title: Glutamate levels and transport in cat (Felis catus) area 17 during cortical reorganization following binocular retinal lesions.
abstract: Glutamate is known to play a crucial role in the topographic reorganization of visual cortex after the induction of binocular central retinal lesions. In this study we investigated the possible involvement of the glial high-affinity Na+/K+-dependent glutamate transporters in cortical plasticity using western blotting and intracortical microdialysis. Basal extracellular glutamate levels and the re-uptake activity for glutamate have been determined by comparing the extracellular glutamate concentration before and during the blockage of glutamate removal from the synaptic cleft with the potent transporter inhibitor l-trans-pyrrolidine-3,4-dicarboxylic acid. In cats with central retinal lesions we observed increased basal extracellular glutamate concentrations together with a decreased re-uptake activity in non-deprived, peripheral area 17, compared with the sensory-deprived, central cortex of the same animal as well as the topographically matching regions of area 17 in normal subjects. Western blotting experiments revealed a parallel decrease in the expression level of the glial glutamate transporter proteins GLT-1 and GLAST in non-deprived cortex compared with sensory-deprived cortex of lesion cats and the corresponding regions of area 17 of normal subjects. This study shows that partial sensory deprivation of the visual cortex affects the removal of glutamate from the synaptic cleft and implicates a role for glial-neuronal interactions in adult brain plasticity.
authors.affiliation: Laboratory of Neuroendocrinology and Immunological Biotechnology, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Ann
authors.initials: A
authors.lastname: Massie
authors.forename: Lieselotte
authors.initials: L
authors.lastname: Cnops
authors.forename: Sandy
authors.initials: S
authors.lastname: Jacobs
authors.forename: Katrien
authors.initials: K
authors.lastname: Van Damme
authors.forename: Erik
authors.initials: E
authors.lastname: Vandenbussche
authors.forename: Ulf T
authors.initials: UT
authors.lastname: Eysel
authors.forename: Frans
authors.initials: F
authors.lastname: Vandesande
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Arckens
mesh_terms: D027322:Amino Acid Transport System X-AG / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D015153:Blotting, Western; D002415:Cats; D004268:DNA-Binding Proteins / Q000235:genetics; D003998:Dicarboxylic Acids / Q000494:pharmacology; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism; D005110:Extracellular Space / Q000737:chemistry / Q000378:metabolism; D018698:Glutamic Acid / Q000032:analysis / Q000378:metabolism*; D017551:Microdialysis; D009473:Neuronal Plasticity / Q000502:physiology*; D011759:Pyrrolidines / Q000494:pharmacology; D012160:Retina / Q000502:physiology*; D012683:Sensory Deprivation / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D015348:Vision, Binocular / Q000502:physiology; D014793:Visual Cortex / Q000187:drug effects / Q000378:metabolism*
chemical_list: D027322:Amino Acid Transport System X-AG; D004268:DNA-Binding Proteins; D003998:Dicarboxylic Acids; D027342:Excitatory Amino Acid Transporter 2; D011759:Pyrrolidines; D014157:Transcription Factors; C108501:pyrrolidine-3,4-dicarboxylic acid; D018698:Glutamic Acid