Interaction between M1-muscarinic and glutamatergic NMDA receptors on an inhibitory avoidance task.
It has been demonstrated that MK-801 potentiates the effects of the non-selective muscarinic antagonist scopolamine on memory in rats. In this study, we investigated the role of the M1-muscarinic receptor in this interaction, by administering different doses of dicyclomine (DIC) and MK-801 in combination to male Wistar rats before training on the inhibitory avoidance task. MK-801 and DIC in sub-effective doses were administered in combination. It was observed that MK-801 at a dose of 0.1125 mg/kg with a sub-effective dose of 8 mg/kg of DIC significantly impaired the retention test when compared with saline-treated animals, i.e. MK-801 potentiated the effects of dicyclomine on memory impairment. Our results suggest an important role for the M1-muscarinic receptor in the synergistic interaction between cholinergic muscarinic and glutamatergic NMDA receptors, which is in line with the findings that the interactive modulation between these two neurotransmitters systems constitutes an important mechanism in cognitive functions.
Monteiro Moreira
Karin
K
Universidade Federal de São Paulo, Departamento de Psicobiologia, Rua Napoleão de Barros 925, CEP 04024-002, São Paulo, SP, Brazil.
Lima Ferreira
Tatiana
T
Vecchio Fornari
Raquel
R
Perez Figueredo
Larissa Zeggio
LZ
Menezes Oliveira
Maria Gabriela
MG
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000502:physiology; D004025:Dicyclomine / Q000494:pharmacology; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043643:Receptor, Muscarinic M1 / Q000037:antagonists & inhibitors / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects*
D018691:Excitatory Amino Acid Antagonists; D018727:Muscarinic Antagonists; D043643:Receptor, Muscarinic M1; D016194:Receptors, N-Methyl-D-Aspartate; D004025:Dicyclomine; D016291:Dizocilpine Maleate