[Functional activity of ganglion neurons from the pond snail upon temperature variations]

Changes in the functional state of the synthetic apparatus of neurons of the peripharyngeal ring of the mollusk Lymnaea stagnalis upon elevating the temperature of the habitat from 4 to 18-22 degrees C were studied. In the first series of experiments, it was found that the synthetic activity of neurons of the great and small parietal, visceral, and pleural ganglia increases on the average by 70%. In the second series of experiments, changes in the average synthetic activity for all ganglia at 4.0, 6.5, 13.0, 16.8, 20.5, 21.5, 21.9, and 22.0 degrees C were studied. The increase in the synthetic activity of neuron cytoplasm (35% higher than the control values at 4.0 degrees C) was maximal at 13.0 degrees C; then the synthetic activity decreased to reach the level 20% higher than the control. The physiological range of temperature-dependent changes in the functional state of neurons was determined.