The striosomes (also referred to as striatal patches) are one of two complementary chemical compartments within the

striatum The striatum (: striata) or corpus striatum is a cluster of interconnected nuclei that make up the largest structure of the subcortical basal ganglia. The striatum is a critical component of the motor and reward systems; receives glutamat ...

(the other compartment is known as the matrix) that can be visualized by staining for immunocytochemical markers such as mu opioid receptors,

acetylcholinesterase Acetylcholinesterase (HUGO Gene Nomenclature Committee, HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme th ...

enkephalin An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed endogenous ligands, as they are internally derived (and therefore endogenous) and bind as ligands to the body's opioid ...

substance P Substance P (SP) is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) and a type of neuropeptide, belonging to the tachykinin family of neuropeptides. It acts as a neurotransmitter and a neuromodulator. Substance P ...

, limbic system-associated membrane protein (LAMP), AMPA receptor subunit 1 (GluR1),

dopamine receptor Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through diff ...

subunits, and

calcium binding protein Calcium-binding proteins are proteins that participate in calcium cell signaling pathways by binding to Ca2+, the calcium ion that plays an important role in many cellular processes. Calcium-binding proteins have specific domains that bind to calci ...

s. Striosomal abnormalities have been associated with

neurological disorders Neurological disorders represent a complex array of medical conditions that fundamentally disrupt the functioning of the nervous system. These Disorder of consciousness, disorders affect the brain, spinal cord, and nerve networks, presenting unique ...

, such as mood dysfunction in

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is an incurable neurodegenerative disease that is mostly Genetic disorder#Autosomal dominant, inherited. It typically presents as a triad of progressive psychiatric, cognitive, and ...

, though their precise function remains unknown. Recently studies have identified the presence of "exo-patch" neurons that are biochemically and genetically the same as striosomal neurons, but reside in the matrix compartment. This study also characterized the different input and output connections of the striosome and matrix compartments, revealing that both regions have direct inputs to dopamine neurons (though the striosome inputs are somatic whereas the matrix targets distal dendrites). The authors also revealed unique inputs to the striosome from subcortical limbic structures like the

amygdala The amygdala (; : amygdalae or amygdalas; also '; Latin from Greek language, Greek, , ', 'almond', 'tonsil') is a paired nucleus (neuroanatomy), nuclear complex present in the Cerebral hemisphere, cerebral hemispheres of vertebrates. It is c ...

and

bed nucleus of the stria terminalis The stria terminalis (or terminal stria) is a structure in the brain consisting of a band of fibers running along the lateral margin of the ventricular surface of the thalamus. Serving as a major output pathway of the amygdala, the stria termina ...

. Striosomes were discovered by Candace Pert in 1976 based on mu opioid receptor

autoradiography An autoradiograph is an image on an X-ray film or nuclear emulsion produced by the pattern of decay emissions (e.g., beta particles or gamma rays) from a distribution of a radioactive substance. Alternatively, the autoradiograph is also availab ...

and

Ann Graybiel Ann Martin Graybiel (born 1942) is an Institute Professor and a faculty member in the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology. She is also an investigator at the McGovern Institute for Brain Resear ...

in 1978 using acetylcholinesterase

histochemistry Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of antibodies binding specifically to antigens in biological tissues. Albert Hewett ...

References

External links

*{{cite web , last=Trafton , first=Anne , title=Study helps explain why motivation to learn declines with age , website=MIT News | Massachusetts Institute of Technology , date=2020-10-27 , url=https://news.mit.edu/2020/why-learn-motivate-age-decline-1027 , access-date=2020-10-29 Article on striosomes' role in age-related decline in learning. Basal ganglia