IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Open field exposure ?prevents? amnesia caused by blockade of either NMDA glutamate receptors or cholinergic muscarinic receptors in the juvenile and adult rat
Autor/es:
M SNITCOFSKY; N COLETTIS; E KORNISIUK; M CERCATO; BAEZ V; A I AGUIRRE; D JERUSALINSKY
Lugar:
Huerta Grande
Reunión:
Congreso; XXVIII Congreso Anual SAN; 2013
Institución organizadora:
SAN
Resumen:
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Muscarinic
receptors (MAChR) or NMDA receptors (NMDAR) antagonism produced
amnesia of an inhibitory avoidance (IA) to a mild footshock in the
rat. We studied a previous open field (OF) exposure effect on adult
and juvenile rats´ performance in IA, when either MAChR or NMDAR
were blocked. Adult rats were to 1 or 2 OF sessions and trained in
IA; the muscarinic antagonist scopolamine was immediately injected
intrahippocampus (IH) and the IA long term memory (LTM) was assessed
24 h later: They expressed an IA LTM, while those not exposed to the
OF were amnesic. Both adult and juvenile rats previously exposed to
the OF showed an IA LTM, even though they received an intraperitoneal
(IP) injection of scopolamine before IA training. It was reported an
increase in hippocampal ACh release during and after OF exploration
and reexposure. This increase could contribute to "prepare the
substrate" (metaplasticity?) for synaptic plasticity, which
would result in IA LTM.
The
blockade of hippocampal NMDAR channel with MK-801 during IA
consolidation, though not during its acquisition in adult rats,
caused amnesia, which was prevented by 2 OF sessions before IA
training. Instead, IP MK-801 before IA training was amnesic in
juvenile rats and this amnesia was also prevented by previous OF
exposure. Based on these results and on recent findings of our lab
(see Baez et al, SAN, 2013), we hypothesize that the OF substantially
modifies NMDARs, facilitating synaptic plasticity and memory
formation.