Journal: Science Advances

Article Title: Lamellar Schwann cells in the Pacinian corpuscle potentiate vibration perception

doi: 10.1126/sciadv.adt5110

Figure Lengend Snippet: ( A ) Schematic of exposed optogenetic activation of PCs during afferent recording (left). PCs on mouse fibula (each bright green spot is one PC), identified by EYFP or GFP (green fluorescent protein) expression in the inner core structures (green), were exposed after pulling skin and muscle aside (right). ( B ) With blue laser power at 5 mW/mm 2 , the latency of light-driven spiking of the afferent is very consistent regardless of stimulus pulse duration. ( C ) Example of spiking from PCs stimulated by blue light versus a mechanical stimulus. ( D ) Intensity-dependent activation of five afferents. Left, first spike latencies for PC afferents from optogenetic activation of LSCs; right, instantaneous firing rate during optogenetic activation of LSCs. ( E ) Left, example recording of two afferents (top, ChR2 + ; bottom, ArchT + ) in response to 400-Hz hindlimb vibration, with light off (black) or on (blue/yellow). The timing of action potentials (blue/yellow dots) relative to periodic cycles of the 400-Hz vibration (red) shows the degree of entrainment. Right, with yellow light stimulation, the distribution of standardized inter-spike intervals of an example afferent at 400-Hz vibration shows decreasing degree of phase-locking probability. ( F ) Left, phase-locking probability of afferents affected by optogenetic activation or inactivation of PC-LSCs (paired-sample t test, * P < 0.0001). Right, spiking rate of afferents affected by optogenetic activation or inactivation of PC-LSCs (paired-sample t test, * P < 0.0001) in Etv1-ChR2 ( n = 4) and Etv1-ArchT mice ( n = 5). ( G ) Left, tuning curve shifting of two example afferents after inactivation of PC-LSCs by yellow light. Right, frequency tuning of afferents affected by optogenetic activation or inactivation of PC-LSCs (paired-sample t test, * P < 0.001). ( H ) Schematic model showing how PC-LSCs contribute to the coding of vibration. Additional spikes from PC-LSC activation (blue) illustrate enhanced excitability of the PC-LTMR.

Article Snippet: Experiments involving optogenetic manipulation of Schwann cells were conducted in double-transgenic mice generated by mating homozygous Ai32 mice carrying a floxed ChR2 -EYFP (enhanced yellow fluorescent protein) fusion gene inserted in the Gt(ROSA)26Sor locus in a C57BL/6 strain (Jackson Laboratory; stock no. 012569) or homozygous Ai40 mice carrying a floxed ArchT -EYFP fusion gene inserted in the Gt(ROSA)26Sor locus in a C57BL/6 strain (Jackson Laboratory; stock no. 021188) with heterozygote ER81/Etv1-CreER mice.

Techniques: Activation Assay, Expressing