Metabotropic glutamate receptors and calcium signalling in dendrites of hippocampal CA1 neurones.
We have combined patch-clamp recording with confocal microscopy to investigate how the synaptic activation of metabotropic glutamate receptors (mGluRs) may participate in the modulation of intracellular free calcium (Ca2+) in the dendrites of single CA1 pyramidal neurones, within hippocampal slices. Tetanic stimulation (100 Hz, 1 sec) of the Schaffer collateral-commissural pathway led to a transient rise in Ca2+ in the dendrites of neurones voltage- clamped at -35 mV, as determined using the fluorescent indicator fluo-3. The specific mGluR antagonist (+)-alpha-methyl-4-carboxyphenylglycine (MCPG), applied at a concentration of 250 or 500 microM, reduced the size of the Ca2+ transient whilst either producing a small reduction or, more commonly, having no effect on the synaptic current evoked by the tetanus. These data suggest that the synaptic activation of mGluRs can contribute to Ca2+ signalling in hippocampal neurones.
Frenguelli
B G
BG
Department of Pharmacology, Medical School, University of Birmingham, Edgbaston, U.K.
Potier
B
B
Slater
N T
NT
Alford
S
S
Collingridge
G L
GL
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D003712:Dendrites / Q000187:drug effects*; D004558:Electric Stimulation; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects; D008856:Microscopy, Fluorescence; D009475:Neurons, Afferent / Q000187:drug effects*; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects
D018094:Receptors, Metabotropic Glutamate; D015763:2-Amino-5-phosphonovalerate; D002118:Calcium