The distribution of 5-HT₃ recognition sites in the marmoset brain

The distribution of the binding of [³H]GR65630 (0.2 nM) to putative 5-HT₃ recognition sites in the brain of the common marmoset was assessed using autoradiography. Specific binding was heterogenously distributed with the highest densities found in discrete nuclei of the lower medulla (nucleus tractus solitarii, dorsal motor nucleus of the vagus nerve, nucleus of spinal trigeminal nerve tract and the area postrema). In forebrain areas, relatively high binding densities were located in the medial habenula nucleus and the hippocampus (CA3, CA4 and fascia dentata). Low levels of specific binding in the rest of the forebrain hindered quantification.