Detection of near-atmospheric concentrations of CO2 by an olfactory subsystem in the mouse
Detection of near-atmospheric concentrations of CO2 by an olfactory subsystem in the mouse
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DOI：
10.1126/science.1144233
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发表时间：
2007-08-17
期刊：
影响因子：
56.9
通讯作者：
Luo, Minmin
中科院分区：
文献类型：
--
作者：
Hu, Ji;Zhong, Chun;Luo, Minmin
二氧化碳(CO2)对许多生物体来说是一种重要的环境线索，但对人类来说是无味的。目前尚不清楚哺乳动物的嗅觉系统能否探测到平均大气水平(0.038%)附近的二氧化碳浓度。我们证明了碳酸氢酶II(CAII)，一种分解二氧化碳的酶，在小鼠嗅觉神经元的一个亚群中表达，这些神经元表达鸟苷酸环化酶D(GC-D+神经元)，并将轴突投射到嗅球的项链小球。暴露在二氧化碳中激活了这些GC-D+神经元，而暴露在二氧化碳中的小鼠激活了与项链肾小球相关的球状神经元。行为测试显示二氧化碳检测阈值类似于0.066%，而这种敏感的二氧化碳检测需要CAII活动。我们的结论是，小鼠通过GC-D+神经元的嗅觉子系统检测到接近大气浓度的二氧化碳。
Carbon dioxide (CO2) is an important environmental cue for many organisms but is odorless to humans. It remains unclear whether the mammalian olfactory system can detect CO2 at concentrations around the average atmospheric level (0.038%). We demonstrated the expression of carbonic anhydrase type II (CAII), an enzyme that catabolizes CO2, in a subset of mouse olfactory neurons that express guanylyl cyclase D (GC-D+ neurons) and project axons to necklace glomeruli in the olfactory bulb. Exposure to CO2 activated these GC-D+ neurons, and exposure of a mouse to CO2 activated bulbar neurons associated with necklace glomeruli. Behavioral tests revealed CO2 detection thresholds of similar to 0.066%, and this sensitive CO2 detection required CAII activity. We conclude that mice detect CO2 at near-atmospheric concentrations through the olfactory subsystem of GC-D+ neurons.