Functional anatomy of the basal ganglia

Abstract

Four organizational levels of the basal ganglia that could be particularly determinant in terms of functional properties are reviewed: (1) macroscopic anatomy, which is characterized by a dramatic decrease of cerebral tissue volume from the cerebral cortex to the deepest portions of the basal ganglia; (2) connectivity, which consists of both complex loops and a partition into three territories, sensorimotor, associative, and limbic (which process motor, cognitive, and emotional information, respectively); (3) neuronal morphology, characterized by a dramatic numeric and geometric convergence of striatal neurons onto pallidonigral neurons; and (4) dopaminergic innervation of the basal ganglia, which is organized as a dual system that is supposed to have opposite effects on the activity of the system. Current models of the basal ganglia are discussed.

Reduced functional connectivity between V1 and inferior frontal cortex associated with visuomotor performance in autism

“…The putamen is part of a basal ganglia-thalamocortical loop and receives afferents mostly from primary motor and somatosensory cortices (DeLong, 2000). The group effect seen in the putamen is therefore unlikely to reflect differences in monosynaptic connectivity with V1, but may rather relate to differences in modulatory motor functions of the striatum (Yelnik, 2002).…”

Deep brain stimulation in Parkinson disease—what went wrong?

“…In STN DBS for PD, the stimulating electrodes are aimed at the sensorimotor area of the STN to improve akinesia, rigidity and tremor. However, given the small volume of the STN (160 mm 3 in humans) [34] and the tight intermingling and interactions of the different territories [35], diffusion of the electrical current to associative and limbic areas is common. Here, we review evidence indicating that diffusion of electricity to these areas [36] influences non-motor features of PD and can induce new behavioural or psychiatric symptoms.…”

Psychiatric considerations in deep brain stimulation for Parkinson’s disease

“…Stimulation of the limbicassociative STN (below, anterior, and medial to the sensorimotor STN, which is the optimal motor target) has been associated with both positive and negative mood symptoms (Funkiewiez et al, 2003;Krack et al, 2010). The STN is a small nucleus (180 mm 3 ) (Yelnik, 2002) within the indirect pathway of the corticostriatal circuitry receiving input from the globus pallidus externa and output projections to the substantia nigra pars reticulata and globus pallidus interna, and also receives "hyperdirect" projections from cortical regions (Nambu et al, 2002;Haynes and Haber, 2013). Although the conceptualization of the corticostriatal circuitry is now increasingly complex, it is broadly divided into functional territories, which similarly are functionally subdivided in the STN (Yelnik, 2002).…”

“…The STN is a small nucleus (180 mm 3 ) (Yelnik, 2002) within the indirect pathway of the corticostriatal circuitry receiving input from the globus pallidus externa and output projections to the substantia nigra pars reticulata and globus pallidus interna, and also receives "hyperdirect" projections from cortical regions (Nambu et al, 2002;Haynes and Haber, 2013). Although the conceptualization of the corticostriatal circuitry is now increasingly complex, it is broadly divided into functional territories, which similarly are functionally subdivided in the STN (Yelnik, 2002). Given the small size of the nucleus, current spread is likely to affect the ventromedial cognitive and limbic regions (Krack et al, 2010).…”