Striosome
The striosomes are one of two complementary chemical compartments within the striatum (the other compartment is known as the matrix) that can be visualized by staining for immunocytochemical markers such as acetylcholinesterase (Graybiel and Ragsdale, 1978), enkephalin, substance P, limbic system-associated membrane protein (LAMP) (Prensa et al., 1999), AMPA receptor subunit 1 (GluR1) (Martin et al., 1993), dopamine receptor subunits, and calcium binding proteins (O'Kusky et al., 1999). Striosomal abnormalities have been associated with neurological disorders, such as mood dysfunction in Huntington’s disease (Tippett et al., 2007), though their precise function remains unknown. Striosomes were discovered by Ann Graybiel in 1978 using acetylcholinesterase histochemistry.