A critical role for Piezo2 channels in the mechanotransduction of mouse proprioceptive neurons

Proprioceptors are responsible for the conscious sensation of limb position and movement, muscle tension or force and balance. Recent evidence suggests that Piezo2 is a low threshold mechanosensory receptor in the peripheral nervous system, acting as a transducer for touch sensation and proprioception. Thus, we characterized proprioceptive neurons in the mesencephalic trigeminal nucleus that are involved in processing proprioceptive information from the face and oral cavity. This is a specific population of neurons that produce rapidly adapting mechanically-activated currents that are fully dependent on Piezo2. As such, we analyzed the deficits in balance and coordination caused by the selective deletion of the channel in proprioceptors (conditional knockout). The data clearly shows that Piezo2 fulfills a critical role in a defined homogeneous population of proprioceptor neurons that innervate the head muscles, demonstrating that this ion channel is essential for mammalian proprioceptive mechanotransduction.K.K.B. is supported by a postdoctoral fellowship from the medical faculty of the Heidelberg University. This work was supported by grants from the Spanish government SAF2013-45608-R (to A.G.) and a FPI fellowship to D. F.-P. The Instituto de Neurociencias is a “Centre of Excellence Severo Ochoa”.Peer reviewe

Perinatal correlated retinal activity is required for the wiring of visual axons in non-image forming nuclei

Resumen del trabajo presentado al 2nd Meeting on Spontaneous Activity in Brain Development (SPONT), celebrado en Altea, Alicante (españa) del 6 al 8 de junio de 2022.The formation of the visual system is a complex multistep process that includes the establishment of proper connectivity of retinal ganglion cell (RGC) axon terminals with their relay neurons located in the brain. In mammals, the assembly of the different components of the visual circuit occurs at perinatal stages before eye opening. Upon reaching the target nuclei RGC axons extensively arborize and subsequently refine to establish the final connections. Spontaneous activity generated in the immature retina plays an essential role in the refinement of visual terminals at the main image-forming nuclei (IFN) that follow an eye-specific and retinotopic organization. However, the molecular mechanisms underlying spontaneous activity-dependent axon remodeling, and the influence of this activity in the connectivity of non-image forming nuclei (NIFN) that lack precise retinotopic maps and/or eye-specific segregation, are not well known. Here, by generating conditional mice with disturbed spontaneous retinal activity and analyzing their retinal transcriptomic profiles, we identified novel players involved in axon refinement at the visual nuclei (e. g. Syt13). The analysis of visual projections in the NIFN of these mice revealed that correlated-retinal activity shapes final connectivity in non-retinotopic or eye-specific segregating visual nuclei.Peer reviewe

Role of Piezo2 channels in mechanical ocular pain

Resumen del trabajo presentado al International Workshop on Chronic Pain and Itch: Mechanisms and Circuits, celebrado en Alicante (España) del 20 al 22 de octubre de 2021.Ministerio de Ciencia e Innovación, SAF2016-77233-R and PID2019-108194RB-100 co-financed by the European Regional Development Fund (ERDF), and the “Severo Ochoa” Program for Centers of Excellence in R&D SEV-2013-0317 and SEV-2017-0723.Peer reviewe