Learning-dependent 4 Hz synchronization in the posterior striatum, lateral geniculate nucleus, and visual cortex.

The posterior striatum (pStr) is thought to play a crucial role in perceptual learning by maintaining stable sensory representations based on past experience and associating them with appropriate motor responses. However, how the pStr neuronal activity acquires these representations, in particular the functional significance of the interactions between the pStr and its sensory input regions, remains largely unexplored. Here, we conducted simultaneous and chronic electrophysiological recordings from the pStr, dorsolateral geniculate nucleus, and visual cortex in rats performing a visual discrimination task. We found that learning enhanced 4 Hz synchronization between the pStr and visual areas, especially during decision-making periods. Moreover, following learning, regular-spiking neurons in the pStr exhibited increased firing rates and stronger phase-locking to these oscillations. These results highlight the involvement of the pStr in visual perceptual learning and indicate the role of 4 Hz oscillations within sensory-striatal circuits in facilitating sensorimotor integration required for efficient task performance.