image: A recent work reveals the essential role of PV inhibitory neurons in the contribution to the tonotopic organization of the auditory cortex.
Credit: ©Science China Press
Xiaojing Tang et al. at Chongqing Institute for Brain and Intelligence recently published a study in Science Bulletin titled “Parvalbumin Interneurons Are Essential for Tonotopy Strength in the Auditory Cortex”. This work reveals the essential role of PV inhibitory neurons in the contribution to the tonotopic organization of the auditory cortex.
It is well known that the auditory system—from the cochlea to the cortex—encodes sound frequency through spatially ordered representations, forming a topographic map. Although excitatory neurons have been considered necessary for tonotopy in the cortex, the role of inhibitory interneurons remains unclear.
This team developed a 2-Channel Alternating exposure wide-Field Explorer (2-CAFE) that enables the measurement of sound responsiveness of distinct neuron types in awake mice. Combined with two-photon imaging, they observed that GABAergic interneurons followed a similar tonotopic organization to the conventional auditory maps at both mesoscale and single-cell resolutions. Among the major interneuron subtypes–parvalbumin (PV), somatostatin (SST), and vasoactive intestinal peptide (VIP)–PV interneurons demonstrated a critical role in maintaining tonotopy. Inactivation of PV neurons, but not VIP or SST neurons, significantly weakened the tonotopic strength in the auditory cortex. These findings suggest that PV interneurons are essential components of auditory cortical tonotopy.
This work provides a comprehensive characterization of spatial organization among inhibitory neuron subtypes in the auditory cortex and offers new insight into the spatial encoding mechanisms of sensory information in the cortex.
Professor Xiaowei Chen from Third Military Medical University, Dr. Zhikai Zhao from Chongqing University, and Professor Sunny C. Li from Chongqing Institute for Brain and Intelligence served as co-corresponding authors. Xiaojing Tang (Chongqing Institute for Brain and Intelligence), Zhikai Zhao (Chongqing University), and Longhui Li (Chongqing University) contributed as co-first authors. The study was supported by funding from the National Key R&D Program of China, the National Natural Science Foundation of China, and China Postdoctoral Science Foundation.
Journal
Science Bulletin