Off-line concomitant release of dopamine and glutamate involvement in taste memory consolidation.
It has been postulated that memory consolidation process requires post-learning molecular changes that will support long-term experiences. In the present study, we assessed with in vivo microdialysis and capillary electrophoresis whether such changes involve the release of neurotransmitters at post-acquisition stages. Using conditioned taste aversion paradigm we observed spontaneous off-line (i.e. in absence of stimulation) dopamine and glutamate reactivation within the insular cortex about 45 min after the stimuli association. These increments did not appear in control groups that were unable to acquire the task, and it seems to be dependent on amygdala activity since its reversible inactivation by tetrodotoxin impaired cortical off-line release of both neurotransmitters and memory consolidation. In addition, blockade of dopaminergic D1 and/or NMDA receptors before the off-line activity impaired long- but not short-term memory. These results suggest that off-line extracellular increments of glutamate and dopamine have a significant functional role in consolidation of taste memory.
Guzmán-Ramos
Kioko
K
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F 04510, México.
Osorio-Gómez
Daniel
D
Moreno-Castilla
Perla
P
Bermúdez-Rattoni
Federico
F
D000679:Amygdala / Q000502:physiology; D000818:Animals; D001362:Avoidance Learning; D001552:Benzazepines / Q000494:pharmacology; D002540:Cerebral Cortex / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004298:Dopamine / Q000378:metabolism*; D019075:Electrophoresis, Capillary; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D008568:Memory; D017551:Microdialysis; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013649:Taste; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D001552:Benzazepines; D018377:Neurotransmitter Agents; D017447:Receptors, Dopamine D1; D016194:Receptors, N-Methyl-D-Aspartate; C534628:SCH 23390; D018698:Glutamic Acid; C056639:2-amino-5-phosphopentanoic acid; D017868:Cyclic AMP-Dependent Protein Kinases; D014633:Valine; D004298:Dopamine