Inhibitory control by an integral feedback signal in prefrontal cortex: a model of discrimination between sequential stimuli.

摘要: The prefrontal cortex (PFC) is known to be critical for inhibitory control of behavior, but the underlying mechanisms are unclear. Here, we propose that can instantiated by an integral signal derived from working memory, another key function PFC. Specifically, assume integrator converts excitatory input into a graded mnemonic activity provides (integral feedback control) upstream afferent neurons. We demonstrate this scenario in neuronal-network model temporal discrimination task. task requires memory vibrational frequency (f1) initial stimulus (stimulus 1), followed comparison (f2) second 2) with stored f1 and binary decision (f2 > or f2 < f1). generated 1 gates later inputs based on amplitude difference – enables subset neurons reverse their tuning between 2, when they become tuned difference, f1. These maintain lower firing rate during delay compared peak 1. A neurons, delay, reaches 2 depends maximum f2. Our work suggests circuit mechanism across time predicts neuronal behavior tested experimentally.