The chick embryo (Gallus domesticus) is one of the most important model systems in vertebrate developmental biology. The development and function of its auditory brainstem circuitry is exceptionally well studied. These circuits represent an excellent system for genetic manipulation to investigate mechanisms controlling neural circuit formation, synaptogenesis, neuronal polarity, and dendritic a...

Neuronal arborization is regulated by cell-autonomous and nonautonomous mechanisms including endosomal signaling via BDNF/TrkB. The endosomal Na⁺/H⁺ exchanger 6 (NHE6) is mutated in a new autism-related disorder. NHE6 functions to permit proton leak from endosomes, yet the mechanisms causing disease are unknown. We demonstrate that loss of NHE6 results in overacidification of the endosomal comp...

N-acetylserotonin (NAS), the immediate precursor of melatonin, the pineal gland indole, is regulated in a circadian rhythm. NAS swiftly activates TrkB in a circadian manner and exhibits antidepressant effect in a TrkB-dependent manner. Here we show that NAS regulates an early event of neurogenesis by increasing neuronal progenitor cell (NPC) proliferation. Subchronic and chronic NAS administrat...

Glycine transporters (GlyT), GlyT1 and GlyT2, are responsible for the termination of glycine-mediated synaptic activity through removal of neurotransmitter from synaptic cleft. Brain-derived neurotrophic factor (BDNF) activates its high affinity tropomyosin-related kinase (Trk) receptors, namely TrkB, which includes full length (TrkB-FL) and truncated (TrkB-T) isoforms. In this article we evalu...

Long-term potentiation (LTP) is a process that certain types of synaptic stimulation lead to a long-lasting enhancement in the strength of synaptic transmission. Studies in recent years indicate the importance of molecular pathways in the development of memory and learning. Tropomyosin receptor kinase B (TrkB) is a member of the neurotrophin receptor tyrosine kinase family, that its ligand is b...

The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropom...

Toward understanding topographically specific branching of retinal axons in their target area, we have studied the interaction between neurotrophin receptors and members of the Eph family. TrkB and its ligand BDNF are uniformly expressed in the retina and tectum, respectively, and exert a branch-promoting activity, whereas EphAs and ephrinAs are expressed in gradients in retina and tectum and c...

Brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, are broadly expressed in the developing and adult mammalian brain. BDNF/TrkB-stimulated intracellular signaling is critical for neuronal survival, morphogenesis, and plasticity. It is well known that binding of BDNF to TrkB elicits various intracellular signaling pathways, including mitogen-activated protein kinase/extracellular s...

BDNF (brain-derived neurotrophic factor) and its receptor TrkB (tropomyosin receptor kinase B) play important roles in the progression of cancer, including transitional cell carcinoma (TCC) cells reported in our previous investigation. In this study, we used a specific TrkB antibody (Ab) to evaluate its effects on survival, proliferation and migration/invasion in three TCC cell lines (BFTC905, ...

Learning-induced trophic activity is thought to be critical for maintaining health of the aging brain. We report here that learning, acting through an unexpected pathway, activates synaptic receptors for one of the brain's primary trophic factors. Unsupervised learning, but not exploratory activity alone, robustly increased the number of postsynaptic densities associated with activated (phospho...