Acute administration of a permeant analog of cAMP and a phosphodiesterase inhibitor improve long-term habituation in the crab Chasmagnathus

A shadow passing overhead acts as a danger stimulus and elicits an escape response in the crab Chasmagnathus that habituates promptly and for a long period. Robust retention is shown at 24 h after 15 trials of shadow presentation or at 120 h after 30 trials, but no significant retention is disclosed...

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Autores principales: Romano, A., Delorenzi, A., Pedreira, M.E., Tomsic, D., Maldonado, H.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01664328_v75_n1-2_p119_Romano
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Sumario:A shadow passing overhead acts as a danger stimulus and elicits an escape response in the crab Chasmagnathus that habituates promptly and for a long period. Robust retention is shown at 24 h after 15 trials of shadow presentation or at 120 h after 30 trials, but no significant retention is disclosed at 24 h after 5 trials or at 72 h after 15. A cocktail of the cAMP membrane permeable analog 8-(4-chlorophenylthio)-cAMP (CPT-cAMP), plus the phosphodiesterase inhibitor isobutyl methylxanthine (IBMX), was given by systemic administration. Pretraining injection of the cocktail (25 or 50 μM, 15 min before a 5-trial session) failed to affect short-term habituation, but induced significant retention when tested at 24 h. This facilitatory effect was not shown when a lower dose (5 μM) was used. A pest-training injection of 25 μM, immediately after a 5- or 15-trial session, induced retention when tested at 24 or 72 h, respectively. Thus, the administration of CPT-cAMP + IBMX during acquisition of a habituated response or immediately after, improves long-term habituation, a result supporting the view that an increase in the cAMP level is one of the steps in long-term memory consolidation.