Localization of N-acetylserotonin (NAS) in the rat hindbrain by immunohistology

1.1. A specific anti-NAS antibody and fluorescein-labelled second antibody were employed to investigate the topographic distribution of immunoreactive NAS (INAS) in the hindbrain of the rat.2.2. Positive identification of INAS was confirmed in the granular layer of the cerebellum, the spinal tract of the fifth cranial nerve and the pontine reticular formation.3.3. INAS was also identified in neuronal cell bodies and processes of Purkinje cells, all cerebellar nuclei, the locus coeruleus and other brain stem regions.4.4. The pattern of INAS distribution was found to be different from that of serotonin and melatonin.5.5. Overlap of INAS- and NE- containing structures was identified in areas such as cerebellum and locus coeruleus, suggesting the possibility of a functional connection between these substances in some regions.