Non-stationarities in the prefrontal cortex - ventral tegmental area interaction

C. J. MININNI, S. ZANUTTO

Washington DC

Congreso; Annual Meeting of the Society for Neuroscience; 2011

Society for Neuroscience

Prefrontal Cortex (PFC) and Ventral Tegmental Area (VTA) are key brain regions in the reward neural circuit, performing essential tasks in behavioral flexibility, working memory, decision-making processes and planning, among others. Both areas are mutually connected: the PFC sends glutamatergic projections to the VTA, while dopaminergic neurons in the VTA project back to the PFC, modulating synaptic plasticity phenomena. Besides, electrophysiological evidence for synchronic activity between both areas has been provided. Nonetheless, functional connectivity is usually assessed by taking electrophysiological recordings as a whole. In order to find non-stationarities in the degree of correlation among neurons activity, a novel searching algorithm was used, based on fragmenting the recording in segments of varying lengths and frames. Simultaneous electrophysiological activity of PFC and VTA neurons was obtain in anesthetized rats using tetrodes in each area, and segmented correlations were done for all possible pairs in each simultaneous PFC-VTA recording. The analysis proved that two given neurons may exhibit correlated or uncorrelated activity depending on the segment of the recording which is considered. Interestingly, many pairs that didn’t show significant interactions when analyzing the whole recording proved to be functionally connected when the appropriate window size and frame was used. Thus, recordings that are not significantly correlated as a whole may contain correlated segments confounded with “noisy” activity. Conversely, recordings that are correlated as a whole may not be homogenously correlated. The study of the neuronal activity as a non-stationary process may give valuable information about the functioning of the neuronal circuits, by analyzing the patterns of synchronization and desynchronization in a population of neurons.