Neuronal activity driven by the VTA modulates information coding capacity in the prefrontal cortex

C. J. MININN; CAIAFA, C; B SILVANO ZANUTTO; S. LEW

Chicago

Congreso; Neuroscience 2015; 2015

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Topic:++F.02.f. Executive function: Decision makingAuthors:C. MININNI1, C. CAIAFA2, S. ZANUTTO3, *S. E. LEW4; 1Inst. de Medicina y Biología Exptl. - CONICET, Buenos Aires, Argentina; 2CONICET, Buenos Aires, Argentina; 3Inst. de Medicina y Biología Exptl. - CONICET, Inst. de Ingeniería Biomédica, UBA, Buenos Aires, Argentina; 4Univ. de Buenos Aires, Capital Federal, ArgentinaAbstract:Processing information in a neural population needs from mechanisms that assure rapid encoding and enough information capacity, while protecting the code from distractors. Constrained to the high metabolic cost of spike emission, strategies based on firing rate coding face unavoidable problems to fulfil those requirements at the time they appear to be inefficient. However, it is well known that, in the prefrontal cortex (PFC), information is maintained by means of sustained spiking activity, during and after stimulus presentation and, in normal conditions, this activity is resistant to distractors. It is also known that dopamine released from the ventral tegmental area (VTA) is a critical component needed to achieve stimulus selectivity and distractor rejection in the PFC. To understand VTA-modulated statistical properties of information processing at the PFC, we made simultaneous multielectrode recordings in the PFC and the VTA of rats performing a GO/NO-GO task (N=4). We also made similar recordings in urethane anaesthetised animals (N=8), so as to know whether our findings in awake animals belong to structural or functional properties of the VTA-PFC system. We found an enhancement of information capacity in the PFC, which is correlated with the average activity of VTA neurons in both, anaesthetised and behaving animals. However, when we compute how efficient the population of PFC neurons is, we found that information capacity increases in a cost-efficient way only in awake animals and during stimuli presentation. Moreover, efficiency in the PFC was proportional to the average activity of VTA neurons.