caudate nucleus

Brain: Caudate nucleus
Transverse Cut of Brain (Horizontal Section), basal ganglia is blue
Latin	nucleus caudatus
Gray's	subject #189 833
NeuroNames	hier-208
MeSH	Caudate+Nucleus
NeuroLex ID	birnlex_1373

The caudate nucleus is a nucleus located within the basal ganglia of the brains of many animal species. The caudate nucleus is an important part of the brain's learning and memory system.

Anatomy

Caudate nucleus

The caudate nuclei are located near the center of the brain, sitting astride the thalamus. There is a caudate nucleus within each hemisphere of the brain. Individually, they resemble a C-shape structure with a wider head at the front, tapering to a body and a tail. (Sometimes a part of the caudate nucleus is referred to as genu ^[1]).

The head and body of the caudate nucleus form part of the floor of the anterior horn of the lateral ventricle. After the body travels briefly towards the back of the head, the tail curves back toward the anterior, forming the roof of the inferior horn of the lateral ventricle. This means that a coronal (on the same plane as the face) section that cuts through the tail will also cross the body (or head) of the caudate nucleus.

The caudate nucleus is related anatomically to a number of other structures. It is separated from the lenticular nucleus (made up of the globus pallidus and the putamen) by the anterior limb of the internal capsule. Together the caudate and putamen form the dorsal striatum.

Neurochemistry

The caudate nucleus is highly innervated by dopamine neurons. These neurons originate mainly from the ventral tegmental area (VTA) and the substantia nigra pars compacta (SNc). There are also additional inputs from various association cortices.

Physiology

Learning and Memory

Historically, the basal ganglia as a whole have been implicated in higher-order motor control.^[2] The caudate nucleus was initially thought to primarily be involved with control of voluntary movement. More recently, it has been demonstrated that the caudate is highly involved in learning and memory,^[3] particularly regarding feedback processing.^[4] In general, it has been demonstrated that neural activity will be present within the caudate while an individual is receiving feedback.

Language Comprehension

The left caudate in particular has been suggested to have a relationship with the thalamus that governs the comprehension and articulation of words as they are switched between languages.^{[5] [6]}

Threshold control

The brain contains large collections of neurons reciprocally connected by excitatory synapses, thus forming large network of elements with positive feedback. It is difficult to see how such a system can operate without some mechanism to prevent explosive activation. There is some indirect evidence^[7] that the caudate may perform this regulatory role by measuring the general activity of cerebral cortex and controlling the threshold potential.

Role in Obsessive Compulsive Disorder

It has been theorized that the caudate nucleus may be dysfunctional in persons with obsessive compulsive disorder (OCD), in that it may perhaps be unable to properly regulate the transmission of information regarding worrying events or ideas between the thalamus and the orbitofrontal cortex.

A neuroimaging study with positron emission tomography found that the right caudate nucleus had the largest change in glucose metabolism after patients had been treated with paroxetine.^[8] A recent meta-analysis of voxel-based morphometry studies comparing people with OCD and healthy controls has found people with OCD to have increased grey matter volumes in bilateral lenticular nuclei, extending to the caudate nuclei, while decreased grey matter volumes in bilateral dorsal medial frontal/anterior cingulate gyri.^[9]

Additional images

Diagram of hippocampus	Velum interpositum.	Schematic representation of the chief ganglionic categories (I to V).	Superficial dissection of brain-stem. Lateral view.
Dissection of brain-stem. Lateral view.	Deep dissection of brain-stem. Lateral view.	Deep dissection of brain-stem. Lateral view.	Superficial dissection of brain-stem. Ventral view.
Dissection of brain-stem. Dorsal view.	Dissection showing the ventricles of the brain.	Coronal section of brain immediately in front of pons.	Coronal section of brain through intermediate mass of third ventricle.
Coronal section of lateral and third ventricles.	Section of brain showing upper surface of temporal lobe.	Central part and anterior and posterior cornua of lateral ventricles exposed from above.	Two views of a model of the striatum (on the right side of the brain): A, lateral aspect; B, medial aspect.
Coronal section through anterior cornua of lateral ventricles.	Coronal section of brain through anterior commissure.	Coronal section of inferior horn of lateral ventricle.	Human brain left dissected midsagittal view
Human brain right dissected lateral view	purple=caudate, orange=putamen

References

External links

• BrainMaps at UCDavis caudate nucleus

• Diagram at uni-tuebingen.de
• NIF Search - Caudate Nucleus via the Neuroscience Information Framework