Basal ganglia
The basal ganglia (or basal nuclei) are three areas under the cerebral cortex. They are part of the cerebrum (forebrain), and connected to the midbrain and the thalamus. They are vital to movement, and damage here results is damaged ability to move.
The three areas are:
- striatum
- caudate nucleus
- putamen
- pallidum (or globus pallidus)
- substantia nigra
- nucleus accubens
- subthalamic nucleus
The range of behaviours controlled by the nuclei is wide. They control eye movements.[1] They do voluntary motor control, learning procedures for routine behaviors or "habits", and cognitive emotional functions.[2][3]
The basal ganglia also control motivation. They select actions, that is, the choice of what to do at a given time.[2][4] Experimental studies show that the basal ganglia inhibit (suppress) a number of motor systems. A release of this inhibition lets a motor system act. This "behaviour switching" is influenced by signals from many parts of the brain, including the prefrontal cortex, which plays a key role in doing things.[3][5]
Evolution
The basal ganglia form one of the basic components of the forebrain, and can be recognized in all species of vertebrates.[6] Even in the lamprey (one of the most primitive vertebrates) striatal, pallidal, and nigral elements can be identified by their anatomy and histochemistry.[7]
Basal Ganglia Media
- Anatomy of the Basal Ganglia.ogv
The relevant anatomy in 3D.
- Basal-ganglia-coronal-sections-large.png
Coronal slices of human brain showing the basal ganglia. White matter is shown in dark gray, gray matter is shown in light gray.Anterior: striatum, globus pallidus (GPe and GPi)Posterior: subthalamic nucleus (STN), substantia nigra (SN)
- Anatomy of the basal ganglia.jpg
Illustration of the anatomy of the basal ganglia. The globus pallidus lies inside the putamen. The thalamus is located underneath the basal ganglia, in the medial position of the brain.
Location of the substantia nigra within the basal ganglia
Connectivity diagram showing excitatory glutamatergic pathways as red, inhibitory GABAergic pathways as blue, and modulatory dopaminergic pathways as magenta. (Abbreviations: GPe: globus pallidus external; GPi: globus pallidus internal; STN: subthalamic nucleus; SNc: substantia nigra pars compacta; SNr: substantia nigra pars reticulata)
- Basal ganglia coronal sections.gif
Basal ganglia highlighted in green on coronal T1 MRI images
- Basal ganglia sagittal sections.gif
Basal ganglia highlighted in green on sagittal T1 MRI images
Related pages
References
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ 2.0 2.1 Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ 3.0 3.1 Weyhenmeyer, James A.; Gallman, Eve A. (2007). Rapid review of neuroscience. Mosby Elsevier. p. 102. ISBN 978-0-323-02261-3.
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Parent A (1986). Comparative neurobiology of the basal ganglia. Wiley. ISBN 978-0-471-80348-5.
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).