Authors:Magda Alania, Varya Dyakonova, and D. A. Sakharov
In the pond snail Lymnaea stagnalis, D-glucose action was investigated on electrical activity of identified central neurons. In the CNS preparations isolated from specimens that starved for 24-96 h, D-glucose added to a standard or HiDi saline at 500-700 mg/ml effectively hyperpolarized ca. 90% of feeding related neurons B1, SO and CGC. However, not all feeding-related neurons examined were responsive to glucose. Experiments on cells of the serotonergic Pedal A cluster have shown that hyperpolarizing action of D-glucose is retained following complete isolation of «hunger» neurons. Threshold concentration producing 1-3 mV hyperpolarization was ca. 50 mg/ml. The results suggest a direct glucose involvement in the mechanisms that control feeding behavior in Lymnaea.