Effects of olfactory deprivation on action potential and ankyrin-G expression in glutamatergic neurons in the barrel cortex of mice

Abstract

To investigate effect of upregulated touch sensation induced by olfactory deprivation on action potentials and ankyrin-G expression in the glutamatergic neurons in the barrel cortex of mice. Chloroform (40 μL) was dropped into the unilateral nasal cavity to induce olfactory deprivation in 40 C57 mice (12 days old), whose glutamatergic neurons were genetically labeled with yellow fluorescent protein (YFP). Behavioral experiments were carried out to assess the effects of olfactory deprivation on whisker tactile of the mice. The action potentials of the glutamatergic neurons in the barrel cortex on the side with or without chloroform treatment (olfactory deprivation group and control group, respectively) were recorded by patch-clamp electrophysiological recording, and ankyrin-G expression in the proximal axonal segment of the neurons was detected with immunohistochemistry. Compared with those on the control side, the inter-spike intervals of the barrel glutamatergic neurons were significantly decreased and the absolute refractory periods were significantly shortened on the side with olfactory deprivation (P < 0.01); the expression of ankyrin-G was also significantly increased in the proximal axonal segment of the glutamatergic neurons in the barrel cortex on the side with olfactory deprivation (P < 0.01). Olfaction deprivation induces up-regulation of touch sensation in mice possibly as a result of functional enhancement of the glutamatergic neurons and increased ankyrin-G expression in the barrel cortex.