The history of basal ganglia anatomy

Abstract

The basal ganglia anatomo-functional system is a recent concept. While some of the basal ganglia are anatomically depicted in ancient anatomical treatises, morphological descriptions of the deep gray-matter nuclei of the brain did not really begin until the 17th century. Major discoveries were made simultaneously by several authors: Thomas Willis (1621–1675), Felix Vicq d’Azyr (1748–1794), Christian Reil (1759–1813) and Karl Friedrich Burdach (1776–1847), amongst others, made major contributions to the morphological descriptions of the structures now known as the lenticularis and caudate nuclei, thalamus and substantia nigra. By the end of the 19th century, Jules Bernard Luys (1828–1879) had described the subthalamic nucleus, and Auguste Forel (1848–1931) had provided a thorough description of the subthalamic region. Jules Dejerine's (1849–1917) anatomical work emphasized the morphological organization of the encephalic deep gray matter. A few years later, Charles Foix (1882–1927) and Jean Nicolesco (1895–1957) published a reference anatomical work on the gray matter of the brain, subthalamic region and brainstem. Their accurate descriptions of the anatomical pathways were the starting points of our understanding of the basal ganglia and the pathophysiology of Parkinson's disease. The functional anatomy of the basal ganglia circuits was subsequently specified, in particular by Garrett Alexander and Michael Crutcher. More recent anatomo-functional studies have highlighted the non-motor functions of the basal ganglia system. They also focus on several new nuclei, such as the nucleus accumbens septi, now regarded as a stereotactic surgery target, and the pedunculopontine tegmental nucleus, which seems to be one of the key nuclei of the basal ganglia system.