Abstract
To investigate the involvements of the rat hippocampus (Hip) and prefrontal cortex (PFC) in inhibitory control of behavior, we recorded local field potentials (LFPs) from the Hip and PFC during an operant discrimination task and analyzed the LFPs during stimulus presentation for no-reward (S-). Rats received the discrimination training using light and sound as the discrimination stimuli (one for S+, and the other for S-) until a stable discriminative performance was achieved. After that, recording electrodes were implanted into Hip and PFC, and we recorded the LFPs during the discrimination task. Obtained data were filtered with band-pass filters of 8-16, 16-32, 32-64 and 64-128Hz, and those activities were analyzed with time resolution of 1 ms. The Hip 8-16Hz LFP activities increased gradually across time during S- presentation, and the activities of 64-128Hz LFPs increased during S- presentation in both Hip and PFC. These results suggest that Hip and PFC higher gamma-band activities relate to inhibitory control of behavior. Given the involvement of PFC in inhibitory control of behavior, PFC higher gamma-band activities may reflect some inhibitory function and may cause the increase of Hip higher gamma-band activities. [J Physiol Sci. 2007;57 Suppl:S167]
