Layer 3 patchy recurrent excitatory connections may determine the spatial organization of sustained activity in the primate prefrontal cortex

Anatomical studies of primate prefrontal cortex show strong and spatially modulated lateral excitatory connections among pyramidal neurons in the supra-granular layers. We study the role of patchy lateral excitatory connections in generating spatially localized pulses of sustained activity. When the patchy connections drive the "ring no spatially localized sustained activity is possible. When the local connectivity is strong enough to produce sustained activity, a localized standing pulses are possible. Additional punctate stimuli boost, or extinguish the standing pulse-system depending on their spacing. When the patchy lateral connections form distinct sub-systems, spatially restricted systems of multiple pulses of sustained activity are observed over a wide range of connection strength parameters. ( 2000 Published by Elsevier Science B.V. All rights reserved.