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bioRxiv · 10.1101/2020.02.27.968065

Sensory input drives rapid homeostatic scaling of the axon initial segment in mouse barrel cortex

Jamann, N.·Dannehl, D.·Wagener, R.·Corcelli, C.·Schultz, C.·Staiger, J.·Kole, M. H. P.·Engelhardt, M.
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Abstract

The axon initial segment (AIS) is an important axonal microdomain for action potential initiation and implicated in the regulation of neuronal excitability during activity-dependent cortical plasticity. While structural AIS plasticity has been suggested to fine-tune neuronal activity when network states change, whether it acts as a homeostatic regulatory mechanism in behaviorally relevant contexts remains poorly understood. Using an in vivo model of the mouse whisker-to-barrel pathway in combination with immunofluorescence, confocal analysis and patch-clamp electrophysiological recordings, we observed bidirectional AIS plasticity. Furthermore, we find that structural and functional AIS remodeling occurs in distinct temporal domains: long-term sensory deprivation elicits an AIS length increase, accompanied with an increase in neuronal excitability, while sensory enrichment results in a rapid AIS shortening, accompanied by a decrease in action potential generation. Our findings highlight a central role of the AIS in the homeostatic regulation of neuronal input-output relations.

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Jamann, N., Dannehl, D., Wagener, R., Corcelli, C., Schultz, C., Staiger, J., Kole, M. H. P., Engelhardt, M.. 2020-02-28. Sensory input drives rapid homeostatic scaling of the axon initial segment in mouse barrel cortex. https://doi.org/10.1101/2020.02.27.968065

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