Neurons are highly polarized cells exhibiting axonal and somatodendritic domains with distinct complements of cytoplasmic organelles. Although some organelles are widely distributed throughout the neuronal cytoplasm, others are segregated to either the axonal or somatodendritic domains. Recent findings show that organelle segregation is largely established at a pre-axonal exclusion zone (PAEZ) within the axon hillock. Polarized sorting of cytoplasmic organelles at the PAEZ is proposed to depend mainly on their selective association with different microtubule motors and, in turn, with distinct microtubule arrays. Somatodendritic organelles that escape sorting at the PAEZ can be subsequently retrieved at the axon initial segment (AIS) by a microtubule- and/or actin-based mechanism. Dynamic sorting along the PAEZ-AIS continuum can thus explain the polarized distribution of cytoplasmic organelles between the axonal and somatodendritic domains.
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http://dx.doi.org/10.3389/fncel.2016.00088 | DOI Listing |
Biochem Biophys Rep
December 2024
Laboratory of Biochemistry, School of Pharmacy, Nihon University, Narashinodai, Funabashi, Chiba, 274-8555, Japan.
Tau is typically an axonal protein, but in neurons of brains affected by Alzheimer's disease (AD), aggregation of hyperphosphorylated tau in the somatodendritic compartment causes neuronal death. We have previously demonstrated that tau mRNA is transported within dendrites and undergoes immediate translation and hyperphosphorylation of AD epitopes in response to NMDA receptor stimulation. Although this explains the emergence of hyperphosphorylated tau in dendrites, the relationship between tau hyperphosphorylation and aggregation is not well understood.
View Article and Find Full Text PDFMutations in the gene ( ) are among the most frequently occurring genetic forms of amyotrophic lateral sclerosis (ALS). Early pathogenesis of -ALS involves impaired DNA damage response and axonal degeneration. However, it is still poorly understood how these gene mutations lead to selective spinal motor neuron (MN) degeneration and how nuclear and axonal phenotypes are linked.
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October 2024
Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA. Electronic address:
Neuroscientist
August 2024
Department of Neural and Behavioral Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA, USA.
Complex mechanisms govern the transport and action of oxytocin (Oxt), a neuropeptide and hormone that mediates diverse physiologic processes. While Oxt exerts site-specific and rapid effects in the brain via axonal and somatodendritic release, volume transmission via CSF and the neurovascular interface can act as an additional mechanism to distribute Oxt signals across distant brain regions on a slower timescale. This review focuses on modes of Oxt transport and action in the CNS, with particular emphasis on the roles of perivascular spaces, the blood-brain barrier (BBB), and circumventricular organs in coordinating the triadic interaction among circulating blood, CSF, and parenchyma.
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July 2024
Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address:
To achieve the functional polarization that underlies brain computation, neurons sort protein material into distinct compartments. Ion channel composition, for example, differs between axons and dendrites, but the molecular determinants for their polarized trafficking remain obscure. Here, we identify mechanisms that target voltage-gated Ca channels (Cas) to distinct subcellular compartments.
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