Showing papers by "Pavel M. Balaban published in 1987"
TL;DR: In 5,7-DHT-treated animals some components of the feeding behavior and withdrawal reaction changed as well, moreover the sensitization of the withdrawal reaction evoked by rhythmic tactile stimulation disappeared in preparations made from drug-treated snails.
73 citations
TL;DR: The result suggests that the absence of sensitization, as well as inability to be aversively conditioned is related to 5-hydroxytryptamine level, which changes during postnatal development in the snail.
37 citations
TL;DR: It is shown that the same neurone can generate spikes in response to opposite directions of polarizing currents, and thresholds of spontaneously active neurones to extracellular currents were significantly lower than thresholds of silent cells.
Abstract: SUMMARY In both silent and spontaneously active neurones of the snail Helix lucorum, depolarization and spikes were elicited by low-frequency (0-1 Hz) sinusoidal currents applied to the bath solution. Threshold voltage gradients had a range of 1-10 Vm" 1 , which is less than gradients in the nervous tissue during synchronous activation of the neurones. It is shown that the same neurone can generate spikes in response to opposite directions of polarizing currents. Thresholds of spontaneously active neurones to extracellular currents were significantly lower than thresholds of silent cells. A simple quantitative method for evaluation of the transmembrane voltage drop evoked by an electric field is presented. The role of neuronal branches in the response was studied by electrophysiological and morphological methods.
10 citations
Journal Article•
TL;DR: Functional consequences of selective reactions in neurons with different functional role are discussed and an increase of the action potential duration in sensory neurons can be the mechanism of the EPSP amplitude increase recorded in interneurons during application of serotonin.
Abstract: Bath application of serotonin was studied for its effect on the duration of action potentials in sensory neurons, interneurons and motoneurons participating in avoidance behaviour of snail. Serotonin application increased the action potential duration in sensory neurons, while in interneurons and motoneurons such changes were absent. An increase of the action potential duration in sensory neurons can be the mechanism of the EPSP amplitude increase recorded in interneurons during application of serotonin. Functional consequences of selective reactions in neurons with different functional role are discussed.
7 citations
TL;DR: It was deduced that serotonin makes a major contribution to establishing conditioned aversive reactions in the snail by increasing the amplitude of synaptic response to nerve stimulation in preparations in which stimulation was paired with serotonin application.
Abstract: Combined presentation of food and noxious electrical stimulation produced no response in snails injected 6–16 days previously with 5,7-dihydrooxytryptamine, which produces degeneration of serotoninergic nerve terminals and reduced serotonin synthesis, although a defense (aversive) response was observed in the control group. Application of serotonin to a preparation of the snail central nervous system (contained in a bath) was used as reinforcement during neurophysiological experiments. The amplitude of synaptic response to nerve stimulation increased significantly in preparations in which stimulation was paired with serotonin application. After 3–7 sets of twin stimuli consisting of serotonin application and applying a drop of juice to the chemoreceptive surface area of the skin, a spike response to the latter stimulus was produced. No such effects were seen in response to unpaired stimuli. It was deduced that serotonin makes a major contribution to establishing conditioned aversive reactions in the snail.
TL;DR: The cell process contributes toward creating considerable shifts of the membrane potential on the cell soma for a current density of 0.06–1.1 mA/cm2.
Abstract: 1
An extracellular electrical current creates on the cell membrane an induced potential, the magnitude of which increases with increasing length of the cell in the field
2
The effective length of the cell in the direction of the field is determined by the ratio of the resistances of the soma and of the processes directed along the field
3
The cell process contributes toward creating considerable shifts of the membrane potential on the cell soma for a current density of 006–11 mA/cm2