Please use this identifier to cite or link to this item:
Title: Presynaptic kainate receptors modulating glutamatergic transmission in the rat hippocampus are inhibited by arachidonic acid
Authors: Cunha, Rodrigo A. 
Ribeiro, J. A. 
Malva, João O. 
Keywords: Kainate; Arachidonic acid; Hippocampus; Synaptic transmission; Nerve terminals; Glutamate release; Binding
Issue Date: 2004
Citation: Neurochemistry International. 44:5 (2004) 371-379
Abstract: Kainate receptors are ionotropic glutamate receptors located postsynaptically, mediating frequency-dependent transmission, and presynaptically, modulating transmitter release. In contrast to the excitatory postsynaptic kainate receptors, presynaptic kainate receptor can also be inhibitory and their effects may involve a metabotropic action. Arachidonic acid (AA) modulates most ionotropic receptors, in particular postsynaptic kainate receptor-mediated currents. To further explore differences between pre- and postsynaptic kainate receptors, we tested if presynaptic kainate receptors are affected by AA. Kainate (0.3-3 [mu]M) and the kainate receptor agonist, domoate (60-300 nM), inhibited by 19-54% the field excitatory postsynaptic potential (fEPSP) slope in rat CA1 hippocampus, and increased by 12-32% paired-pulse facilitation (PPF). AA (10 [mu]M) attenuated by 37-72% and by 62-66% the domoate (60-300 nM)-induced fEPSP inhibition and paired-pulse facilitation increase, respectively. This inhibition by AA was unaffected by cyclo- and lipo-oxygenase inhibitors, indomethacin (20 [mu]M) and nordihydroguaiaretic acid (NDGA, 50 [mu]M) or by the free radical scavenger, N-acetyl--cysteine (0.5 mM). The K+ (20 mM)-evoked release of [3H]glutamate from superfused hippocampal synaptosomes was inhibited by 18-39% by domoate (1-10 [mu]M), an effect attenuated by 35-63% by AA (10 [mu]M). Finally, the KD (40-55 nM) of the kainate receptor agonist [3H]-(2S,4R)-4-methylglutamate ([3H]MGA) (0.3-120 nM) binding to hippocampal synaptosomal membranes was increased by 151-329% by AA (1-10 [mu]M). These results indicate that AA directly inhibits presynaptic kainate receptor controlling glutamate release in the CA1 area of the rat hippocampus.
DOI: 10.1016/S0197-0186(03)00167-0
Rights: openAccess
Appears in Collections:FMUC Medicina - Artigos em Revistas Internacionais

Files in This Item:
File Description SizeFormat
file311cfd16de6f4d41a62150aae249ff28.pdf174.37 kBAdobe PDFView/Open
Show full item record


checked on Aug 2, 2022

Page view(s) 50

checked on Aug 16, 2022


checked on Aug 16, 2022

Google ScholarTM




Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.