FITC-LABELED ALPHA-BUNGAROTOXIN VISUALIZA TION OF NEURONS IN THE CENTRAL-NERVOUS-SYSTEM OF PTEROPODIAL MOLLUSK CLIONE-LIMACINA

FITC-labelled alpha-bungarotoxin (alpha BT[FITC]) was used to identify acetylcholine (ACh)-sensitive neurons in the central nervous system o f pteropodial mollusc Clione limacina. Two small symmetrical neurons w ere stained with alpha BT[FITC] on the dorsal surface of the cerebral ganglia. The staining was highly specific as it was completely blocked by preincubation in alpha-bungarotoxin [alpha BT] at very low concent ration (10(-9) M). Nicotinic agonists and antagonists efficiently prev ented alpha BT[FITC] staining while muscarinic agonists and antagonist s had no effect. These findings confirm the suggestion that alpha BT[F ITC] binds to nicotinic ACh receptors. The possible role is discussed of alpha BT[FITC]-stained cells in the complex of hunting behavior of Clione.