Involvement of hippocampal AMPA glutamate receptor changes and the cAMP/protein kinase A/CREB-P signalling pathway in memory consolidation of an avoidance task in rats.
Training in step-down inhibitory avoidance (0.3-mA footshock) is followed by biochemical changes in rat hippocampus that strongly suggest an involvement of quantitative changes in glutamate AMPA receptors, followed by changes in the dopamine D1 receptor/cAMP/ protein kinase A (PKA)/CREB-P signalling pathway in memory consolidation. AMPA binding to its receptor and levels of the AMPA receptor-specific subunit GluR1 increase in the hippocampus within the first 3 h after training (20-70%). Binding of the specific D1 receptor ligand, SCH23390, and cAMP levels increase within 3 or 6 h after training (30-100%). PKA activity and CREB-P levels show two peaks: a 35-40% increase 0 h after training, and a second increase 3-6 h later (35-60%). The results correlate with pharmacological findings showing an early post-training involvement of AMPA receptors, and a late involvement of the D1/cAMP/PKA/CREB-P pathway in memory consolidation of this task.
Bernabeu
R
R
Instituto de Biología Celular, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Cammarota
M
M
Izquierdo
I
I
Medina
J H
JH
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D006624:Hippocampus / Q000737:chemistry*; D008568:Memory / Q000502:physiology*; D051381:Rats; D018091:Receptors, AMPA / Q000502:physiology*; D017470:Receptors, Glutamate / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
D017362:Cyclic AMP Response Element-Binding Protein; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; D017868:Cyclic AMP-Dependent Protein Kinases