Homocysteine reduces NMDAR desensitization and differentially modulates peak amplitude of NMDAR currents, depending on GluN2 subunit composition.
J Neurophysiol
; 110(7): 1567-82, 2013 Oct.
Article
en En
| MEDLINE
| ID: mdl-23864370
ABSTRACT
N-methyl-d-aspartate receptors (NMDARs) have been linked to schizophrenia because agents that bind the receptor, like ketamine and phencyclidine, are capable of inducing schizophrenia-like symptoms. Here we show that the amino acid homocysteine (HCY), which is increased in the blood of schizophrenia patients, reduces desensitization of NMDARs in cultured mouse neurons, human embryonic kidney cells transfected with GluN1 + GluN2A, GluN2B, or GluN2D subunits, and hippocampal slices. HCY also alters the peak amplitude of NMDAR currents, depending on the GluN2 subunit the receptor contains; GluN1 + GluN2A-containing NMDARs show an increase in peak amplitude when exposed to HCY, while GluN1 + GluN2B-containing NMDARs show a decrease in peak amplitude. Both peak amplitude and desensitization effects of HCY can be occluded by saturating the NMDAR with glycine. Since glycine concentrations are not saturating in the brain, HCY could play an NMDAR-modulating role in the nervous system. We also show that HCY shares characteristics with glutamate and suggest that HCY affects both the agonist and co-agonist site of the NMDAR.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Potenciales de Acción
/
Receptores de N-Metil-D-Aspartato
/
Homocisteína
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Neurophysiol
Año:
2013
Tipo del documento:
Article