DISTRIBUTION OF GABA-LIKE IMMUNOREACTIVITY IN THE OCTOPUS BRAIN

This paper presents the first evidence that some neurons in the octopu s CNS contain delta-amino butyric acid (GABA). Using conventional immu nohistochemical methods with appropriate controls, we obtained positiv e staining with an antibody to GABA in fibres in the neuropil of many lobes of the brain of the northern octopus Eledone cirrhosa. In severa l lobes cell bodies were also stained. Staining was not uniformly dist ributed in the brain nor within a particular lobe: some regions staine d strongly, others not at all. These findings suggest that GABA should be added to the already long fist of putative neurotransmitters in th e cephalopod CNS.