Volume 38, Issue 3, 2022


In our cochleae, the inner hair cell (IHC) is responsible for converting sound-induced vibrations into auditory signals via 20–30 ribbon synapses with heterogeneous properties at the basolateral pole. Liu et al. reconstructed mouse IHCs in 3D using state-of-the-art volume electron microscopy and artifi cial intelligence-assisted segmentation methods. They uncovered two IHC subtypes based on distinct cell body morphology and the spatial gradient of synaptic ribbons. One tall and slim, the other short and stout, just like the two well-known cartoon characters (from early productions of Shanghai Animation Film Studio in the 1960s) on the cover image, they have different “personalities” and “dream occupations”. The fine structural tuning and putative functional diversity of these two IHC subtypes, which are arranged in a staggered manner in the most sensitive mid-cochlear region, may allow complementary coding of a wide range of sound intensities. See pages 235–248. (Cover art by Dr. Yunfeng Hua and Shanghai Animation Film Studio).