Small molecule Photoregulin3 prevents retinal degeneration in the mouse model of retinitis pigmentosa.

Regulation of rod gene expression has emerged as a potential therapeutic strategy to treat retinal degenerative diseases like retinitis pigmentosa (RP). We previously reported on a small molecule modulator of the rod transcription factor Nr2e3, Photoregulin1 (PR1), that regulates the expression of photoreceptor-specific genes. Although PR1 slows the progression of retinal degeneration in models of RP in vitro, in vivo analyses were not possible with PR1.

Potential of Small Molecule-Mediated Reprogramming of Rod Photoreceptors to Treat Retinitis Pigmentosa.

Purpose: Mutations in rod photoreceptor genes can cause retinitis pigmentosa (RP). Rod gene expression is regulated by the nuclear hormone receptor, Nr2e3. Genetic deletion of Nr2e3 reprograms rods into cells that resemble cone photoreceptors, and might therefore prevent their death from some forms of RP.

EphB2 signaling regulates lesion-induced axon sprouting but not critical period length in the postnatal auditory brainstem.

Background: Studies of developmental plasticity may provide insight into plasticity during adulthood, when neural circuitry is less responsive to losses or changes in input. In the mammalian auditory brainstem, globular bushy cell axons of the ventral cochlear nucleus (VCN) innervate the contralateral medial nucleus of the trapezoid body (MNTB) principal neurons. VCN axonal terminations in MNTB, known as calyces of Held, are very large and specialized for high-fidelity transmission of auditory information.

Profiling neurotransmitter receptor expression in the Ambystoma mexicanum brain.

Ability to regenerate limbs and central nervous system (CNS) is unique to few vertebrates, most notably the axolotl (Ambystoma sp.). However, despite the fact the neurotransmitter receptors are involved in axonal regeneration, little is known regarding its expression profile.

EphB signaling regulates target innervation in the developing and deafferented auditory brainstem.

Precision in auditory brainstem connectivity underlies sound localization. Cochlear activity is transmitted to the ventral cochlear nucleus (VCN) in the mammalian brainstem via the auditory nerve. VCN globular bushy cells project to the contralateral medial nucleus of the trapezoid body (MNTB), where specialized axons terminals, the calyces of Held, encapsulate MNTB principal neurons.

Formation and maturation of the calyx of Held.

Sound localization requires precise and specialized neural circuitry. A prominent and well-studied specialization is found in the mammalian auditory brainstem. Globular bushy cells of the ventral cochlear nucleus (VCN) project contralaterally to neurons of the medial nucleus of the trapezoid body (MNTB), where their large axons terminate on cell bodies of MNTB principal neurons, forming the calyces of Held.

Ephrin-B reverse signaling is required for formation of strictly contralateral auditory brainstem pathways.

Specificity in the projections from the mammalian ventral cochlear nucleus (VCN) is essential for sound localization. Globular bushy cells project from the VCN to the medial nucleus of the trapezoid body (MNTB) on the contralateral, but not the ipsilateral, side of the brainstem, terminating in large synaptic endings known as calyces of Held. The precision in this pathway is critical for the computation of interaural intensity differences, which are used in sound localization.

Auditory brainstem neural activation patterns are altered in EphA4- and ephrin-B2-deficient mice.

Auditory processing requires proper formation of tonotopically ordered projections. We have evaluated the role of an Eph receptor tyrosine kinase and an ephrin ligand in the development of these frequency maps. We demonstrated expression of EphA4 and ephrin-B2 in auditory nuclei and found expression gradients along the frequency axis in neonates.

Mitogen-associated protein kinase- and protein kinase A-dependent regulation of rhodopsin promoter expression in zebrafish rod photoreceptor cells.

Mitogen-associated protein kinase (MAPK)- and protein kinase A (PKA)-dependent signal transductions play important roles in the regulation of gene expression. Both MAPK and PKA pathways can be activated by light exposure. In this study, we investigated the effect of light on MAPK and PKA signal transduction and their roles in the regulation of rhodopsin promoter expression by using transgenic zebrafish [Tg(rhod::GFP)].