Effects of activation and inhibition of cAMP-dependent protein kinase on long-term habituation in the crab Chasmagnathus

On sudden presentation of a danger stimulus, the crab Chasmagnathus elicits an escape response that habituates promptly and far a long period. We have previously reported that administration of a cAMP-permeable analog (CPT-cAMP) along with a phosphodiesterase inhibitor (IBMX) improves long-term habi...

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Detalles Bibliográficos
Autores principales: Romano, A., Locatelli, F., Delorenzi, A., Pedreira, M.E., Maldonado, H.
Formato: JOUR
Materias:
cAMP analog
Crustacea
Habituation
Learning
Long-term memory
Protein kinase A
cyclic AMP
cyclic AMP dependent protein kinase
cyclic AMP derivative
phosphodiesterase inhibitor
protein kinase inhibitor
animal experiment
animal tissue
article
behavior
brain tissue
controlled study
crab
habituation
long term memory
male
nonhuman
priority journal
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00068993_v735_n1_p131_Romano
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:On sudden presentation of a danger stimulus, the crab Chasmagnathus elicits an escape response that habituates promptly and far a long period. We have previously reported that administration of a cAMP-permeable analog (CPT-cAMP) along with a phosphodiesterase inhibitor (IBMX) improves long-term habituation (LTH). In present experiments we studied the effect of systemic administration of the protein kinase A (PKA) activator Sp-,5,6-DCl-cBIMPS and that of the PKA inhibitor Rp-8-Cl-cAMPS on LTH tested 24 h after a weak training protocol (5 trials of danger stimulus presentation) or a strong training protocol (15-30 trials), respectively. A 50 μl pre-training injection of 75 μM Sp-5,6-DCl-cBIMPS, and to a lesser degree of 25 μM, improved retention of the habituated response but not affect short-term habituation (STH). Like pre-training injection, post-training administration of Sp-5,6-DCl-cBIMPS proved to exert a facilitatory action on retention though with 75 μM dose only. Conversely, both pre- and post-training injection of 25 μM Rp-8-Cl-cAMPS impaired LTH without affecting STH. Thus, the PKA activator Sp-5,6-DCl-cBIMPS enables a weak training to produce LTH while the PKA inhibitor Rp-8-Cl-cAMPS impairs LTH when a strong training is given. Activation of crab PKA by Sp-5,6-DCl-cBIMPS and its inhibition by Rp-8-Cl-cAMPS were assessed using an in vitro PKA activity assay. These results provide independent evidences supporting the view that PKA plays a key role in long-term memory storage in this learning paradigm.

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