Editing Putamen (section)

==Anatomy==
[[File:Globus pallidus and putamen - very low mag.jpg|thumb|right|Globus pallidus (lower left) and putamen (upper right). [[LFB stain|H&E-LFB stain]].]]
The putamen is a structure in the [[forebrain]]. Along with the [[caudate nucleus]] it forms the [[dorsal striatum]]. The caudate and putamen contain the same types of neurons and circuits – many neuroanatomists consider the dorsal striatum to be a single structure, divided into two parts by a large fiber tract, the [[internal capsule]], passing through the middle. The putamen, together with the [[globus pallidus]], makes up the [[lentiform nucleus]]. The putamen is the outermost portion of the [[basal ganglia]]. These are a group of nuclei in the brain that are interconnected with the [[cerebral cortex]], [[thalamus]], and [[brainstem]]. The basal ganglia include the [[striatum]], [[substantia nigra]], [[nucleus accumbens]], and the [[subthalamic nucleus]].

In [[mammals]], the basal ganglia are associated with [[motor control]], [[cognition]], [[emotion]]s, [[learning]], and domain-general functions important for executive functioning as well as support for domain-specific languages. The basal ganglia are located bilaterally, and have [[Rostral and caudal|rostral, and caudal]] divisions. The putamen is located in the rostral division as part of the [[striatum]]. The basal ganglia receive input from the cerebral cortex, via the striatum.

[[File:Striatum Structural MRI.png|thumb|alt=This is a transverse section of the striatum from a structural MR image. The striatum includes the [[caudate nucleus]] (top) and putamen (right) and the [[globus pallidus]] (left).|This is a transverse section of the striatum from a structural MR image. The striatum includes the caudate nucleus (top) and putamen (right) and the globus pallidus (left).]]

===Caudate nucleus===
The caudate works with the putamen to receive the input from [[cerebral cortex]]. Collectively, they can be considered the "entrance" to the basal ganglia. Projections from the putamen reach the caudate directly via the caudolenticular grey bridges. The putamen and caudate are jointly connected with the [[substantia nigra]], however the caudate outputs more densely to the [[substantia nigra]] pars reticulata while the putamen sends more afferents to the internal [[globus pallidus]].

===Substantia nigra===
The substantia nigra contains two parts: the substantia nigra pars compacta (SNpc) and the substantia nigra pars reticulata (SNpr). The SNpc obtains input from the putamen and caudate, and sends information back. The SNpr also obtains input from the putamen and caudate. However, it sends the input outside the basal ganglia to control head and [[Eye movement (sensory)|eye movement]]s. The SNpc produces dopamine, which is crucial for movements. The SNpc degenerates during [[Parkinson's disease]].<ref name="Alexander">{{cite journal | journal =  Trends in Neurosciences|date=July 1990 | volume = 13 | issue = 7 | pages = 266–71 | title = Functional architecture of basal ganglia circuits: neural substrates of parallel processing | author = Alexander GE |author2=Crutcher MD  | pmid = 1695401 | doi =10.1016/0166-2236(90)90107-L |s2cid=3990601 }}</ref>

===Globus pallidus===
The globus pallidus contains two parts: the [[external globus pallidus]] (GPe) and the [[internal globus pallidus]] (GPi). Both regions acquire input from the putamen and caudate and communicate with the subthalamic nucleus. However, mostly the GPi sends GABAergic inhibitory output to the thalamus. The GPi also sends projections to parts of the midbrain, which have been assumed to affect posture control.<ref name="Alexander" />