Research ReportSingle mechanically-gated cation channel currents can trigger action potentials in neocortical and hippocampal pyramidal neurons

- Neocortical and hippocampal pyramidal neurons express mechano-gated (MG) cation channels.
- Brief MG channel openings contribute to a resting conductance of pyramidal neurons.
- Single MG channels can trigger spiking in pyramidal cells.
- Mechanical forces that have a profound affect on brain function may activate MG channels.

The mammalian brain is a mechanosensitive organ that responds to different mechanical forces ranging from intrinsic forces implicated in brain morphogenesis to extrinsic forces that can cause concussion and traumatic brain injury. However, little is known of the mechanosensors that transduce these forces. In this study we use cell-attached patch recording to measure single mechanically-gated (MG) channel currents and their affects on spike activity in identified neurons in neonatal mouse brain slices. We demonstrate that both neocortical and hippocampal pyramidal neurons express stretch-activated MG cation channels that are activated by suctions of ~25 mm Hg, have a single channel conductance for inward current of 50-70 pS and show weak selectivity for alkali metal cations (i.e., Na+