Long-term potentiation of neuronal glutamate transporters.
Persistent, use-dependent modulation of synaptic strength has been demonstrated for fast synaptic transmission mediated by glutamate and has been hypothesized to underlie persistent behavioral changes ranging from memory to addiction. Glutamate released at synapses is sequestered by the action of excitatory amino acid transporters (EAATs) in glia and postsynaptic neurons. So, the efficacy of glutamate transporter function is crucial for regulating glutamate spillover to adjacent presynaptic and postsynaptic receptors and the consequent induction of plastic or excitotoxic processes. Here, we report that tetanic stimulation of cerebellar climbing fiber-Purkinje cell synapses results in long-term potentiation (LTP) of a climbing fiber-evoked glutamate transporter current recorded in Purkinje cells. This LTP is postsynaptically expressed and requires activation of an mGluR1/PKC cascade. Together with a simultaneously induced long-term depression (LTD) of postsynaptic AMPA receptors, this might reflect an integrated antiexcitotoxic cellular response to strong climbing fiber synaptic activation, as occurs following an ischemic episode.
Shen
Ying
Y
Department of Neuroscience, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, USA.
Linden
David J
DJ
D027322:Amino Acid Transport System X-AG / Q000037:antagonists & inhibitors / Q000502:physiology*; D000818:Animals; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D027322:Amino Acid Transport System X-AG; D011810:Quinoxalines; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline