Several new members of the nerve growth factor family of neurotrophins, which comprises nerve growth factor itself, brain-derived neurotrophic factor and neurotrophins-3, -4 (also known as neurotrophin-5) and -6, have been isolated in recent years. Their signaling receptors have been identified as the Trk family of tyrosine protein kinases, thus facilitating the dissection of the signaling path...

To investigate the possibility of neurotrophins acting directly on hippocampal neurons, we first examined expression of the trk receptors in sections of adult rat brain and in cultures of embryonic rat hippocampus, and then investigated general and specific responses of cultured hippocampal neurons to each of the neurotrophins. In situ hybridization studies indicated high levels of expression o...

Neurotrophin expression in early stages of development is crucial for brain assembly and function. In particular, postnatal expression of neurotrophins has not been well documented in the neostriatum and in general neurotrophins or their receptor mRNA's are normally reported, but not protein expression. In the present study, immunocytochemical expression of BDNF, NT-3 and NT-4/5 was characteriz...

The cellular localization of mRNA for neurotrophin-4 (NT-4), a novel neurotrophic factor, in the developing whisker follicles and skin of the embryonic rat is demonstrated by in situ hybridization. Levels of NT-4 mRNA in the whisker pad decrease between embryonic day 13 (E13) and E20, correlating in time with the onset of naturally occurring neuronal death in the innervating trigeminal ganglion...

To explore the mechanism of diabetic erectile dysfunction, we studied the distribution of neurotrophins in the penises of diabetic rats, including nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4 (NT-4). Male Sprague-Dawley rats were injected with 65 mg/kg streptozotocin to induce diabetes mellitus (DM). The control rats were raised ...

The developing cerebellum expresses genes which encode for both neurotrophins and their receptors. The present study was designed to determine at what stages during cerebellar granule cell neurogenesis neurotrophin family molecules may act. We report here that in purified, well-characterized granule cell cultures (Gao et al., 1991; 1992), none of the neurotrophins stimulated proliferation of gr...

To understand the role of neurotrophins in the visual system, we investigated the distribution of both neurotrophins and their receptors within the retina of a fish that has the capacity to spontaneously regenerate its optic nerve axons after lesion. Intact retinas and retinas from tench, whose optic nerve had been crushed, were analyzed by immunohistochemistry and in situ hybridization. Trk re...

Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) are three representative neurotrophins responsible for the differentiation and survival of neurons, and their high-affinity receptors are tropomyosin-receptor-kinase (TRK)A, TRKB, and TRKC, respectively. In this study, we investigated the expression of neurotrophins in a mouse periodontal ligament cel...

The nerve growth factor (NGF) family comprises NGF, brain-derived neurotrophic factor (BDNF) and neurotrophins (NTs)-3, -4/5, -6 and -7, all of which are collectively referred to as neurotrophins. However, the expression of neurotrophins other than NGF in the salivary gland has not been described in detail. Through interaction with the TrkB receptor, BDNF plays an important role in long-term po...

Brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) are two neurotrophins that play distinct roles in geniculate (taste) neuron survival, target innervation, and taste bud formation. These two neurotrophins both activate the tropomyosin-related kinase B (TrkB) receptor and the pan-neurotrophin receptor p75. Although the roles of these neurotrophins have been well studied, the deg...