dysfunction in the pathophysiology of schizophrenia requires knowledge, in the normal state, of the neural elements present in PFC, their distinguishing features and roles in the intrinsic organization of PFC, and of the manner in which the resultant functional architecture influences, and is influenced by, the activity of other brain regions. In order to address these issues, we plan to characterize the intrinsic excitatory connections of the primate PFC, using the macaque monkey as a model of the human. Pyramidal neurons, the major class of cortical efferent neurons, also give rise to local axon collaterals which are major contributors to the propagation of intracortical excitatory activity. These collaterals extend for a considerable distance horizontally, and furnish regularly distributed clusters of terminal fields, which in monkey PFC, appear to be arrayed in a lattice structure with a unique stripe-like appearance. In the proposed studies, we wish to define the exact 3-dimensional geometry of this lattice structure, and its relation to other patterns of excitatory and inhibitory circuitry. However, understanding the functional characteristics of this intracortical circuitry depends, at present, upon extrapolations from electrophysiological studies conducted in other cortical regions or species, whose functional architecture is likely to be substantially different from that of primate PPC. Consequently, we have developed an in vitro slice preparation of monkey PFC in order to provide detailed information on the biophysics and synaptic microphysiology of the intrinsic connectivity of monkey PFC. The power of the proposed experimental strategy results from the integration of structural and electrophysiological approaches which permit the testing of specific hypotheses about the functional circuitry of primate PFC.