Search results
Results from the WOW.Com Content Network
In neuroanatomy, a nucleus (pl.: nuclei) is a cluster of neurons in the central nervous system, [1] located deep within the cerebral hemispheres and brainstem. [2] The neurons in one nucleus usually have roughly similar connections and functions. [3]
Neurons such as Purkinje cells in the cerebellum can have over 1000 dendritic branches, making connections with tens of thousands of other cells; other neurons, such as the magnocellular neurons of the supraoptic nucleus, have only one or two dendrites, each of which receives thousands of synapses.
Nuclei are connected to other nuclei by tracts of white matter. Glia are the supporting cells of the neurons and have many functions not all of which are clearly understood, but include providing support and nutrients to the neurons.
Neurons of the SN are notably functionally arranged roughly length-wise along the nucleus: gustatory neurons are situated rostrally (with afferents from the anterior part of the tongue and roof of oral cavity rostral-most, and those from the larynx and epiglottis more caudally placed); gastrointestinal, cardiovascular, respiratory neurons are situated more caudally.
Another area, not on the dorsum of the brainstem, is where the special visceral efferents nuclei reside. These formed from the pharyngeal arches , in the embryo. This area is a bit below the autonomic motor nuclei , and includes the nucleus ambiguus , facial nerve nucleus, as well as the motor part of the trigeminal nerve nucleus.
In the brainstem, α-MNs and other neurons reside within clusters of cells called nuclei, some of which contain the cell bodies of neurons belonging to the cranial nerves. Not all cranial nerve nuclei contain α-MNs; those that do are motor nuclei, while others are sensory nuclei.
Nuclei of the Thalamus Both the left and right hemispheres of the brain have a lateral geniculate nucleus, named after its resemblance to a bent knee ( genu is Latin for "knee"). In humans as well as in many other primates , the LGN has layers of magnocellular cells and parvocellular cells that are interleaved with layers of koniocellular cells.
These neurons are inhibited by leptin, insulin, and peptide YY and activated by ghrelin. Centrally projecting neurons that contain peptide products of pro-opiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART). These neurons have widespread projections to many brain areas, including to all nuclei in the hypothalamus.