Stable microtubules provide nucleation seeds for microtubule assembly and protrusion, as well as tracks for the preferential binding of microtubule-based motors that transport membrane-bound organelles and regulatory macromolecular complexes during axon formation.ĭynamic microtubules in growth cones act as sensors of cellular conditions by extending in various directions in the peripheral actin-rich domain.
#Dendrite vs axon plus
Neuronal microtubules are regulated by many proteins, including assembly promoting factors, such as collapsin response mediator protein 2 (CRMP2) stabilizers, such as structural or classical microtubule-associated proteins (MAPs) destabilizing factors, such as stathmin microtubule severing proteins, such as katanin plus end tracking proteins, such as adenomatous polyposis coli and end-binding protein 1 (also known as MAPRE1) microtubule-based motors of the kinesin and dynein superfamilies and multiple kinases, such as glycogen synthase kinase 3, LKB1 (also known as STK11) and LKB1's interacting partner STRAD. Phosphoinositide 3-kinase (PI3K) signalling, local actin instability in growth cones and the selective stabilization of microtubules in a particular neurite have emerged as crucial events triggering axon specification. One of the key questions of neurobiology is how neurons polarize to acquire two molecularly and functionally distinct compartments that emerge from the cell body: a single axon and multiple dendrites, which provide the basis for unidirectional signal transmission in the mature nervous system.Ĭultures of hippocampal pyramidal neurons have been used as a model system to analyse the cellular and molecular mechanisms that underlie the development and maintenance of neuronal polarity.
0 kommentar(er)
