Oscillation in the monkey cortex

Abstract

Each neuron must know that they are processing the same information. Synchronously oscillating activity found in the primary visual cortex of cats can contribute to these processes. Similar oscillatory activities have also been reported in the sensory or motor cortices of monkeys. However, it is not clear if the synchronous oscillation is a common feature across the cortex of monkeys. Thus, we searched for the oscillatory activities in the frontal cortex of the behaving monkeys. We found a type of bursting cells that often showed rhythmic burst related to the task events. Based on the findings of intracellular recordings in the slice or anesthetized preparations, we classified these neurons as the fast rhythmic bursting (FRB) cells. FRB cells showed relatively short and stable interspike intervals (<5 ms) and small number of spikes within a burst (2–5 spikes). FRB cells often showed repetitive or a rhythmic burst at 25–80 Hz. The firing pattern of the FRB cells had a resemblance to that of the chattering cell reported in the cat's visual cortex and, could contribute to the synchronous activation of cortical neurons during the control of behavior.