Increased expression of the NR2A NMDA receptor subunit in the prefrontal cortex of rats reared in isolation.
A hypofunction of the N-methyl-D-aspartate (NMDA) receptor has been implicated in the pathophysiology of schizophrenia. Compelling evidence of altered NMDA receptor subunit expression in the schizophrenic brain has not, however, so far emerged. Rats reared in isolation exhibit several characteristics, including disturbed sensory gating, which resemble those seen in schizophrenia. To explore the possibility that NMDA receptor dysfunction may contribute to the behavioral and neurochemical consequences of rearing rats in isolation, we compared NMDA receptor subunit expression in brains of rats which were housed in isolation and which displayed a deficit in prepulse inhibition of the acoustic startle response with that of socially housed controls. An initial microarray analysis revealed a 1.26-fold increase in NR2A transcript in the prefrontal cortex, but not in the nucleus accumbens, of rats reared in isolation compared with those housed socially. In contrast, NR1, NR2B, NR2C, NR2D, NR3A, and NR3B subunit expression was unchanged in either brain area. In a second cohort of animals, in situ hybridization revealed increased NR2A mRNA expression in the medial prefrontal cortex, an observation that was substantiated by increased [(3)H]CGP39653 binding suggesting that NR2A receptor subunit protein expression was also elevated in the medial prefrontal cortex of the same animals. No changes in expression of NR1 or NR2B subunits were observed at both mRNA and protein level. Altered NR2A subunit expression in the medial prefrontal cortex of rats reared in isolation suggests that NMDA receptor dysfunction may contribute to the underlying pathophysiology of this preclinical model of aspects of schizophrenia.
Turnock-Jones
Julia J
JJ
Department of Neurobiology, Babraham Institute, Babraham, CB2 4AT, United Kingdom. julia.jones@cancer.org.uk
Jennings
Carol A
CA
Robbins
Melanie J
MJ
Cluderay
Jane E
JE
Cilia
Jackie
J
Reid
Juliet L
JL
Taylor
Adam
A
Jones
Declan N C
DN
Emson
Piers C
PC
Southam
Eric
E
D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives / Q000378:metabolism; D000161:Acoustic Stimulation / Q000009:adverse effects; D000818:Animals; D000831:Animals, Newborn; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D007211:Indoles / Q000378:metabolism; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D017397:Prefrontal Cortex / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*; D013216:Reflex, Startle / Q000502:physiology; D012934:Social Isolation; D014316:Tritium / Q000378:metabolism
D007211:Indoles; C101788:MDL 105519; C120997:NR2A NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D014316:Tritium; C069052:CGP 39653; D015763:2-Amino-5-phosphonovalerate