Background: The spatial gap between cochlear implants (CIs) and the auditory nerve limits frequency selectivity as large populations of spiral ganglion neurons (SGNs) are electrically stimulated synchronously. To improve CI performance, a possible strategy is to promote neurite outgrowth toward the CI, thereby allowing a discrete stimulation of small SGN subpopulations. Brain-derived neurotrophic factor (BDNF) is effective to stimulate neurite outgrowth from SGNs.
Method: TrkB (tropomyosin receptor kinase B) agonists, BDNF, and five known small-molecule BDNF mimetics were tested for their efficacy in stimulating neurite outgrowth in postnatal SGN explants. To modulate Trk receptor-mediated effects, TrkB and TrkC ligands were scavenged by an excess of recombinant receptor proteins. The pan-Trk inhibitor K252a was used to block Trk receptor actions.
Results: THF (7,8,3'-trihydroxyflavone) partly reproduced the BDNF effect in postnatal day 7 (P7) mouse cochlear spiral ganglion explants (SGEs), but failed to show effectiveness in P4 SGEs. During the same postnatal period, spontaneous and BDNF-stimulated neurite outgrowth increased. The increased neurite outgrowth in P7 SGEs was not caused by the TrkB/TrkC ligands, BDNF and neurotrophin-3 (NT-3).
Conclusions: The age-dependency of induction of neurite outgrowth in SGEs was very likely dependent on presently unidentified factors and/or molecular mechanisms which may also be decisive for the age-dependent efficacy of the small-molecule TrkB receptor agonist THF.
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http://dx.doi.org/10.3390/brainsci10090580 | DOI Listing |
Genes Cells
January 2025
Department of Genetic Biochemistry, The National Institutes of Biomedical Innovation, Health and Nutrition, Shinjuku-ku, Tokyo, Japan.
Catalytic subunit of DNA polymerase ζ (REV3), involved in translesion-replication is evolutionarily conserved from yeast and plants to higher eukaryotes. However, a large intermediate domain is inserted in REV3 of humans and mice. The domain has "DUF4683" region, which is significantly similar to human neurite extension and migration factor (NEXMIF).
View Article and Find Full Text PDFSci Rep
January 2025
Centro de Investigación en Medicina Traslacional "Severo R. Amuchástegui" (CIMETSA), Instituto Universitario de Ciencias Biomédicas de Córdoba (IUCBC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Naciones Unidas 420, Barrio Parque Vélez Sarsfield, X5016KEJ, Córdoba, Argentina.
Extracellular vesicles (EVs) play a critical role in the development of neural cells in the central nervous system (CNS). Human neural rosettes (hNRs) are radial cell structures that assemble from induced pluripotent stem cells (hiPSCs) and recapitulate some stages of neural tube morphogenesis. Here we show that hiPSCs and hNRs secrete EVs (hiPSC-EVs and hNR-EVs) with distinctive protein cargoes.
View Article and Find Full Text PDFBiomed Pharmacother
January 2025
College of Veterinary Medicine, Konkuk University, 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address:
Rett syndrome (RTT) is a neurological disorder caused by a mutation in the X-linked methyl-CpG binding protein 2 (MECP2), leading to cognitive and motor skill regression. Therapeutic strategies aimed at increasing brain-derived neurotrophic factor (BDNF) levels have been reported; however, BDNF treatment has limitations, including the inability to penetrate the blood-brain barrier, a short half-life, and potential for adverse effects when administered via intrathecal injection, necessitating novel therapeutic approaches. In this study, we focused on the adenosine A receptor (AR), which modulates BDNF and its downstream pathways, and investigated the therapeutic potential of CGS21680, an AR agonist, through in vitro and in vivo studies using R106W RTT model.
View Article and Find Full Text PDFCell Rep
January 2025
Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, South Korea; Neuroscience Research Institute, Medical Research Center, Seoul National University, Seoul 03080, South Korea; Transplantation Research Institute, Medical Research Center, Seoul National University, Seoul 03080, South Korea. Electronic address:
Cd99 molecule-like 2 (Cd99l2) is a type I transmembrane protein that plays a role in the transmigration of leukocytes across vascular endothelial cells. Despite its high expression in the brain, the role of Cd99l2 remains elusive. We find that Cd99l2 is expressed primarily in neurons and positively regulates neurite outgrowth and the development of excitatory synapses.
View Article and Find Full Text PDFBiomed Pharmacother
January 2025
Department of Anatomy, Chonnam National University Medical School, Hwasun 58128, Republic of Korea; Biomedical Science Graduate Program (BMSGP), Chonnam National University, Hwasun 58128, Republic of Korea. Electronic address:
Obesity is a prevalent metabolic disorder linked to insulin resistance, hyperglycemia, increased adiposity, chronic inflammation, and cognitive dysfunction. Recent research has focused on developing therapeutic strategies to mitigate cognitive impairment associated with obesity. Insulin growth factor-1 (IGF1) deficiency is linked to insulin resistance, glucose intolerance, and the progression of obesity-related central nervous system (CNS) disorders.
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