title: Habituation to an open field alters ecto-nucleotidase activities in rat hippocampal synaptosomes.
abstract: ATP and adenosine may play a role in the mechanisms of synaptic plasticity and memory formation. Previous studies have shown that ecto-nucleotidase activities are altered during memory consolidation of an aversive task named step-down inhibitory avoidance. Here we investigate ecto-nucleotidase activities in hippocampal synaptosomes of rats submitted to training and test sessions of habituation to open field, which is one of the most elementary forms of learning. There were no significant alterations on ATP, ADP and AMP hydrolysis immediately after the training session. However, immediately after the test session (0min), there was a significant increase of ATP hydrolysis (61%), but not of ADP and AMP hydrolysis. Sixty minutes after the test session, a significant increase of NTPDase (75% and 60.5% for ATP and ADP hydrolysis, respectively) and ecto-5'-nucleotidase (40%) activities was observed. This study reveals the involvement of ecto-nucleotidase activities in different learning paradigms during memory processing.
authors.affiliation: Laboratório de Neuroquímica e Psicofarmacologia, Departamento de Biologia Celular e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul. Avenida Ipiranga, 6681, 90619-900 Porto Alegre, RS, Brazil.
authors.forename: Eduardo Luiz
authors.initials: EL
authors.lastname: Pedrazza
authors.forename: Gustavo Pelicioli
authors.initials: GP
authors.lastname: Riboldi
authors.forename: Grace Schenatto
authors.initials: GS
authors.lastname: Pereira
authors.forename: Iván
authors.initials: I
authors.lastname: Izquierdo
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D004789:Enzyme Activation / Q000502:physiology; D005106:Exploratory Behavior / Q000502:physiology*; D006185:Habituation, Psychophysiologic; D006624:Hippocampus / Q000648:ultrastructure*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000201:enzymology*; D013997:Time Factors
chemical_list: D000251:Adenosine Triphosphatases; C027201:ectoATPase