My research aims to understand how synaptic level changes in basal ganglia and hippocampal circuits underlie memory encoding and behavioral learning, and how these processes break down in neurodegenerative and neurological diseases. This talk will highlight findings from in vivo electrophysiology studies that demonstrate the coordinated activation of sensorimotor and associative striatal circuits as well as hippocampus as rats learn and perform a T-maze task. Taking a closer look at the synaptic mechanisms that operate in just one of these systems during learning, I will also present recent work that examines specific actions of acetylcholine in modulating hippocampal synapses.