VTA-dependent regulation of neuronal synchrony and entropy in the PFC emerges along trajectories of balanced excitation-inhibition

C. J. MININNI; B. S. ZANUTTO; S. E. LEW & B. S. ZANUTTO

Washington

Congreso; Neuroscience 2014; 2014

Society for Neuroscience

VTA-dependent regulation of neuronal synchrony and entropy in the PFC emerges along trajectories of balanced excitation-inhibition Location: WCC Hall A-C Presentation time: Wednesday, Nov 19, 2014, 8:00 AM -12:00 PM Presenter at Poster: Wed, Nov. 19, 2014, 8:00 AM - 9:00 AM Topic: ++F.02.u. Prefrontal/striatal systems Authors: C. J. MININNI1, *B. S. ZANUTTO2, S. E. LEW3;  1IByME - CONICET, Buenos Aires, Argentina; 2Univ. Buenos Aires-CONICET, Buenos Aires, Argentina; 3Inst. de Ingeniería Biomédica - UBA, Buenos Aires, Argentina Abstract: The Prefrontal Cortex (PFC) and Ventral Tegmental Area (VTA) are key brain regions for understanding goal directed behavior. The PFC is proposed to be a decision making structure, integrating sensory information and initiating behavioral responses, while the VTA is known to modulate changes in synaptic efficacy and neural population dynamics in the PFC, through its direct VTA-PFC projections, both dopaminergic and GABAergic In the present work, 4 Long Evans rats were trained in a GO/NOGO sound discrimination task under a head-restrained paradigm. We recorded neural activity in the PFC and the VTA simultaneously during the discrimination task. A pool of 248 single cells (95 from PFC and 153 from VTA) were selected for analysis. While in GO trials, neurons from PFC and VTA steadily increased their firing rate during tone presentation, in the NOGO trials a transient increase was observed, followed by a return to baseline levels. On the other hand, pairwise correlations between PFC neurons changed during the decision period. During GO trials correlations increased significantly, whereas in NOGO trials correlations decreased. Surprisingly, along with the increase in correlation values, pairwise entropy also increased. We show that this singular relationship between correlation and entropy can be explained with a balanced excitation-inhibition model of PFC, in which signal and noise correlation are parameterized. Increasing values of both correlation and entropy could be achieved by reducing signal correlation and rising noise correlation proportionally. The simultaneously recorded VTA activity suggests that the VTA firing could modulate the synaptic conductances among the PFC neurons, thus changing the balance between signal and noise correlation and driving the observed correlation/entropy profile. Taken together, our results suggest that VTA activity drives prefrontal correlations and entropy along trajectories constrained to the balanced excitation-inhibition regime. Disclosures:  C.J. Mininni: None. B.S. Zanutto: None. S.E. Lew: None. Keyword (s): PREFRONTAL CORTEX VENTRAL TEGMENTAL AREA NEURAL CODING Support: UBACyT 200 20 100 100 902 PICT 2012-1519 PIP 112 201101 01054 UBACYT 200 20 100 100 978.