Neurobiology Student Seminar

Talk 1: Transduction of repetitive mechanical stimuli by Piezo1 & Piezo2 ion channels:
Several cell types experience repetitive mechanical stimuli, including vein endothelial cells during pulsating blood flow, inner ear hair cells upon sound exposure, and skin cells and their innervating DRG neurons when sweeping across a textured surface or touching a vibrating object. While mechanosensitive Piezo ion channels have been clearly implicated in sensing static touch, their roles in transducing repetitive mechanical stimuli are less clear. Here, we perform electrophysiological recordings of heterologously expressed mouse Piezo1 and mouse Piezo2 and find that both channels function as pronounced frequency filters whose transduction efficiencies vary with stimulus frequency, waveform, and duration. We then use numerical simulations and human disease-related point mutations to demonstrate that channel inactivation is the molecular mechanism underlying Piezo frequency filtering, and further show that frequency filtering is conserved in rapidly-adapting mouse DRG neurons. Our results give insight into the potential contributions of Piezos in transducing repetitive mechanical stimuli.

Talk 2: TrkB inhibition can reverse recent LTP through Rac1 modulation in spines of CA1 pyramidal neurons