B-50/GAP-43 phosphorylation and PKC activity are increased in rat hippocampal synaptosomal membranes after an inhibitory avoidance training

Several lines of evidence indicate that protein kinase C (PKC) is involved in long-term potentiation (LTP) and in certain forms of learning. Recently, we found a learning-specific, time-dependent increase in [3H]phorbol dibutyrate binding to membrane-associated PKC in the hippocampus of rats subject...

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Detalles Bibliográficos
Autores principales: Cammarota, M., Paratcha, G., De Stein, M.L., Bernabeu, R., Izquierdo, I., Medina, J.H.
Formato: JOUR
Materias:
B-50/GAP-43
hippocampus
learning
memory
PKC
protein phosphorylation
1 (5 isoquinolinesulfonyl) 2 methylpiperazine
neuromodulin
phorbol dibutyrate
polymyxin B
protein kinase C
protein kinase C inhibitor
staurosporine derivative
tritium
animal cell
animal experiment
article
brain synaptosome
controlled study
enzyme activity
long term potentiation
male
nonhuman
priority journal
rat
synaptic membrane
task performance
training
Animalia
Bovinae
Tritium
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_03643190_v22_n4_p499_Cammarota
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Several lines of evidence indicate that protein kinase C (PKC) is involved in long-term potentiation (LTP) and in certain forms of learning. Recently, we found a learning-specific, time-dependent increase in [3H]phorbol dibutyrate binding to membrane-associated PKC in the hippocampus of rats subjected to an inhibitory avoidance task. Here we confirm and extend this observation, describing that a one trial inhibitory avoidance learning was associated with rapid and specific increases in B-50/GAP-43 phosphorylation in vitro and in PKC activity in hippocampal synaptosomal membranes. The increased phosphorylation of B-50/GAP-43 was seen at 30 rain (+35% relative to naive or shocked control groups), but not at 10 or 60 rain after training. This learning-associated increase in the phosphorylation of B-50/GAP-43 is mainly due to an increase in the activity of PKC. This is based on three different sets of data: 1) PKC activity increased by 24% in hippocampal synaptosomal membranes of rats sacrificed 30 min after training; 2) B-50/GAP-43 immunoblots revealed no changes in the amount of this protein among the different experimental groups; 3) phosphorylation assays, performed in the presence of bovine purified PKC or in the presence of the selective PKC inhibitor CGP 41231, exhibited no differences in B-50/GAP-43 phosphorylation between naive and trained animals. In conclusion, these results support the contention that hippocampal PKC participates in the early neural events of memory formation of an aversively-motivated learning task.

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