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N‐methyl‐d‐aspartate receptor‐mediated, calcium‐induced calcium release in rat dentate gyrus/CA4 in vivo
Author(s) -
Lazarewicz Jerzy W.,
Rybkowski Waldemar,
Ziembowicz Apolonia,
Alaraj Mohol,
Sadowski Marcin,
Wegiel Jerzy,
Wisniewski Henryk M.
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980101)51:1<76::aid-jnr8>3.0.co;2-i
Subject(s) - nmda receptor , ryanodine receptor , microdialysis , chemistry , calcium , receptor , biophysics , glutamate receptor , dantrolene , in vivo , microbiology and biotechnology , biology , endocrinology , medicine , biochemistry , extracellular , organic chemistry
Previously, by using in vivo microdialysis, we demonstrated a huge release of 45 Ca 2+ from prelabeled tissues to dialysate that was evoked by application of N ‐methyl‐d‐aspartate (NMDA) to the rat dentate gyrus (DG) and sector 4 of the cornu ammonis. To establish the mechanism of this phenomenon, in the present study, we characterized its NMDA receptor dependence, investigated the mechanism of 45 Ca 2+ removal from the cells, and evaluated the possible involvement of calcium‐binding protein calbindin D 28k and of ryanodine receptors. Microdialysis experiments demonstrated a dose‐response relation between NMDA and 45 Ca 2+ release and sensitivity of this phenomenon to inhibition by 10 μMK‐801 and 5 mm 5‐( N,N ‐dimethyl)‐amiloride, thus indicating the NMDA receptor dependence and a role of Na + /Ca 2+ exchanger in mediating 45 Ca 2+ release from cells. Immunocytochemical experiments confirmed that DG granule cells in the investigated inbred rat strain are strongly calbindin D 28k ‐immunopositive, indicating probable involvement of this protein. However, micro‐dialysis studies demonstrated that NMDA‐evoked 45 Ca 2+ release was suppressed by 100 μdantrolene and 250 μryanodine, whereas 50 μryanodine stimulated this effect. This points to a key role in the investigated phenomenon of calcium‐induced calcium release (CICR) via ryanodine receptors. To our knowledge, this is the first in vivo demonstration of NMDA‐evoked CICR. We postulate the usefulness of microdialysis in such studies.