Regeneration of the forebrain of the Japanese carp, Cyprinus carpio: a Golgi analysis.

The regeneration of the forebrain of the Japanese carp, Cyprinus carpio was examined with the rapid Golgi method. Characteristic of both 40 and 70 day regenerated forebrains was a proliferation of the spine processes of ependymal cells. Concomitant with this spinous augmentation was the appearance of swellings in many of the processes. Adjacent to the ependyma were cells that appeared to bud-off the ependyma and become migrating neuroblasts. The examination of the neurons in both normal and regenerated forebrains revealed no obvious and consistent differences between the configurations in both cases. In contrast to this finding, examination of the incoming axons showed numerous swellings and enlargements which were presumed to be immature synapses. The signifiance of these findings to the regeneration of the forebrain is discussed.