In vivo voltammetric measurement of extracellular 5-hydroxyindoleacetic acid in the denervated striatum after transplantation of mesencephalic raphe neurons.

In vivo differential pulse voltammetry with carbon fiber electrodes was used to monitor extracellular 5-hydroxyindoleacetic acid (5-HIAA) levels in a serotonergic denervated target area, the striatum, before and after transplantation of mesencephalic raphé nuclei into the lateral ventricle in the rat. The amplitude of the electrochemical signal recorded in the striatum on the transplanted side was found to be comparable to that measured in control striatum whereas the signal measured from the contralateral nontransplanted striatum was negligible. These findings suggest that mesencephalic raphé nuclei transplants establish connections with the host tissue.