Department of Neuroscience, University of Wisconsin Medical School, Madison, WI 53706.
Department of Biological Sciences, Marquette University, Milwaukee, WI 53233.
Proc Natl Acad Sci U S A. 2022 Mar 22;119(12):e2122501119. doi: 10.1073/pnas.2122501119. Epub 2022 Mar 15.
SignificanceGeckos are lizards capable of vocalization and can detect frequencies up to 5 kHz, but the mechanism of frequency discrimination is incompletely understood. The gecko's auditory papilla has a unique arrangement over the high-frequency zone, with rows of mechanically sensitive hair bundles covered with gelatinous sallets. Lower-frequency hair cells are tuned by an electrical resonance employing Ca-activated K channels, but hair cells tuned above 1 kHz probably rely on a mechanical resonance of the sallets. The resonance may be boosted by an electromotile force from hair bundles found to be evoked by changes in hair cell membrane potential. This unusual mechanism operates independently of mechanotransduction and differs from mammals which amplify the mechanical input using the motor protein prestin.
意义 壁虎是能够发声的蜥蜴，能够探测到高达 5 kHz 的频率，但频率辨别机制尚不完全清楚。壁虎的听觉乳头在高频区有独特的排列方式，一排排机械敏感的毛束覆盖着凝胶状的鳞片。低频毛细胞通过一种利用 Ca 激活的 K 通道的电共振进行调谐，而调谐频率高于 1 kHz 的毛细胞可能依赖于鳞片的机械共振。这种共振可能会受到毛束的电动力的增强，而这种电动力是由毛细胞膜电位的变化引起的。这种不寻常的机制独立于机械转导，与使用运动蛋白 prestin 放大机械输入的哺乳动物不同。
