The Role of Intracellular Calcium in Changing of ElectricalCharacteristics of Premotor Interneurons in Intact Snails and Snails During Various Forms of Plasticity
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It was previously shown that both associative learning and the formation of long-term sensitization led to the increase in excitability of premotor interneurons of the defensive behavior of terrestrial snail Helix lucorum. In the present study, we analyzed the role of intracellular calcium ions in the maintenance of increased excitability in premotor interneurons of terrestrial snail after the formation of a conditioned defensive reflex. It was shown that the increase of the intracellular Ca2+ concentration after adding caffeine to the solution washing the nervous system of the mollusk led to a decrease of the threshold of action potential and to an increase of the critical level of depolarization without a change of the membrane potential of premotor interneurons in both intact and trained snails. The decrease of the intracellular Ca2+ concentration in premotor interneurons by the intracellular injection of (ethylene glycol-bis (2-aminoethylether)-N, N, N, N-tetraacetic acid) (EGTA) resulted in a significant increase of the threshold of generation of the action potential in intact snails. But the values of threshold of generation of the action potential in trained snails after injection of EGTA did not significantly differ from the values of studied parameters before injection. After application of the membrane-penetrating chelator, BAPTA-AM, the changes in the membrane and threshold potentials of premotor interneurons of intact and trained snails were not observed. Our results demonstrated that both the increase and decrease of intracellular Ca2+ concentration were not involved in maintaining the changes of membrane characteristics of premotor interneurons observed after associative learning.
KeywordsCalcium ions Associative learning Identified neurons Membrane potential Threshold potential Snail
The work is financially supported by Russian Foundation for Basic Research (grant 18-015-00274).
Compliance with Ethical Standards
Conflict of Interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Research Involving Humans and Animals Statement
All experimental procedures were carried out according with requirements of the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health, Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 and according with guidelines of Kazan Federal University. The terrestrial snails Helix lucorum were used for present experiments. Capture of animals in the wild nature was carried out by competent persons without any pain and distress (Article 9 of Directive 2010/63/EU). Snails were transported asleep and then stored asleep (Article 33 of Directive 2010/63/EU). Prior to the experiments snails were kept for no less than 2 weeks in a glass terrarium in a humid atmosphere at room temperature (Article 33 of Directive 2010/63/EU).
- 15.Kostyuk, P. G., Shmigal, A. V., Voitenko, N. V., Svichar, N. V., & Kostyuk, E. P. (1998). Endoplasmatic reticulum and mitochondria as elements of mechanism of intracellular signalization in nerve cell. Rossiiskii fiziologicheskii zurnal (Russian)., 84(10), 979–985.Google Scholar
- 17.Gainutdinov, K. L., Gainutdinova, T. H., & Chekmarev, L. Y. (1996). Changes of electrical characteristics of command neurons during defensive reflex conditioning in terrestrial snail. Zhurnal vysshei nervnoi deiatelnosti imeni I. P. Pavlova (Russian)., 46, 614–616.Google Scholar
- 18.Andrianov, V. V., Bogodvid, T. K., Deryabina, I. B., Golovchenko, A. N., Muranova, L. N., Tagirova, R. R., Vinarskaya, A. K., & Gainutdinov, K. L. (2015). Modulation of withdrawal reflex conditioning in snails by serotonin. Frontiers in Behavioral Neuroscience, 9(279), 1–12. https://doi.org/10.3389/fnbeh.2015.00279.Google Scholar
- 19.Gainutdinov, K. L., & Beregovoi, N. A. (1994). Long-term sensitization in snail: electrophysiological correlations in command neurons of avoidance behavior. Zhurnal vysshei nervnoi deiatelnosti imeni I. P. Pavlova (Russian), 44(2), 307–315.Google Scholar
- 20.Gainutdinov, K. L., Andrianov, V. V., Gainutdinova, T. K., & Tarasova, E. A. (2000). The electrical characteristics of command and motor neurons during acquisition of a conditioned withdrawal reflex and formation of long-term sensitization in snails. Neuroscience and Behavioral Physiology, 30(1), 81–88.CrossRefGoogle Scholar
- 21.Khodorov, B. I. (1974). The problem of excitability. Electrical excitability and ionic permeability of the nerve membrane (p. 301). New York: Plenum Press.Google Scholar
- 22.Kostyuk, P. G. (1992). Calcium ions in nerve cell function (p. 228). Oxford Neuroscience Series.Google Scholar
- 23.Silant'eva, D. I., Andrianov, V. V., Gainutdinova, T. K., Gainutdinov, K. L., & Pleshchinskii, I. N. (2006). The effects of changes in extracellular calcium concentrations on the electrical properties of command neurons after acquisition of a defensive conditioned reflex in snails. Neuroscience and Behavioral Physiology., 36(3), 209–212.CrossRefGoogle Scholar
- 24.Balaban, P. M., Zakharov, I. S. (1992). Learning and development – bases of two phenomena. M.: Nauka (Russian). 151.Google Scholar
- 35.Alkon, D. L. (1984). Changes of membrane currents during learning. The Journal of Experimental Biology, 112, 95–112.Google Scholar
- 36.Gainutdinov, K. L., Andrianov, V. V., & Gainutdinova, T. K. (2011). Changes of the neuronal membrane excitability as cellular mechanisms of learning and memory. Uspekhi Physiologicheskikh Nauk (Russian)., 42, 33–52.Google Scholar