Showing papers by "Pavel M. Balaban published in 1980"

Effect of gamma aminobutyric acid on command neurons of Helix lucorum snail neurons

Abstract: Studies have been made of the effect of GABA on the activity of identified neurones of the central nervous system of the snail Helix lucorum. GABA perfusion within first 10 min resulted in the increase of reactions to intracellular and transsynaptic stimulation of the neurones studied, depolarization by 3-4 mV being also observed. After this period, further perfusion decreased the spontaneous activity and neuronal reaction, this effect being accompanied by the decrease in membrane resistance. Synaptic and axonal conduction remained unaffected, although cells responded by the action potentials only to strong stimulation. After 30 min of GABA perfusion, tactile stimulation, which in the intact animals induces the avoidance reaction led to opening of the respiratory orifice, i.e. a component of the respiratory cycle.

Sensitization and habituation in command neurons of the defensive reflex in Helix lucorum.

Abstract: 1. Regular tactile stimulation of the snail's foot causes a temporary increase (to the second stimulus), followed by a decrease in amplitude of the unconditioned reflex of pneumostome closure. 2. Of all identified neurons studied, only the responses of the command neurons of the defensive reflex of pneumostome closure were increased to the second stimulus in the series, whereas responses of nerve cells participating in the processing of sensory information decreased steadily. Sensitization of responses of the command neurons is evidently a mechanism of behavioral sensitization. 3. The cause of sensitization of the command neurons is long-lasting depolarization in response to tactile stimulation, arising after the spike discharge of the cell and facilitating responses to subsequent stimulation.