Philpot B D, Men D, McCarty R, Brunjes P C
Department of Psychology, University of Virginia, Charlottesville 22903, USA.
Neuroscience. 1998 Aug;85(3):969-77. doi: 10.1016/s0306-4522(97)00667-2.
Several lines of evidence strongly suggest that reduced olfactory nerve activity results in decreased bulb dopamine content. In the present study, high performance liquid chromatography with electrochemical detection was used to assess catecholamine levels in bulbs from postnatal day 60 rats that had undergone either unilateral naris cautery or a sham surgery on day 30. Thirty days of odor deprivation dramatically reduced dopamine and dihydroxyphenylacetic acid levels in functionally-deprived bulbs (ipsilateral to occluded nares) as compared to contralateral controls, while norepinephrine and dihydroxyphenylglycol levels were unchanged. The loss of dopamine was more severe in medial as compared to lateral aspects of experimental bulbs, while the loss of dihydroxyphenylacetic acid was similar on the two sides. To test directly the hypothesis that afferent activity regulates dopamine and dihydroxyphenylacetic acid content, 1 h of high frequency tetanic nerve stimulation was provided to the rostral-medial olfactory nerve layer in deprived olfactory bulbs, and catecholamine levels were assessed from 6 to 192 h later. Partial and temporary recovery of dopamine was observed in medial aspects of the bulb when rats were examined 96 h later, while consistent recovery of dihydroxyphenylacetic acid content was not apparent. These data corroborate evidence that olfactory nerve activity is a potent regulator of bulb dopamine and indicate that continued afferent input is necessary to maintain dopamine levels.
多项证据有力地表明，嗅觉神经活动的降低会导致嗅球多巴胺含量减少。在本研究中，采用高效液相色谱-电化学检测法评估出生后60天的大鼠在出生后第30天接受单侧鼻孔烧灼或假手术的嗅球中的儿茶酚胺水平。与对侧对照相比，30天的气味剥夺显著降低了功能剥夺嗅球（与阻塞鼻孔同侧）中的多巴胺和二羟基苯乙酸水平，而去甲肾上腺素和二羟基苯乙醇水平未发生变化。与实验嗅球的外侧相比，内侧的多巴胺损失更为严重，而两侧的二羟基苯乙酸损失相似。为了直接检验传入活动调节多巴胺和二羟基苯乙酸含量这一假设，对剥夺嗅觉的嗅球中的吻侧内侧嗅神经层进行了1小时的高频强直神经刺激，并在6至192小时后评估儿茶酚胺水平。96小时后检查大鼠时，在嗅球内侧观察到多巴胺有部分和暂时的恢复，而二羟基苯乙酸含量并未出现持续恢复。这些数据证实了嗅觉神经活动是嗅球多巴胺的有效调节因子这一证据，并表明持续的传入输入对于维持多巴胺水平是必要的。
