MK-801 PREVENTS THE INCREASED NMDA-NR1 AND NR2B SUBUNITS MRNA EXPRESSION OBSERVED IN THE HIPPOCAMPUS OF RATS TOLERANT TO DIAZEPAM

ALMIRON RS; MARIELA F. PÉREZ.; OSCAR A RAMIREZ

BRAIN RESEARCH

ELSEVIER SCIENCE BV

Año: 2004 vol. 1008 p. 54 - 54

0006-8993

he chronic diazepam administration in rats has been show from our previous results, to produce an increased synaptic plasticity. Furthermore, this occurs with a concomitant over expression of the mRNA NR1 and NR2B N-methyl-D-aspartate receptor subunits. MK-801, a non-competitive antagonist of N-methyl-D-aspartate receptor, impairs both the development of conditioned tolerance to diazepam and the hippocampal long-term potentiation generation. In the present study, we have further investigated the hippocampal glutamatergic transmission in the development of tolerance to diazepam. Our results demonstrate that the development of tolerance to the hypolocomotive effect of diazepam, along with the increased hippocampal synaptic plasticity and the associated over expression of the mRNA NR1 and NR2B N-methyl-D-aspartate receptor subunits, were blocked by previous MK-801 administration. We suggest that the participation of hippocampal glutamatergic transmission is relevant to increased hippocam