AbstractInhibitory interneurons are believed to realize critical gating functions in cortical circuits, but it has been difficult to ascertain the content of gated information for well characterized interneurons in primate cortex. Here, we address this question by characterizing putative interneurons in primate prefrontal and anterior cingulate cortex while monkeys engaged in attention demanding reversal learning. We find a subclass of narrow spiking neurons with relative suppressive effects on the local circuit indicating they are inhibitory interneurons. The activity of one subclass of these interneurons prominently indexed area-specific information in their firing rates and in event-triggered (35-45 Hz) gamma band synchronization. Firing rates and gamma synchrony of this interneuron subclass indexed in prefrontal cortex the uncertainty of attention cues, and in anterior cingulate cortex the unexpectedness of outcomes during learning. Computational analysis suggest that these interneuron-specific activity dynamics reflect in prefrontal cortex the gating of expected stimulus values into choice probabilities, and in anterior cingulate cortex the gating of chosen stimulus values and the received rewards into reward prediction errors. These findings elucidate an electrophysiologically characterized interneuron subclass in the primate, that forms gamma synchronous networks in two different areas while realizing an area-specific computation during adaptive goal-directed behavior.
Differential alterations of kainate receptor subunits in inhibitory interneurons in the anterior cingulate cortex in schizophrenia and bipolar disorder