Magnocellular part
Encyclopedia
Magnocellular cells, also called M-cells, are neuron
s located within the magnocellular layer of the lateral geniculate nucleus
of the thalamus
. The cells are part of the visual system
. They are termed "magnocellular" since they are characterized by their relatively large size compared to parvocellular cells.
Magnocellular cells are primarily concerned with visual perception
. In particular these cells are responsible for resolving motion and coarse outlines. The M-cells receive their information from the axons of parasol cell
s exiting the optic tract
. The M-cells are large, fast-conducting neuron
s with their cell bodies located in the 2 ventral magnocellular layers of the lateral geniculate nucleus
. The information they carry is sent through the optic radiation
s to the visual cortices, possibly after editing and gating by visual cortex exerting top-down control. The M-cells feed more to the parietal cortices, in the dorsal "where" stream, than the temporal cortices, destination of the ventral "what" stream. This is consistent with their coding of movement and edges as opposed to fine detail. This system of cells operates with great speed at the expense of detail.
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s located within the magnocellular layer of the lateral geniculate nucleus
Lateral geniculate nucleus
The lateral geniculate nucleus is the primary relay center for visual information received from the retina of the eye. The LGN is found inside the thalamus of the brain....
of the thalamus
Thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...
. The cells are part of the visual system
Visual system
The visual system is the part of the central nervous system which enables organisms to process visual detail, as well as enabling several non-image forming photoresponse functions. It interprets information from visible light to build a representation of the surrounding world...
. They are termed "magnocellular" since they are characterized by their relatively large size compared to parvocellular cells.
Visual system
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
. In particular these cells are responsible for resolving motion and coarse outlines. The M-cells receive their information from the axons of parasol cell
Parasol cell
A parasol cell is one type of retinal ganglion cell located in the ganglion cell layer of the retina. Parasol cells project their axons to the magnocellular layers of the lateral geniculate nucleus, where they synapse with magnocellular cells. These cells are known as parasol retinal ganglion...
s exiting the optic tract
Optic tract
The optic tract is a part of the visual system in the brain.It is a continuation of the optic nerve and runs from the optic chiasm to the lateral geniculate nucleus....
. The M-cells are large, fast-conducting neuron
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...
s with their cell bodies located in the 2 ventral magnocellular layers of the lateral geniculate nucleus
Lateral geniculate nucleus
The lateral geniculate nucleus is the primary relay center for visual information received from the retina of the eye. The LGN is found inside the thalamus of the brain....
. The information they carry is sent through the optic radiation
Optic radiation
The optic radiation is a collection of axons from relay neurons in the lateral geniculate nucleus of the thalamus carrying visual information to the visual cortex along the calcarine fissure.There is one such tract on each side of the brain.-Parts:A distinctive...
s to the visual cortices, possibly after editing and gating by visual cortex exerting top-down control. The M-cells feed more to the parietal cortices, in the dorsal "where" stream, than the temporal cortices, destination of the ventral "what" stream. This is consistent with their coding of movement and edges as opposed to fine detail. This system of cells operates with great speed at the expense of detail.
External links
- NIF Search - Magnocellular Cell via the Neuroscience Information FrameworkNeuroscience Information FrameworkThe Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/genomic resources.-Description:...