Evaluation of sink and source patterns in the prefrontal cortex of a monkey

Advances in microfabrication technology have enabled the development of multi-contact electrodes with precise inter-contact spacing from tens to hundreds of micrometers. Using this technology, we can record multiple neural activities in the brain simultaneously. Based on the local field potentials (LFPs) recorded from each contact, it is possible to estimate the current source density (CSD), which is considered to reflect synaptic input. Analysis of both spike activities, reflecting the output of neurons, and CSD is a promising approach to examining the functional properties of the neuronal circuits underlying animals’ behavior. However, the standard CSD method does not always reconstruct the actual CSD. A few methods have been proposed to overcome this problem, but these have not been tested using the LFPs of behaving animals. We present the preliminary results of a comparison between standard and new CSD approaches to the LFPs recorded from the prefrontal cortex of a behaving monkey.