Wilson D A
Department of Zoology, University of Oklahoma, Norman 73019, USA.
Brain Res. 1995 Apr 24;677(2):238-42. doi: 10.1016/0006-8993(95)00151-f.
Unilateral olfactory deprivation for the first 3 postnatal weeks results in an enhancement of granule cell mediated, feedback inhibition of mitral cells in the rat olfactory bulb. Granule cells are excited by mitral cells by both non-NMDA and NMDA receptors. The present report describes the effect of the NMDA antagonist MK-801 (0.75 mg/kg) on the expression of deprivation enhanced inhibition. The results demonstrate that (1) enhancement of lateral olfactory tract paired-pulse inhibition of evoked potentials in deprived bulbs was stimulus intensity dependent, with the greatest difference expressed at highest stimulus intensities; (2) MK-801 reduced inhibition in both undeprived and deprived bulbs in a stimulus intensity dependent manner, with the greatest reduction occurring at highest stimulus intensities; (3) MK-801 eliminated the stimulus intensity effect on inhibition in both groups; and (4) following MK-801, deprived bulbs showed the same or less inhibition than undeprived bulbs.
出生后前三周进行单侧嗅觉剥夺会增强大鼠嗅球中颗粒细胞介导的对二尖瓣细胞的反馈抑制。颗粒细胞通过非NMDA和NMDA受体被二尖瓣细胞兴奋。本报告描述了NMDA拮抗剂MK-801（0.75mg/kg）对剥夺增强抑制表达的影响。结果表明：（1）剥夺嗅球中嗅外侧束对诱发电位的配对脉冲抑制增强与刺激强度有关，在最高刺激强度时差异最大；（2）MK-801以刺激强度依赖的方式降低了未剥夺和剥夺嗅球中的抑制作用，在最高刺激强度时降低最大；（3）MK-801消除了两组中刺激强度对抑制的影响；（4）给予MK-801后，剥夺嗅球的抑制作用与未剥夺嗅球相同或更小。
