N-methyl-D-aspartate receptor blockade during development induces short-term but not long-term changes in c-Jun and parvalbumin expression in the rat cervical spinal cord.
During postnatal development, N-methyl-D-aspartate receptor (NMDA-R) expression progressively decreases in ventral and deep dorsal horns. This transient expression might play a role in activity-dependent development of segmental circuitry. NMDA-Rs were blocked unilaterally in the lower cervical spinal cord using Elvax implants that released the NMDA-R antagonist MK-801 maximally over a 2-week period from postnatal day 7 (P7) onward. At P14, the ratio of c-Jun immunoreactive motoneurons ipsilateral/contralateral to the implants was significantly increased and the ratio of parvalbumin immunoreactive neurons decreased, compared to control implants. However, at P84, MK-801-treated and control spinal cords appeared the same. Therefore, NMDA-R blockade during development only transiently altered expression of activity-dependent proteins in the spinal cord, unlike lesions to the developing motor cortex, which we have previously shown to have a permanent effect.
Gibson
C L
CL
Developmental Neuroscience Group, Department of Child Health, University of Newcastle, Newcastle upon Tyne, United Kingdom.
Clowry
G J
GJ
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D016291:Dizocilpine Maleate / Q000008:administration & dosage / Q000494:pharmacology*; D004343:Drug Implants; D007839:Functional Laterality; D016758:Genes, jun; D009046:Motor Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010320:Parvalbumins / Q000032:analysis / Q000378:metabolism*; D011145:Polyvinyls; D016755:Proto-Oncogene Proteins c-jun / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D013116:Spinal Cord / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology
D004343:Drug Implants; D010320:Parvalbumins; D011145:Polyvinyls; D016755:Proto-Oncogene Proteins c-jun; D016194:Receptors, N-Methyl-D-Aspartate; C016438:ethylenevinylacetate copolymer; D016291:Dizocilpine Maleate