A project to study how reward and punishment modulate visually evoked responses in the primary visual cortex

CAMILA L. ZOLD; MARIA FLORENCIA SANTOS

Congreso; XXXV Congreso Anual de la Sociedad Argentina de Neurociencia; 2020

The primary visual cortex (V1) neuronal activity encodes basic properties of visual stimuli. Experience dependent plasticity has been observed in V1 as a way to improve visual perception. However, recent studies show that V1 neural plasticity is also related to reinforcement learning. When rodents experience an association between a visual stimulus and a contingent future reward, a proportion of V1 neurons develop reward timing activity. Cholinergic projections from the basal forebrain (BF) have been shown to be necessary and sufficient to induce the reward timing activity in V1. However, little is known about whether this activity evolves simultaneously in the BF and V1 during learning. On the other hand, if V1 encodes the behavioral significance of visual stimuli in a general way, we hope that it may also encode the time interval between visual stimuli and contingent punishments. To unveil this, we implanted C57BL/6 adult male mice with a microelectrode array in V1 and performed electrophysiological recordings in head-fixed mice learning a visually cued rewarded task. Mice were trained to perform a lick sequence in order to receive a water reward in 70% of cases. We trained 4 mice that successfully learned the task and we identified neurons responding to visual stimulus. To continue with the project, we plan to carry out simultaneous recordings on V1 and BF and also analyze V1 activity in animals exposed to Pavlovian stimulus-reward and stimulus-punishment associations.