Abstract
Experiments were carried out on isolated neurons of the thalamic nucleus lateralis dorsalis (LD) from 12-day-old rats. According to the morphological characteristics, LD neurons were classified as relay thalamo-cortical units and interneurons. The concentration of free Ca2+ ions in the cytoplasm ([Ca2+] i ) was measured by a fluorescent calcium indicator, fura-2AM. Application of 30 mM caffeine caused a transient change in the [Ca2+] i in 8 of 15 and in 6 of 11 of the thalamo-cortical units and interneurons under study, respectively. After stimulation of a cell with application of 50 mM KCl, a caffeine-induced increase in the [Ca2+] i was observed in all tested neurons. To study the contribution of Ca2+-induced Ca2+ release (CICR) to the calcium transient evoked by depolarization of the neuronal membrane, caffeine in a subthreshold concentration was pre-applied. After 50 mM KCl had been added to the medium following pre-application of 0.5 mM caffeine, the calcium transient amplitude in thalamo-cortical neurons increased by 51 ± 7% (n = 16). In interneurons this effect was not observed (n = 11). The data obtained allow us to hypothesize that CICR contributes to the depolarization-evoked calcium transient only in the relay (thalamo-cortical) neurons. Differences in the pattern of calcium signalling, which were detected in two types of neurons of the thalamic LD, can be a factor determining distinctions in the physiological characteristics of these neurons.
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REFERENCES
É. S. Moniava, Effects of The Thalamic Nuclei on the Brain Activity [in Russian], Metsniereba, Tbilisi (1985).
F. N. Serkov and V. N. Kazakov, Neurophysiology of the Thalamus [in Russian], Naukova Dumka, Kyiv (1980).
M. Steriade and R. R. Llinas, “The functional states of the thala-mus and the associated neuronal interplay,” Physiol. Rev., 68, 649-742 (1988).
P. G. Kostyuk, Calcium Ions in Nerve Cell Function, Oxford Univ. Press, Oxford, New York, Tokyo (1992).
A. Shmigol, A. Verkhratsky, and G. Isenberg, “Calcium-induced calcium release in rat sensory neurones,” J. Physiol., 489, No. 3, 627-636 (1995).
S. Kirischuk, V. Matiash, A. Kulik, et al., “Activation of P2-puri-no, α1-adreno and H1-histamine receptors triggers cytoplasmic calcium signalling in cerebellar Purkinje neurons,” Neuroscience, 73, 643-647 (1996).
G. Grynkiewicz, M. Poenie, and R.Y. Tsien, “A new generation of Ca2+ indicators with greatly improved fluorescent properties,” J. Biol. Chem., 260, 3440-3450 (1985).
A. Shmigol, N. Svichar, P. Kostyuk, and A. Verkhratsky, “Gradual caffeine-induced Ca2+ release in mouse dorsal root ganglion neurons is controlled by cytoplasmic and luminal Ca2+,” Neuroscience, 73, No. 4, 1061-1067 (1996).
P. B. Simpson, R. A. J. Chaliss, and S.R. Nahorski, “Involvement of intracellular stores in the Ca2+ responses to N-methyl-D-aspar-tate and depolarization in cerebellar granule cells,” J. Neurochem., 61, 760-763 (1993).
A. Galione, “Cyclic ADP-ribose: a new way to control calcium,” Science, 259, 325-326 (1993).
T. Budde, F. Sieg, K. H. Braunewell, et al., “Ca 2+-induced Ca2+ release supports the relay mode of activity in thalamocortical cells,” Neuron, 26, No. 2, 483-492 (2000).
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Shutov, L.P., Kruglikov, I.A. & Voitenko, N.V. Participation of Intracellular Ca2+ Stores in Ca2+ Signalling in Neurons of the Thalamic Laterodorsal Nucleus of Rats. Neurophysiology 33, 94–97 (2001). https://doi.org/10.1023/A:1012328109318
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DOI: https://doi.org/10.1023/A:1012328109318