4.5. Collection of Brain Tissue

After the behavioral experiments, seven mice in each group were anesthetized with 10% v/v chloral hydrate, followed by dissection on ice to collect the striatum. The remaining mice were perfused intracardially with phosphate buffer solution (PBS), followed by 4% v/v paraformaldehyde (PFA). Brains were dissected and fixed in 4% v/v PFA at 4 °C overnight and were then dehydrated successively with 20% and 30% sucrose solution (w/v) prepared in PBS, embedded in optimum cutting temperature (O.C.T., Sakura Finetek, USA, Inc., Torrance, CA, USA) compound, and cut into 20 μm-thick sections on a Leica microtome (Leica Biosystems Nussloch GmbH, Heidelberger, Germany).