Effect of radicicol infusion on the Src tyrosine kinase activity of rat hippocampus before and after training in an inhibitory avoidance task.
The participation of protein serine/threonine kinases in memory formation and retrieval is well established. In contrast, relatively little is known on the role of protein tyrosine kinases (PTKs). Previous work showed that intra-hippocampal infusion of the Src-PTK inhibitor radicicol inhibits memory acquisition, consolidation, and retrieval of one-trial step-down inhibitory avoidance task. In this study, we investigated the possible interaction between levels of Src-PTK activity in hippocampus and memory acquisition, formation, and retrieval of this task. Radicicol (0.5 microg/ml) was infused into the CA1 region of the hippocampus of rats trained in a one-trial step-down inhibitory avoidance task. Radicicol infused 15 min before training decreased Src-PTK activity, as measured 0, 1.5, and 24 h after training, and impaired memory acquisition of the task. When given immediately after training, there was a decrease in Src-PTK activity 1.5 h, but not 0 or 24 h after training. This treatment depressed memory consolidation. Radicicol infused into CA1 10 min prior to retrieval testing inhibited hippocampal Src-PTK activity, as measured immediately after the test session. The results suggest that Src-PTKs participate in memory acquisition, consolidation, and retrieval processes, but the timing of the role of the enzyme is different in each case.
Pereira
Patrícia
P
Centro de Memória, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcellos 2600, anexo, Porto Alegre, 90035-003, RS, Brazil. patipere@yahoo.com.br
Vinadé
Elsa
E
Rodrigues
Letícia
L
De David e Silva
Tiago L
TL
Ardenghi
Patrícia
P
da Silva Brum
Lucimar Filot
LF
Gonçalves
Carlos Alberto
CA
Izquierdo
Iván
I
D000818:Animals; D001362:Avoidance Learning; D004791:Enzyme Inhibitors / Q000378:metabolism; D006624:Hippocampus / Q000201:enzymology*; D018942:Macrolides / Q000378:metabolism; D008297:Male; D008568:Memory / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D004791:Enzyme Inhibitors; D018942:Macrolides; D019061:src-Family Kinases; C035359:monorden