title: Synaptic plasticity during recovery from permanent occlusion of the middle cerebral artery.
abstract: Synaptic rearrangements in the peri-infarct regions are believed to contribute to the partial recovery of function that takes place after stroke. Here, we performed neurophysiological recordings from single neurons of rats with permanent occlusion of the middle cerebral artery (pMCAO) during the resolution of their neurological deficits. Our results show that complex and dynamic changes of glutamate transmission in the peri-infarct area parallel the recovery from brain infarct. We have observed that frequency and duration of spontaneous glutamate-mediated synaptic events were markedly increased in striatal neurons during the early phase of the recovery (3 days after pMCAO), due to potentiation of both NMDA (N-methyl-d-aspartate) and non-NMDA receptor-mediated transmission. In the late phase of recovery (7 days after pMCAO), glutamate transmission was still enhanced because of a selective facilitation of non-NMDA receptor-mediated transmission. Spiny projection neurons but not aspiny interneurons underwent detectable changes of synaptic excitability in the striatum following pMCAO, indicating that the process of neuronal adaptation after focal brain ischemia is cell-type-specific. Our results provide a synaptic correlate of the long-lasting brain hyperexcitability mediating recovery described with noninvasive neurophysiological approaches.
authors.affiliation: Clinica Neurologica, Dipartimento di Neuroscienze, Università Tor Vergata, Rome, Italy. centonze@uniroma2.it
authors.forename: Diego
authors.initials: D
authors.lastname: Centonze
authors.forename: Silvia
authors.initials: S
authors.lastname: Rossi
authors.forename: Anna
authors.initials: A
authors.lastname: Tortiglione
authors.forename: Barbara
authors.initials: B
authors.lastname: Picconi
authors.forename: Chiara
authors.initials: C
authors.lastname: Prosperetti
authors.forename: Valentina
authors.initials: V
authors.lastname: De Chiara
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bernardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Calabresi
mesh_terms: D000818:Animals; D003342:Corpus Striatum / Q000473:pathology / Q000503:physiopathology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D018698:Glutamic Acid / Q000502:physiology; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology* / Q000503:physiopathology*; D007395:Interneurons / Q000473:pathology / Q000502:physiology; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid