Appearance of calretinin-immunoreactive neurons in the upper layers of the rat superior colliculus after eye enucleation

The effects of retinal deafferentation on a calcium-binding protein, calretinin, in the upper layers (superficial gray layer and optic nerve layer) of the rat superior colliculus were examined. In intact rats and on the ipsilateral side of unilaterally eye-enucleated rats, the superficial gray layer and optic nerve layer contained a few dispersed calretinin-immunoreactive cells. On the contralateral side to the enucleation, the number of immunostained cells in the superficial gray layer and optic nerve layer was increased. These findings suggest that retinal deafferentation results in an increase in contents of calretinin in some cell bodies within the upper layers of the superior colliculus.