Behavioral and Systems Neuroscience Section, Department of Psychology, Rutgers, The State University of New Jersey, USA.
Chem Senses. 2013 Jan;38(1):77-89. doi: 10.1093/chemse/bjs081. Epub 2012 Nov 2.
Olfactory sensory deprivation during development has been shown to induce significant alterations in the neurophysiology of olfactory receptor neurons (ORNs), the primary sensory inputs to the brain's olfactory bulb. Deprivation has also been shown to alter the neurochemistry of the adult olfactory system, but the physiological consequences of these changes are poorly understood. Here we used in vivo synaptopHluorin (spH) imaging to visualize odorant-evoked neurotransmitter release from ORNs in adult transgenic mice that underwent 4 weeks of unilateral olfactory deprivation. Deprivation reduced odorant-evoked spH signals compared with sham-occluded mice. Unexpectedly, this reduction was equivalent between ORNs on the open and plugged sides. Changes in odorant selectivity of glomerular subpopulations of ORNs were also observed, but only in ORNs on the open side of deprived mice. These results suggest that naris occlusion in adult mice produces substantial changes in primary olfactory processing which may reflect not only the decrease in olfactory stimulation on the occluded side but also the alteration of response properties on the intact side. We also observed a modest effect of true sham occlusions that included noseplug insertion and removal, suggesting that conventional noseplug techniques may have physiological effects independent of deprivation per se and thus require more careful controls than has been previously appreciated.
在发育过程中嗅觉感觉剥夺已被证明会导致嗅球中嗅觉受体神经元（ORNs）的神经生理学发生重大变化，ORNs 是大脑嗅觉的主要感觉输入。剥夺也已被证明会改变成年嗅觉系统的神经化学，但这些变化的生理后果知之甚少。在这里，我们使用体内突触荧光素（spH）成像来可视化经历了 4 周单侧嗅觉剥夺的成年转基因小鼠中 ORNs 对气味刺激诱发的神经递质释放。与假闭塞小鼠相比，剥夺减少了气味刺激引发的 spH 信号。出乎意料的是，这种减少在开放和堵塞侧的 ORNs 之间是相等的。还观察到 ORNs 中嗅球亚群的气味选择性变化，但仅在剥夺小鼠的开放侧的 ORNs 中观察到。这些结果表明，成年小鼠的鼻腔阻塞会导致初级嗅觉处理发生重大变化，这不仅反映了闭塞侧嗅觉刺激的减少，还反映了完整侧反应特性的改变。我们还观察到真正的假闭塞（包括鼻塞插入和移除）的适度影响，这表明传统的鼻塞技术可能具有独立于剥夺本身的生理效应，因此需要比以前认识到的更仔细的控制。
