Expression of NMDA receptor-1 induced by NMDA in the brain of neonatal SD rats

Abstract

Objective: To determine the regulation of the expression of NMDA receptor-1 induced by NMDA in the brain of neonatal SD rats. Methods: Neonatal SD rats (n = 90) were randomly divided into normal control (n = 6) and NMDA injected group (subdivided into 10 nmol-0 min, 15 min, 30 min, 1 h, 2 h, 4 h groups, and 10, 20, 50 nmol groups, each n = 6). NMDA fluorescent inmmunohistological staining and TTC (2,3,5-triphenyltetrazolium chloride) staining techniques were used. Results: At 30 min after the injection of 10 nmol NMDA, a few NR1 positive cells could be observed along the injection tract. At 1 h after the injection, NR1 positive cells in large quantity could be observed in the hippocampal CA1 region and paraventricular thalamus of the ipsilateral hemisphere. The number and location of positive cells at 2 h and 4 h after the injection were not much different from that at 1 h after the injection. At 2 h after injection, stronger NR1 expression was observed in the 50 nmol injection group. In addition, slight crinkle of the cell wall with mild condensation of the nuclei was also observed in the 50 nmol injection group. At 2 h after the injection, no abnormality was observed in 10, 20, or 50 nmol group after TTC staining. Conclusion: The NR1 induced by NMDA is expressed in a time-dependent and dose-dependent pattern after a short period of "delay", providing a possible "therapeutic window" for using NMDA receptor antagonist to treat diseases relating to the NMDA receptor activation.