IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Hippocampal NMDA receptors are differentially involved in memory consolidation depending on their NR2 composition
Autor/es:
COLETTIS N; CHELI V,; SNITCOFSKY M.; BLANCO C; QUILLFEDT J; KORNISUIK E.; JERUSALINSKY D.
Lugar:
Búzios, RJ, Brasil
Reunión:
Congreso; I Congresso IBRO/LARC de Neurocièncias da América Latina, Caribe e Península Ibérica; 2008
Institución organizadora:
IBRO/LARC
Resumen:
<!--
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-parent:"";
margin:0cm;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
font-size:12.0pt;
font-family:"Times New Roman";
mso-fareast-font-family:"Times New Roman";
mso-ansi-language:EN-US;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;
text-underline:single;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;
text-underline:single;}
span.HTMLTypewriter3
{mso-style-name:"HTML Typewriter3";
mso-ansi-font-size:10.0pt;
mso-bidi-font-size:10.0pt;
font-family:"Courier New";
mso-ascii-font-family:"Courier New";
mso-fareast-font-family:"Times New Roman";
mso-hansi-font-family:"Courier New";
mso-bidi-font-family:"Courier New";}
p.HTMLPreformatted, li.HTMLPreformatted, div.HTMLPreformatted
{mso-style-name:"HTML Preformatted";
margin:0cm;
margin-bottom:.0001pt;
mso-pagination:widow-orphan;
tab-stops:45.8pt 91.6pt 137.4pt 183.2pt 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt 641.2pt 687.0pt 732.8pt;
font-size:12.0pt;
font-family:"Courier New";
mso-fareast-font-family:"Times New Roman";
mso-ansi-language:EN-US;
mso-fareast-language:EN-US;}
@page Section1
{size:612.0pt 792.0pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;
mso-header-margin:36.0pt;
mso-footer-margin:36.0pt;
mso-paper-source:0;}
div.Section1
{page:Section1;}
-->
HIPPOCAMPAL NMDA RECEPTORS ARE DIFFERENTIALLY INVOLVED IN
MEMORY CONSOLIDATION DEPENDING ON THEIR NR2 COMPOSITION.
Colettis N1;2;Cheli V1; Snitcofsky M1; Blanco C1,2;Quillfedt J3;Kornisiuk E1;Jerusalinsky
D1
1.IBC&N "Prof E De Robertis" Fac Med
& 2.Dept Anat, FacCs Vet, UBA. Buenos Aires, Argentina. 3. Dept Biophys, UFRGS,
POA, Brazil.
FONCyT
(PICT 05-14346), Univ. of Bs. As. (M040), CONICET (PIP 6086), CNRS/CONICET.
e-mail: tatanatatu@yahoo.com.ar
The hippocampus is involved in consolidation of various
different long term memories (LTM). The N-Methyl-D-Aspartate receptor (NMDAR)
is involved in activity-dependent synaptic plasticity and in related central
functions like learning and LTM. It always consists of the essential NR1 and
different NR2 (A-D), and sometimes NR3 subunits. NR2B has been postulated as
responsible of facilitating learning and memory, and LTP. To further analyze
its role in memory, adult Wistar rats were stereotaxically cannulated in both
hippocampus under anesthesia. Either the NMDAR non-selective antagonist MK801
or a NR2B subunit relatively selective antagonist ifenprodil (NR2C also), were
infused through the cannulae immediately after training in various behavioral
tasks. The rats were tested for retention 24 h later (LTM). We have shown that
hippocampal NMDARs are involved in habituation to an open field and in an
step-down inhibitory avoidance to a foot-shock. Ifenprodil infused into the
hippocampus had no evident effect on any of those tasks. However, when an
underthreshold foot-shock was applied, ifenprodil improved performance, while
control animals did not appear to remember the task. Neither MK801 nor
ifenprodil affected the performance in an object recognition task, suggesting
that early steps of consolidation of this task are independent of NMDAR in the
dorsal hippocampus. However, ifenprodil also exerted facilitatory effects in an
object location task. Hence, our results suggest that hippocampal NR2B
containing NMDA receptors would act as negative modulators on the early
consolidation of specific memories, with strong aversive and/or spatial content
rather than those mainly concerning novelty.