Interaction at multiple temporal scales in the prefrontal cortex-ventral tegmental area circuit

C. J. MININNI, B. S. ZANUTTO

San Diego

Congreso; Neuroscience Meeting Planner.; 2010

Society for Neuroscience

Authors: C. J. MININNI1, *B. S. ZANUTTO2; 1IByME-CONICET, Buenos Aires, Argentina; 2Univ. Buenos Aires-CONICET, Buenos Aires, Argentina     Abstract: Prefrontal Cortex (PFC) and Ventral Tegmental Area (VTA) are key brain regions in the reward neural circuit performing essential tasks in behavioural 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 projects back to the PFC, modulating synaptic plasticity phenomena. Although several works have been made describing the effects the VTA has on the PFC, the dynamic of the interaction from a circuital perspective has been poorly studied.In this work we performed simultaneous extracellular electrophysiological recordings of neuronal populations with tetrodes in the PFC and the VTA in anesthetized rats, to characterize the dynamics of these areas and their interaction. Pairwise correlations between PFC and ATV neuronal populations were performed. We found significant correlations in a short (1 msec) and in a long (3000 msec) time scale. Most remarkably, interactions in both scales may coexist in the same circuit. In this case, the sign of the interaction could be positive in the short scale and negative in the long scale, or vise versa.The cross-correlogram analysis showed that a subset of the interactions occurred in an oscillatory fashion. In particular, VTA neurons separated by hundreds of microns may oscillate in synchrony with the same PFC neurons, and each PFC-ATV neuron pair shows shifts of different magnitude. The set of all the oscillations showed phase shifts ranging from 3% to 50% of the oscillation period, and in most cases VTA activity peak preceded the CPF peak. This directionality in the interaction was confirmed by Granger Causality calculus: In 20% of the neuron pairs studied, the causality was significant in only one direction, the VTA activity causing the CPF activity in most of the cases.Our results describe the interaction profile between the CPF and the ATV, allowing a better understanding of the role that this circuit plays in the neural circuit of lerning.     Disclosures:  C.J. Mininni, None; B.S. Zanutto, None.     Keyword(s): reward circuit       Prefrontal Cortex       Ventral Tegmental Area       [Authors]. [Abstract Title]. Program No. XXX.XX. 2010 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2010. Online. 2010 Copyright by the Society for Neuroscience all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.