A Golgi analysis of the primate globus pallidus. III. Spatial organization of the striato‐pallidal complex

Abstract

An atlas of transverse sections of the globus pallidus and striatum was established in macaque with reference to ventricular coordinates. The three-dimensional geometry of the striato-pallidal complex was investigated by means of sagittal and horizontal reconstructions. Both a personal case studied with autoradiography and data from literature were used to analyze the distribution of cortical axons into the striatum. One may distinguish two striatal territories: one, somatotopically arranged, sensorimotor territory extending over the major part of the putamen; and the other, an associative territory, comprising the caudate nucleus and antero-medial and postero-inferior parts of the putamen. The striato-pallido-nigral bundle was studied using Golgi, Perls, and Fink-Heimer techniques. The bundle is described in four parts: prepallidal (subdivided into caudato-pallidal and putamino-pallidal subparts), transpallidal, pallido-nigral, and nigral. The tracing of the limit between the caudate (associative) and putaminal (essentially sensorimotor) territories shows that the two components are of roughly the same size in the pallidum. The data were compared with geometry and orientation of the dendritic arborizations of large pallidal neurons analyzed in Yelnik et al. ('84). Each pallidal dendritic disc is able to receive axons from a wide region of the striatum. This leads to a convergence on pallidal neurons of striatal axons from different striatal somatotopic strips and from the sensorimotor and associative territories. This is an indication that the globus pallidus may have an integrative role.

Neuronal Reward and Decision Signals: From Theories to Data

“…The anatomical basis may be the triad arrangement of dopamine synapses on glutamatergic inputs to dendritic spines of striatal and cortical neurons (FIGURE 17B) (171,186) and convergence in striatum and globus pallidus (416,430). The long debated focusing effect assumes that dopamine signals suppress the effects of weaker inputs to the striatum while allowing stronger ones to pass through to the basal ganglia outputs (70,368,594).…”

“…For neuronal decision models involving the basal ganglia, key features are the well-organized corticostriatal projections, internal connections, and parallel loops with cortex (7,141,164,196,197,252); the synaptic convergence through the component structures (FIGURE 48B) (416,430); the separate striatal outputs with sequential inhibitory neurons (93,127); and the dopamine-mediated plasticity of corticostriatal connections (424,517,540). The basal ganglia may be involved in two distinguishable aspects of decision-making, namely, the direct selection of options and the updating of option values through reinforcement learning (57).…”

“…Option selection in the basal ganglia employs the dopamine focusing effect (70,368,594) and anatomical convergence in striatum and globus pallidus (416,430) (FIGURE 47). The models employ physiological activities and known input-output relationships of basal ganglia nuclei to demonstrate the feasibility of movement selection (72).…”

A three-dimensional, histological and deformable atlas of the human basal ganglia. I. Atlas construction based on immunohistochemical and MRI data

“…These subdivisions are based on the nature of the cortical information that is processed in different regions of the basal ganglia. Tracing experiments in the monkey have demonstrated that the primary somatosensory, primary motor, premotor and oculomotor cortices project mainly to the putamen in the form of three somatotopic strips corresponding to the arm, face and leg (Flaherty and Graybiel, 1994;Künzle, 1975;Percheron et al, 1984). This subdivision which processes sensorimotor information is referred to as the sensorimotor territory.…”

Visual and oculomotor functions of the monkey subthalamic nucleus

“…Inputs to STN are multiple. Signals arising from the caudate and putamen are conveyed to STN via the external segment of the globus pallidus (Kim et al 1976;Kita et al 1983;Moriizumi et al 1987;Percheron et al 1984). The cerebral cortex is another source of input.…”