Genetic and pharmacological studies of GluR5 modulation of inhibitory synaptic transmission in the anterior cingulate cortex of adult mice.
In the anterior cingulate cortex (ACC), GluR5-containing kainate receptor mediated the small portion of excitatory postsynaptic current. However, little is known about its role in modulation of neurotransmitter release in this brain region. In the present study, we address this question by using selective GluR5 agonist and antagonist, as well as GluR5(-/-) mice. Our results showed that activation of GluR5 induced action potential-dependent GABA release, which is also required for the activation of voltage-dependent calcium channel and Ca(2+) influx. The effect of GluR5 activation is selective to the GABAergic, but not glutamatergic synaptic transmission. Endogenous activation of GluR5 also enhanced GABA release to ACC pyramidal neurons and the corresponding postsynaptic tonic GABA current. Our results suggest the somatodendritic, but not presynaptic GluR5, in modulation of GABA release. The endogenous GluR5 activation and the subsequent tonic GABA current may play an inhibitory role in ACC-related brain functions.
Wu
Long-Jun
LJ
Department of Physiology, Faculty of Medicine, University of Toronto, Medical Science Building, Toronto, Ontario, Canada M5S 1A8.
Xu
Hui
H
Ren
Ming
M
Zhuo
Min
M
D000818:Animals; D002118:Calcium / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006179:Gyrus Cinguli / Q000166:cytology*; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009433:Neural Inhibition / Q000187:drug effects* / Q000235:genetics*; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology; D018092:Kainic Acid Receptors / Q000172:deficiency / Q000235:genetics*; D009435:Synaptic Transmission / Q000187:drug effects* / Q000235:genetics*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D002118:Calcium; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018092:Kainic Acid Receptors; D005680:gamma-Aminobutyric Acid