Rac1 and Nectin3 are essential for planar cell polarity-directed axon guidance in the peripheral auditory system.

Spiral ganglion neurons (SGNs) carry sound information from the cochlea to the hindbrain, and innervate either inner or outer hair cells. Type II SGNs (SGNIIs) extend peripheral afferents towards outer hair cells, which make a characteristic 90° turn towards the cochlear base and innervate multiple outer hair cells. It has been shown that the planar cell polarity (PCP) pathway acts non-autonomously in the cochlear epithelium to guide SGNII peripheral afferent turning.

Rac1 and Nectin3 are essential for PCP-directed axon guidance in the peripheral auditory system.

Our sense of hearing is critically dependent on the spiral ganglion neurons (SGNs) that connect the sound receptors in the organ of Corti (OC) to the cochlear nuclei of the hindbrain. Type I SGNs innervate inner hair cells (IHCs) to transmit sound signals, while type II SGNs (SGNIIs) innervate outer hair cells (OHCs) to detect moderate-to-intense sound. During development, SGNII afferents make a characteristic 90-degree turn toward the base of the cochlea and innervate multiple OHCs.

Non-Canonical Wnt Signaling Regulates Cochlear Outgrowth and Planar Cell Polarity via Gsk3β Inhibition.

During development, sensory hair cells (HCs) in the cochlea assemble a stereociliary hair bundle on their apical surface with planar polarized structure and orientation. We have recently identified a non-canonical, Wnt/G-protein/PI3K signaling pathway that promotes cochlear outgrowth and coordinates planar polarization of the HC apical cytoskeleton and alignment of HC orientation across the cochlear epithelium. Here, we determined the involvement of the kinase Gsk3β and the small GTPase Rac1 in non-canonical Wnt signaling and its regulation of the planar cell polarity (PCP) pathway in the cochlea.

The Property-Based Practical Applications and Solutions of Genetically Encoded Acetylcholine and Monoamine Sensors.

Neuromodulatory communication among various neurons and non-neuronal cells mediates myriad physiological and pathologic processes, yet defining regulatory and functional features of neuromodulatory transmission remains challenging because of limitations of available monitoring tools. Recently developed genetically encoded neuromodulatory transmitter sensors, when combined with superresolution and/or deconvolution microscopy, allow the first visualization of neuromodulatory transmission with nanoscale or microscale spatiotemporal resolution. and experiments have validated several high-performing sensors to have the qualities necessary for demarcating fundamental synaptic properties of neuromodulatory transmission, and initial analysis has unveiled unexpected fine control and precision of neuromodulation.