| Abstract: | The relationship between the primary auditory cortex and the claustrum has been re-examined in the cat with axoplasmic flow and axonal degeneration methods. Labelled cells are found in a restricted part of the claustrum after injections of HRP or HRP-WGA in the primary auditory cortex, but they are relatively few in number and are palely stained. The number of labelled cells and their depth of staining are greatest at 72 h (the longest survival time used here), and this survival period an occasional labelled cell is also present in the claustrum of the contralateral hemisphere. No labelled cells are seen after 24 h. After small lesions in the primary auditory cortex, fibre and terminal degeneration are present in the part of the claustrum where labelled cells are seen with axoplasmic flow techniques. It is concluded that there are reciprocal connections between the primary auditory cortex and the claustrum, but the rate of axoplasmic flow is unusually slow. |
