Top-Down Regulation of Laminar Circuit via Inter-Area Signal for Successful Object Memory Recall in Monkey Temporal Cortex.

Memory retrieval in primates is orchestrated by a brain-wide neuronal circuit. To elucidate the operation of this circuit, it is imperative to comprehend neuronal mechanisms of coordination between area-to-area interaction and information processing within individual areas. By simultaneous recording from area 36 (A36) and area TE (TE) of the temporal cortex while monkeys performed a pair-association memory task, we found two distinct inter-area signal flows during memory retrieval: A36 spiking activity exhibited coherence with low-frequency field activity in either the supragranular or infragranular layer of TE. Of these two flows, only signal flow targeting the infragranular layer of TE was further translaminarly coupled with gamma activity in the supragranular layer of TE. Moreover, this coupling was observed when monkeys succeeded in the retrieval of the sought object but not when they failed. The results suggest that local translaminar processing can be recruited via a layer-specific inter-area network for memory retrieval.