Truncated TrkB receptor-induced outgrowth of dendritic filopodia involves the p75 neurotrophin receptor.
The Trk family of receptor tyrosine kinases and the p75 receptor (p75NTR) mediate the effects of neurotrophins on neuronal survival, differentiation and synaptic plasticity. The neurotrophin BDNF and its cognate receptor tyrosine kinase, TrkB.FL, are highly expressed in neurons of the central nervous system. At later stages in postnatal development the truncated TrkB splice variants (TrkB.T1, TrkB.T2) become abundant. However, the signalling and function of these truncated receptors remained largely elusive.We show that overexpression of TrkB.T1 in hippocampal neurons induces the formation of dendritic filopodia, which are known precursors of synaptic spines. The induction of filopodia by T…
Huntingtin controls neurotrophic support and survival of neurons by enhancing BDNF vesicular transport along microtubules.
AbstractPolyglutamine expansion (polyQ) in the protein huntingtin is pathogenic and responsible for the neuronal toxicity associated with Huntington's disease (HD). Although wild-type huntingtin possesses antiapoptotic properties, the relationship between the neuroprotective functions of huntingtin and pathogenesis of HD remains unclear. Here, we show that huntingtin specifically enhances vesicular transport of brain-derived neurotrophic factor (BDNF) along microtubules. Huntingtin-mediated transport involves huntingtin-associated protein-1 (HAP1) and the p150Glued subunit of dynactin, an essential component of molecular motors. BDNF transport is attenuated both in the disease context and b…
The expression mechanism of the residual LTP in the CA1 region of BDNF k.o. mice is insensitive to NO synthase inhibition
Abstract BDNF and nitric oxide signaling both contribute to long-term potentiation (LTP) at glutamatergic synapses, but to date, few studies analyzed the interaction of both signaling cascades in the same synaptic pathway. Here we addressed the question whether the residual LTP in the CA1 region of hippocampal slices from heterozygous BDNF knockout mice (BDNF +/− ) is dependent on nitric oxide (NO) signaling. Extracellular recording of synaptic field potentials elicited by presynaptic Schaffer collateral stimulation was performed in the CA1 region of hippocampal slices of 4- to 6-week-old mice, and LTP was induced by a theta burst stimulation protocol. Application of the nitric oxide inhibi…