Anterior trigeminothalamic tract

The anterior trigeminothalamic tract (or ventral trigeminothalamic tract) is a tract composed of second order neuronal axons. These fibers carry sensory information about discriminative and crude touch, conscious proprioception, pain, and temperature from the head, face, and oral cavity. The anterior trigeminothalamic tract connects the principal (chief sensory) nucleus and spinal trigeminal nucleus to the ventral posteromedial (VPM) nucleus of the thalamus.

The anterior trigeminothalamic tract is also called the anterior trigeminal lemniscus.[1]

Anterior trigeminothalamic tract
Details
SystemSensory system
Fromhead, face, and oral cavity via principal (chief sensory) nucleus and spinal trigeminal nucleus
Toventral posteromedial (VPM) nucleus of the thalamus
Functioncarry sensory information about discriminative and crude touch, conscious proprioception, pain, and temperature from the head, face, and oral cavity
Identifiers
Latintractus trigeminothalamicus anterior
NeuroNames613
TAA14.1.05.311
FMA72506
Anatomical terms of neuroanatomy

Structure

The first order neurons (from the trigeminal ganglion) enter the pons and synapse in the principal (chief sensory) nucleus or spinal trigeminal nucleus. Axons of the second order neurons cross the midline and terminate in the ventral posteromedial nucleus of the contralateral thalamus (as opposed to the ventral posterolateral nucleus, as in the dorsal column medial lemniscus (DCML) system). The third order neuron in the thalamus then connects to the sensory cortex of the postcentral gyrus.

References

  1. ^ Anthoney, T. R. (1993). Neuroanatomy and the neurologic exam: a thesaurus of synonyms, similar-sounding non-synonyms, and terms of variable meaning. CRC Press.

Sources

  • Anthoney, T. R. (1993). Neuroanatomy and the neurologic exam: a thesaurus of synonyms, similar-sounding non-synonyms, and terms of variable meaning. CRC Press.
  • Norton, N. S. (2016). Netter's head and neck anatomy for dentistry. Elsevier Health Sciences.

External links

Acoustic radiation

The acoustic radiations or auditory radiations are structures found in the brain, in the ventral cochlear pathway, a part of the auditory system.

Acoustic radiation arising in the medial geniculate nucleus and end in primary auditory cortex (transverse temporal gyri).

Lesions to the auditory radiations could be a cause of cortical deafness.

Ansa lenticularis

The ansa lenticularis (ansa lentiformis in older texts) is a part of the brain, making up the superior layer of the substantia innominata. Its fibers, derived from the medullary lamina of the lentiform nucleus, pass medially to end in the thalamus and subthalamic region, while others are said to end in the tegmentum and red nucleus.

It is classified by NeuroNames as part of the subthalamus.

Dentatothalamic tract

The dentatothalamic tract (or dentatorubrothalamic tract) is a tract which connects the dentate nucleus and the thalamus while sending collaterals to the red nucleus.The term "dentatorubrothalamocortical" is sometimes used to emphasize termination in the cerebral cortex.

Epithalamus

The epithalamus is a (dorsal) posterior segment of the diencephalon. The diencephalon is a part of the forebrain that also contains the thalamus, the hypothalamus and pituitary gland.

The epithalamus includes the habenula and their interconnecting fibers, the habenular commissure, the stria medullaris and the pineal gland.

Lateral nuclear group

The lateral nuclear group is a collection of nuclei on the lateral side of the thalamus. According to MeSH, it consists of the following:

lateral dorsal nucleus

lateral posterior nucleus

pulvinar

Lateral posterior nucleus of thalamus

The lateral posterior nucleus is a nucleus of the thalamus.

It acts in concert with the pulvinar.

Lenticular fasciculus

The lenticular fasciculus is a tract connecting the globus pallidus to the thalamic fasciculus. It is synonymous with field H2 of Forel. The thalamic fasciculus is (composed of the lenticular fasciculus and ansa lenticularis) runs into the thalamus.

It connects the globus pallidus to the thalamus.

Parvocellular cell

Parvocellular cells, also called P-cells, are neurons located within the parvocellular layers of the lateral geniculate nucleus (LGN) of the thalamus. "Parvus" means "small" in Latin, and the name "parvocellular" refers to the small size of the cell compared to the larger magnocellular cells. Phylogenetically, parvocellular neurons are more modern than magnocellular ones.

