IBCN   20355
INSTITUTO DE BIOLOGIA CELULAR Y NEUROCIENCIA "PROFESOR EDUARDO DE ROBERTIS"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
NR2A-containing NMDA receptor expression rapidly increases after LTP induction in adult rats.
Autor/es:
A I AGUIRRE; M V BAEZ; M V OBERHOLZER; M CERCATO; D A JERUSALINSKY
Lugar:
Florencia
Reunión:
Congreso; IBRO Congress; 2011
Institución organizadora:
IBRO
Resumen:
IBRO 2011 NR2A-containing NMDA receptor expression rapidly increases after LTP induction in adult rats. Aguirre AI, Baez MV, Oberholzer MV, Cercato M,  Jerusalinsky D. NMDA receptors (NMDAR) are tetramers containing two NR1 subunits and two NR2 (or sometimes NR3) subunits. Depending on the NR2 composition, NMDAR changes its characteristics. In the hippocampus, NMDAr NR2 major subunits are NR2A and NR2B. Expression of NR2 subunits at hippocampus is widely studied during development.  At early stages of postnatal development NR2B expression is more abundant than NR2A but, at mature synapses, NR2A-containing NMDAR are predominant. There is also a change in synaptic expression after LTP induction. NR2B- containing NMDAR decreased at the time that NR2A-containing NMDAR increased at synapses, which was evaluated by electrophysiology assays. This switch was explained by a rapid increase in NR2B endocytosis followed by a delivery of NR2A-NMDA receptors to the synaptic membrane. However little is known about what happened with the expression (transcription-translation) of the NR2 subunits after LTP induction. For this reason To evaluate NR2A and NR2B subunits expresion after LTP, field potential recordings from hippocampal acute slices of young adult rats (P42-60) were analyzed. Stimulation was done at 0.033Hz for the same period in all slices. When indicated,  LTP was induced by a theta burst stimulation (TBS) protocol.  After electrophysiology assays, the expression of NMDA receptor subunits NR1, NR2A and NR2B was analyzed by western blot. At 30 minutes after LTP induction, preliminary results showed a slight increase in the expression of NMDA receptor subunits NR1 and NR2B. However,  at 70 minutes  post-LTP induction,  differences in NR1 and NR2A expression between LTP-induced and controls slices were significant (about 6 fold and 5 fold, respectively). In order to elucidate if these increased subunits are effectively incorporated into the membranes and reflected in a synaptic change, further assays are being carried out.