Effects of extracellular Ca and Ca-channel blockers on A-currents in snail brain neurons

¹Department of Comparative Physiology, József Attila University, Szeged, Hungary.

|January 1, 1987

Abstract:

A study was made to characterize the extracellular Ca sensitivity of the A-currents in identified neurons (LPa2, 3) of the snail, Helix pomatia L. The characteristics and voltage-dependence of activation and inactivation of isolated A-currents were examined under voltage clamp in normal, low Ca and high Ca solutions. Modification of the extracellular Ca concentration between 0 and 28 mM caused a dose-dependent attenuation of the amplitude of A-currents and alteration of the current kinetics. Anorganic Ca-channel blockers (Ni, Cd, La) also decreased the amplitude of A-currents in a dose-dependent reversible manner, but the organic Ca-channel blocker verapamil did not influence the A-current amplitude. An analysis of the Hill plots of Ca and Ni dose-inhibition data showed similar values for the Hill constants (nH) with 1.3 and 1.2 respectively. Lowering the potassium concentration in the saline increased the amplitude of A-currents, while Na-deficiency slightly decreased the amplitude of A-currents. Tetraethylammonium (TEA) modulated the amplitude and kinetics of A-currents and 4-aminopyridine (4-AP) blocked all components of the A-currents.

Related Experiment Videos

Effects of extracellular Ca and Ca-channel blockers on A-currents in snail brain neurons

Related Concept Videos

pH-dependent actions of aluminum on voltage-activated sodium currents in snail neurons.

Mytilus inhibitory peptides (MIP) in the central and peripheral nervous system of the pulmonate gastropods, Lymnaea stagnalis and Helix pomatia: distribution and physiological actions.

Time-dependent actions of aluminates on membrane and action potentials of snail neurons.

The possible roles of the monoaminergic system in the feeding of the snail Helix pomatia.

Pre- and postsynaptic effects of eugenol and related compounds on Helix pomatia L. neurons.

The organization of serotonin-, dopamine-, and FMRFamide-containing neuronal elements and their possible role in the regulation of spontaneous contraction of the gastrointestinal tract in the snail Helix pomatia.

An improved light dark box test by using a real-time video tracking system.

The application of Magnetic Resonance Imaging (mri) to the examination of plant tissues and water barriers.

In vitro pharmacological effects of Astragalus eremophilus and Melilotus parviflora.

Comparative toxicity evaluation of targeted anticancer therapeutics in embryonic zebrafish and sea urchin models.

Inhibition of the formation of amyloid-like fibrils with spices, especially cloves.

Effects of drought stress on hybrids of Vigna radiata at germination stage.

Multilayered interplay between the cGAS-STING pathway and autophagy.

Regional anesthesia after spinal cord injury attenuates behavioral loss, hemorrhage, and cell death.

Minimally Invasive Lumbar Fusion Is Associated with Lower Reoperation for Adjacent Segment Disease and Improved Patient-Reported Outcomes Compared with Open Surgery.

The Current Status, Prognosis, and Influencing Factors of Emergency Surgery in Patients With Facial Trauma in Intoxicated State.

Secondary CT Signs of Occult Craniofacial Fractures in Patients With Head and Facial Trauma.

Performance evaluation of a direct chemiluminescence assay for 25-hydroxyvitamin D and its application in assessing vitamin D status among reproductive-age women in southeastern China.

Related Experiment Videos

Effects of extracellular Ca and Ca-channel blockers on A-currents in snail brain neurons

Abstract:

Related Concept Videos

Related Articles