Search results
Results from the WOW.Com Content Network
Confocal microscope image of cerebellar Purkinje cells expressing tdTomato. These cells are some of the largest neurons in the human brain (Betz cells being the largest), [5] with an intricately elaborate dendritic arbor, characterized by a large number of dendritic spines. Purkinje cells are found within the Purkinje layer in the cerebellum.
Nervous tissue, also called neural tissue, is the main tissue component of the nervous system.The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system (PNS) comprising the branching peripheral nerves.
Nissl bodies show changes under various physiological conditions and in pathological conditions such as axonotmesis, during which they may dissolve and largely disappear (chromatolysis). If the neuron is successful in repairing the damage, the Nissl bodies gradually reappear and return to their characteristic distribution within the cell.
For example, in a rat model, large bundles of greater than 20 axons are found exiting the L5 dorsal root ganglion, while smaller bundles of average 3 axons are found in distal nerve segments. [3] Multiple neurons contribute axons to the Remak bundle with an average ratio of about 2 axons contributed per bundle. [ 3 ]
Recent studies using cross-sectional neuroimaging have shown that by around the age of 8 the volume of grey matter begins to decrease. [4] However, the density of grey matter appears to increase as a child develops into early adulthood. [4] Males tend to exhibit grey matter of increased volume but lower density than that of females. [5]
One small study found that men have more white matter than women both in volume and in length of myelinated axons, and that volume and length reduced with age. (This study only included 36 participants. [6]) At the age of 20, the total length of myelinated fibers in men is 176,000 km while that of a woman is 149,000 km.
Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. The neuroglia make up more than one half the volume of neural tissue in the human body. [1]
Oligodendrocytes are a type of glial cell, non-neuronal cells in the central nervous system.They arise during development from oligodendrocyte precursor cells (OPCs), [8] which can be identified by their expression of a number of antigens, including the ganglioside GD3, [9] [10] [11] the NG2 chondroitin sulfate proteoglycan, and the platelet-derived growth factor-alpha receptor subunit (PDGF ...