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P2X 7 pre‐synaptic receptors in adult rat cerebrocortical nerve terminals: a role in ATP‐induced glutamate release
Author(s) -
Marcoli Manuela,
Cervetto Chiara,
Paluzzi Paola,
Guarnieri Stefania,
Alloisio Susanna,
Thellung Stefano,
Nobile Mario,
Maura Guido
Publication year - 2008
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2008.05322.x
Subject(s) - glutamate receptor , receptor , glutamatergic , biology , neuroscience , ion channel linked receptors , astrocyte , microbiology and biotechnology , extracellular , neuron , metabotropic glutamate receptor , central nervous system , biochemistry
Although growing evidence suggests that extracellular ATP might play roles in the control of astrocyte/neuron crosstalk in the CNS by acting on P2X 7 receptors, it is still unclear whether neuronal functions can be attributed to P2X 7 receptors. In the present paper, we investigate the location, pharmacological profile, and function of P2X 7 receptors on cerebrocortical nerve terminals freshly prepared from adult rats, by measuring glutamate release and calcium accumulation. The preparation chosen (purified synaptosomes) ensures negligible contamination of non‐neuronal cells and allows exposure of ‘nude’ release‐regulating pre‐synaptic receptors. To confirm the results obtained, we also carried out specific experiments on human embryonic kidney 293 cells which had been stably transfected with rat P2X 7 receptors. Together, our findings suggest that (i) P2X 7 receptors are present in a subpopulation of adult rat cerebrocortical nerve terminals; (ii) P2X 7 receptors are localized on glutamatergic nerve terminals; (iii) P2X 7 receptors play a significant role in ATP‐evoked glutamate efflux, which involves Ca 2+ ‐dependent vesicular release; and (iv) the P2X 7 receptor itself constitutes a significant Ca 2+ ‐independent mode of exit for glutamate.