Search results
Results from the WOW.Com Content Network
The maturation of myelination in intracortical layers coincides with critical period closure in mice, which has led to further research on the role of myelination on critical period duration. [37] Myelin is known to bind many different axonal growth inhibitors that prevent plasticity seen in critical periods. [38]
Myelin is formed by oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system.Therefore, the first stage of myelinogenesis is often defined as the differentiation of oligodendrocyte progenitor cells (OPCs) or Schwann cell progenitors into their mature counterparts, [4] followed by myelin formation around axons.
Myelinated axons only allow action potentials to occur at the unmyelinated nodes of Ranvier that occur between the myelinated internodes. It is by this restriction that saltatory conduction propagates an action potential along the axon of a neuron at rates significantly higher than would be possible in unmyelinated axons (150 m/s compared from 0.5 to 10 m/s). [1]
Miyake and Friedman's theory of executive functions proposes that there are three aspects of executive functions: updating, inhibition, and shifting. [63] A cornerstone of this theoretical framework is the understanding that individual differences in executive functions reflect both unity (i.e., common EF skills) and diversity of each component ...
Myelin's best known function is to increase the rate at which information, encoded as electrical charges, passes along the axon's length. Myelin achieves this by eliciting saltatory conduction. [1] Saltatory conduction refers to the fact that electrical impulses 'jump' along the axon, over long myelin sheaths, from one node of Ranvier to the next.
Myelin sheath reduces membrane capacitance and increases membrane resistance in the inter-node intervals, thus allowing a fast, saltatory movement of action potentials from node to node. [l] [m] [n] Myelination is found mainly in vertebrates, but an analogous system has been discovered in a few invertebrates, such as some species of shrimp.
A model view of the synapse. Synaptic pruning, a phase in the development of the nervous system, is the process of synapse elimination that occurs between early childhood and the onset of puberty in many mammals, including humans. [1]
Polyvagal theory (PVT) is a collection of proposed evolutionary, neuroscientific, and psychological constructs pertaining to the role of the vagus nerve in emotion regulation, social connection and fear response.