title: Synaptosomal glutamate release and uptake in mice lacking the cellular prion protein.
abstract: Glutamate plays a central role in the fast excitatory synaptic transmission and is a key neurotransmitter involved in several neurophysiological processes. Glutamate levels on the synaptic cleft are related to neural excitability, neuroplasticity, and neuronal damage associated with excitotoxicity. Mice lacking the cellular prion protein (PrP(c)) gene (Prnp) present a decreased astrocytic glutamate uptake in cultures, higher neuronal excitability in vitro and sensitivity to pro-convulsant drugs in vivo, and age-dependent memory impairment. Here, we investigate if PrP(c) might be involved in neuronal uptake and release of glutamate. For this purpose, we compared synaptosomal preparations from the cerebral cortex, entorhinal cortex, hippocampus, cerebellum, and olfactory bulb of 3- or 9-month-old PrP(c) null mice and with respective wild-type controls. Although we observed differences in synaptosomal glutamate release and uptake regarding the age of mice and the brain structure studied, these differences were similar for PrP(c) null mice and their respective wild-type controls. Therefore, despite a possible correlation between neuronal glutamate transporters, excitability, and neuronal damage, our results suggest that PrP(c) expression is not critical for neuronal glutamate transport.
authors.affiliation: Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Trindade, 88040-900 Florianópolis, SC, Brasil.
authors.forename: Maria Emília
authors.initials: ME
authors.lastname: Thais
authors.forename: Cristiane L
authors.initials: CL
authors.lastname: Carqueja
authors.forename: Tiago G
authors.initials: TG
authors.lastname: Santos
authors.forename: Ronan V
authors.initials: RV
authors.lastname: Silva
authors.forename: Ellen
authors.initials: E
authors.lastname: Stroeh
authors.forename: Ronny S
authors.initials: RS
authors.lastname: Machado
authors.forename: Daniela O
authors.initials: DO
authors.lastname: Wahlheim
authors.forename: Marino M
authors.initials: MM
authors.lastname: Bianchin
authors.forename: Américo C
authors.initials: AC
authors.lastname: Sakamoto
authors.forename: Ricardo R
authors.initials: RR
authors.lastname: Brentani
authors.forename: Vilma R
authors.initials: VR
authors.lastname: Martins
authors.forename: Roger
authors.initials: R
authors.lastname: Walz
authors.forename: Carla I
authors.initials: CI
authors.lastname: Tasca
mesh_terms: D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D051379:Mice; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D011328:Prions; D018698:Glutamic Acid