PUTATIVE NEUROTRANSMITTERS IN THE CEREBRAL GANGLIA OF THE TUNICATE CIONA-INTESTINALIS

1. A number of sensitive procedures were used to analyse the dopamine, noradrenaline, octopamine, 5-hydroxytryptamine and putative amino acid distribution in the cerebral ganglia of the tunicate Ciona intestinalis. 2. The following putative transmitter substances exist in the nervous tissue: dopamine, noradrenaline, GABA, taurine, glutamate, glycine and aspartate. No trace of either 5-hydroxytryptamine or octopamine was found. 3. An amine-sensitive adenylate cyclase is also present in Ciona nervous tissue. Dopamine, noradrenaline, 5-hydroxytryptamine and octopamine at 100 μM concentrations all stimulated adenylate cyclase activity to the same extent. All the amino acids tested had no effect on the adenylate cyclase. 4. The significance of these findings is discussed. © 1979.