Projection of morphologically identified superior colliculus neurons to the lateral posterior nucleus in the cat.

Using the intracellular recording and staining techniques we studied types of superior colliculus cells which project to the ipsilateral nucleus lateralis posterior (LP) and the nature of retinal afferent inputs to them. Five morphologically identified colliculus cells were antidromically driven by stimulation of the tectorecipient zone of the LP. The nature of retinal afferent inputs to these cells was determined by measuring conduction velocity between the optic chiasm and the optic tract. Four of the five, innervated by W-retinal ganglion cells, were narrow-field vertical and wide-field vertical cells, located in the upper and lower parts of the superficial gray layer. The remaining one, innervated by Y-fibers, was a large narrow-field vertical cell, located in the lower part of the same layer.