The commissural interconnections of the inferior colliculus in the albino mouse.

In the inferior colliculus of the mouse, 4 cell types project across the collicular commissure: small to medium sized spiny cells, small to medium sized spineless cells, medium sized sparsely spinous neurons and large cells. The axons of large cells give rise to a great number of ipsi- and contralateral collaterals terminating in nests of fine varicose fibers. The anterograde transport of HRP revealed that following injections into the central nucleus, the axonal terminals are arranged in a fixed, ipsi- and contralateral banding pattern across the central, pericentral and external nucleus irrespective of the location of the injection. On the contrary, the position of projecting cells varies with the location of the injection, though the area emitting commissural fibers is not completely homotopic to the injection site but subordinated to the axonal banding pattern.