3D SPATIAL RELATIONSHIPS OF HISTOCHEMICAL ACTIVITY IN THE RAT SUPERIOR COLLICULUS

Recent evidence points to the existence of lattices of acetylcholinest erase (AChE) and cytochrome oxidase (CYO) in deep layers of the superi or colliculus. We sought to further describe their localization within the rat superior colliculus using new three dimensional (3D) digital imaging techniques. Texture maps of AChE staining within the stratum g riseum intermediale (SGI) suggest a sheet of high enzyme activity punc tuated by areas of pallor. This lattice of dense staining covered the caudal end of the colliculus and extended rostrally along the medial b ank. Discrete regions of low staining were most apparent within the IV c subdivision of SGI. A similar examination of CYO activity failed to reveal any compartmentalization.