Parvalbumin in rat superior colliculus.

Parvalbumin-like immunoreactivity (PA-LI) has been studied in sections of the superior colliculus (SC) of the rat and its distribution compared to the patterns of acetylcholinesterase (AChE) and cytochrome oxidase (CO) staining. In the intermediate layers it was found that PA-LI is spatially associated with AChE only in the medial part of the SC, but assumes a complementary distribution further laterally. There was a positive correlation between PA-LI and CO. We conclude that the patterns of PA-LI and CO are not systematically related to collicular input known to be associated with the AChE-rich zones, but may reflect adherence to channel separation beyond the terminal fields of clustered afferents.