γ-motoneurons are located in the brainstem and spinal cord and are smaller than their α-motoneuron counterparts, which are responsible for controlling skeletal muscle.

They are also found on the terminal axons of primary afferents within laminae I and II ( substantia gelatinosa ) of the spinal cord and in the spinal nucleus of the trigeminal nerve.

If the syrinx is higher up in the spinal cord or affecting the brainstem as in syringobulbia, vocal cord paralysis, ipsilateral tongue wasting, trigeminal nerve sensory loss, and other signs may occur.

It is caused by an underlying collection of gray matter known as the spinal nucleus of the trigeminal nerve.

The gray matter of this nucleus is covered by a layer of nerve fibers that form the spinal tract of the trigeminal nerve.

** The spinal trigeminal nerve nuclei which contains the general somatic afferent column ( GSA ).

The alar plate produces sensory neuroblasts, which will give rise to the solitary nucleus and its special visceral afferent ( SVA ) column, the cochlear and vestibular nuclei — which form the special somatic afferent ( SSA ) fibers of the vestibulocochlear nerve —, the spinal and principal trigeminal nerve nuclei — which form the general somatic afferent column ( GSA ) of the trigeminal nerve —, and the pontine nuclei which relays to the cerebellum.

The trigeminal ganglion is analogous to the dorsal root ganglia of the spinal cord, which contain the cell bodies of incoming sensory fibers from the rest of the body.

C = cervical segment, S = sacral segment, VPL = ventral posterolateral nucleus, SI = primary somatosensory cortex, VM = ventromedial prefrontal cortex, MD = medial dorsal thalamic nucleus, IL = intralaminar nucleus, VPM = ventral posteromedial nucleus, Main V = main trigeminal nucleus, Spinal V = spinal trigeminal nucleus

The trigeminal nucleus extends throughout the entire brainstem, from the midbrain to the medulla, and continues into the cervical cord, where it merges with the dorsal horn cells of the spinal cord.

From caudal to rostral ( i. e., going up from the medulla to the midbrain ) they are the spinal trigeminal nucleus, the main trigeminal nucleus, and the mesencephalic trigeminal nucleus.

The spinal trigeminal nucleus receives pain / temperature fibers.

The spinal trigeminal nucleus represents pain / temperature sensation from the face.

On entering the brainstem, sensory fibers are grouped together and sent to the spinal trigeminal nucleus.

This bundle of incoming fibers can be identified in cross sections of the pons and medulla as the spinal tract of the trigeminal nucleus, which parallels the spinal trigeminal nucleus itself.

The spinal trigeminal nucleus contains a pain / temperature sensory map of the face and mouth.

The central analgesia system is mediated by 3 major components: the periaquaductal grey matter, the nucleus raphe magnus and the nociception inhibitory neurons within the dorsal horns of the spinal cord, which act to inhibit nociception-transmitting neurons also located in the spinal dorsal horn.

Grey matter is distributed at the surface of the cerebral hemispheres ( cerebral cortex ) and of the cerebellum ( cerebellar cortex ), as well as in the depths of the cerebrum ( thalamus ; hypothalamus ; subthalamus, basal ganglia-putamen, globus pallidus, nucleus accumbens ; septal nuclei ), cerebellar ( deep cerebellar nuclei-dentate nucleus, globose nucleus, emboliform nucleus, fastigial nucleus ), brainstem ( substantia nigra, red nucleus, olivary nuclei, cranial nerve nuclei ) and spinal grey matter ( anterior horn, lateral horn, posterior horn ).

Functional imaging upon placebo analgesia shows that it links to the activation, and increased functional correlation between this activation, in the anterior cingulate, prefrontal, orbitofrontal and insular cortices, nucleus accumbens, amygdala, the brainstem periaqueductal gray matter, and the spinal cord.

This area receives input from the hypothalamus, amygdala, and raphe nucleus among other regions and projects widely across the brain as well as to the spinal cord.

