Deflection of selected optic fibers into a denervated tectum in goldfish

Abstract

In goldfish, one eye was enucleated, and after two or more weeks a select fraction of optic fibers from the remaining eye was deflected into the ipsilateral optic tectum. At varying intervals, the optic reinnervation of the ipsilateral tectum was measured by autoradiography and electrophysiologic mapping. Both methods indicated the deflected optic fibers not only innervated the appropriate region of tectum but also spread beyond this, occupying a total area that was several times greater than normal. Correlated with this spreading were low grain density in the autoradiograms and reduction in the number of amplitudes of units recorded electrophysiologically. The electrophysiology also revealed this projection to be almost devoid of topographic organization, showing only a crude but appropriate polarity.