Coexistence of galanin-like immunoreactivity with classical transmitters and other neuropeptides in the CNS

Immunohistochemical studies on the localization of the peptide galanin (GAL) (Tatemoto et al., 1983) in the central nervous system of several species including man have been presented (Rokaeus et al., 1984; Ch’ng et al., 1985; Skofitsch and Jacobowitz, 1985b; Melander et al., 1986; Gentleman et al., 1989). The distribution patterns observed often corresponded to areas known to contain “‘classical transmitters” such as adrenaline, noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT), acetylcholine (ACh) and gamma-aminobutyric acid (GABA). It has previously been found that many other peptides often occur in the same neurons as these “classical transmitters” and may modulate the response to these messengers and/or participate in neuronal signalling in other ways (see e.g Hokfelt et al., 1980, 1986; Cuello, 1982; Chan-Palay and Palay, 1983).