Posterior nucleus of hypothalamus

The posterior nucleus of the hypothalamus is one of the many nuclei that make up the hypothalamic region of the brain.

Its function is thermoregulation (heating) of the body.

Damage or destruction of this nucleus causes hypothermia. Descending efferents from the nucleus synapse on the sympathetic neurons of the spinal cord, which exist in the thoracic and lumbar regions in the lateral horns.

Principal sensory nucleus of trigeminal nerve

The principal sensory nucleus (or chief sensory nucleus of V) is a group of second order neurons which have cell bodies in the caudal pons.

It receives information about discriminative sensation and light touch of the face as well as conscious proprioception of the jaw via first order neurons of CN V.

Most of the sensory information crosses the midline and travels to the contralateral ventral posteromedial nucleus (VPM) of the thalamus via the anterior trigeminothalamic tract.

However, information of the oral cavity travels to the ipsilateral VPM of the thalamus via the dorsal trigeminothalamic tract.

Spinal trigeminal nucleus

The spinal trigeminal nucleus is a nucleus in the medulla that receives information about deep/crude touch, pain, and temperature from the ipsilateral face. In addition to the trigeminal nerve (CN V), the facial (CN VII), glossopharyngeal (CN IX), and vagus nerves (CN X) also convey pain information from their areas to the spinal trigeminal nucleus. Thus the spinal trigeminal nucleus receives input from cranial nerves V, VII, IX, and X.

The spinal nucleus is composed of three subnuclei: subnucleus oralis (pars oralis), subnucleus caudalis (pars caudalis), and subnucleus interpolaris (pars interpolaris). The subnucleus oralis is associated with the transmission of discriminative (fine) tactile sense from the orofacial region, and is continuous with the principal sensory nucleus of V. The subnucleus interpolaris is also associated with the transmission of tactile sense, as well as dental pain, whereas the subnucleus caudalis is associated with the transmission of nociception and thermal sensations from the head.

This region is also denoted at sp5 in other neuroanatomical nomenclature.This nucleus projects to the ventral posteriomedial (VPM) nucleus in the contralateral thalamus via the anterior trigeminothalamic tract. In mice, this thalamic nucleus has significant amounts of expression of leptin receptors, NPY and GLP-1.

Stria medullaris of thalamus

The stria medullaris is a part of the epithalamus. It is a fiber bundle containing afferent fibers from the septal nuclei, lateral preoptico-hypothalamic region, and anterior thalamic nuclei to the habenula. It forms a horizontal ridge on the medial surface of the thalamus, and is found on the border between dorsal and medial surfaces of thalamus. Superior and lateral to habenular trigone.

It projects to the habenular nuclei,

from anterior perforated substance and hypothalamus, to habenular trigone, to habenular commissure, to habenular nucleus.

Subthalamic fasciculus

The subthalamic fasciculus is a tract which connects the subthalamic nucleus (STN) and the globus pallidus (GP).

It is a bidirectional connection between the GP and the subthalamic nucleus, including (1) fibers running from the GPe to the subthalamic nucleus, and (2) fibers running from the STN back to the GP.

Subthalamus

The subthalamus or prethalamus is a part of the diencephalon. Its most prominent structure is the subthalamic nucleus. The subthalamus connects to the globus pallidus, a basal nucleus of the telencephalon.

Taenia thalami

In the front, superior surface of the thalamus but separate from the inner, medial surface by a salient margin is the taenia thalami (Latin for "flat band" of the thalamus). The bottom epithelial lining of the third ventricle is in between the tela choroidea and the taenia thalami.

Thalamic fasciculus

The thalamic fasciculus is a component of the subthalamus. It is synonymous with field H1 of Forel. Nerve fibres form a tract containing cerebellothalamic (crossed) and pallidothalamic (uncrossed) fibres, that is insinuated between the thalamus and the zona incerta.

The thalamic fasciculus consists of fibers from the ansa lenticularis and from the lenticular fasciculus, coming from different portions of the medial globus pallidus, before they jointly enter the ventral anterior nucleus of the thalamus.

Ventral anterior nucleus

The ventral anterior nucleus (VA) is a nucleus of the thalamus. It acts with the anterior part of the ventral lateral nucleus to modify signals from the basal ganglia.

Ventral posterior nucleus

The ventral posterior nucleus is the somato-sensory relay nucleus in thalamus of the brain.

Ventral posteromedial nucleus

The ventral posteromedial nucleus (VPM) is a nucleus of the thalamus.

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