It originates in Onuf's nucleus in the sacral region of the spinal cord, and travels in the S2-S4 nerves of the sacral plexus.

Preganglionic parasympathetic neurons are in the medulla oblongata ( forming visceral motor nuclei: the dorsal motor nucleus of the vagus nerve ( dmnX ), the nucleus ambiguus, and salivatory nuclei ) and in the sacral spinal cord.

Neurons synapse here and, when stimulated, cause activation of neurons in the nucleus raphe magnus, which then project down into the dorsal horn of the spinal cord and prevent pain sensation transmission.

A number of specialized types of neurons exist: sensory neurons respond to touch, sound, light and numerous other stimuli affecting cells of the sensory organs that then send signals to the spinal cord and brain.

* Anterior horn cells, motoneurons located in the spinal cord.

There the axon makes excitatory synaptic contacts with other cells, some of which project ( send axonal output ) to the same region of the spinal cord, others projecting into the brain.

For example, in neurogenesis, a subpopulation of ectoderm cells is set aside to become the brain, spinal cord, and peripheral nerves.

A number of specialized types of neurons exist: sensory neurons respond to touch, sound, light and numerous other stimuli affecting cells of the sensory organs that then send signals to the spinal cord and brain.

A brain tumor, or tumour, is an intracranial solid neoplasm, a tumor ( defined as an abnormal growth of cells ) within the brain or the central spinal canal.

MS affects the ability of nerve cells in the brain and spinal cord to communicate with each other effectively.

** Spinal cord, the bundle of nerve cells and nerve fibers within the vertebral column subject to spinal cord injury

# Layer V, the Internal Pyramidal layer, contains large pyramidal neurons ( such as the Betz cells in the primary motor cortex ); it is the principal source of subcortical efferents, as such, there are large pyramidal cells which give rise to axons leaving the cortex and running down through the basal ganglia, the brain stem and the spinal cord.

When a nerve impulse reaches the spinal cord, endorphins that prevent nerve cells from releasing more pain signals are released.

*-" Nervous Tissue and Neuromuscular Junction: spinal cord, cell bodies of anterior horn cells "

However, magnetic resonance imaging has shown that when a person is undergoing an MS " attack ," the blood – brain barrier has broken down in a section of the brain or spinal cord, allowing white blood cells called T lymphocytes to cross over and attack the myelin.

However, the concept of head transplantation may become more popular, as stem cells have been shown by the Wistar Institute of the University of Pennsylvania to repair the severed spinal cords of mice to a functional level.

There are four subdivisions of the neural tube that will each eventually develop into distinct regions of the central nervous system by the division of neuroepithelial cells: The prosencephalon, the mesencephalon, the rhombencephalon and the spinal cord.

However, adult apteronotids are one exception, as their electric organs are derived from nerve cells ( spinal electromotor neurons ).

This is a type of specialized brain and body scan used to map neural activity in the brain or spinal cord of humans or animals by imaging the change in blood flow ( hemodynamic response ) related to energy use by brain cells.

Early in development, this plate of cells forms the neural tube, a narrow sheath that closes between the third and fourth weeks of pregnancy to form the brain and spinal cord of the embryo.

Poliovirus attacks specific neurons in the brainstem and the anterior horn cells of the spinal cord, generally resulting in the death of a substantial fraction of the motor neurons controlling skeletal muscles.

Their main functions are to provide support and to insulate the axons ( the long projection of nerve cells ) in the central nervous system ( the brain and spinal cord ) of some vertebrates.

Spinal muscular atrophies are a genetically and clinically heterogeneous group of rare debilitating disorders characterised by degeneration of lower motor neurons – that is, neuronal cells situated in the anterior horn of spinal cord – and subsequent atrophy ( wasting ) of various muscle groups in the body.

TOCP was originally thought to be non-toxic ; however, it was later determined to be a neurotoxin that causes axonal damage to the nerve cells in the nervous system of human beings, especially those located in the spinal cord.