On the structure and functional relations of the optic thalamus. By Ernest Sachs, A.B., MD, of New York. From Sir Victor Horsley's Laboratory, Department of Pathological Chemistry, University College, London. Brain 1909: 32; 95 186.

Abstract

Acknowledging the roles of Sir Victor Horsley and Dr R.H. Clarke in suggesting the study and providing the necessary apparatus (see Brain 2007: 130; 1449 – 1452), Dr Sachs starts with an historical account of what is currently known concerning the anatomy and physiology of the thalamus, leaning much on the historical account by Gustave Roussy (La couche optique, 1907). Prior to the pioneering work of Hermann Nothnagel (1874), who first lesioned the thalamus with fluid, discrete but crude areas of damage were created by mechanical probes and electrolytic lesions. This work displaced the erroneous idea dating from Francois Magendie (La systeme nerveux, 1841) that the thalamus is the motor centre to one placing this ganglion as the unconscious reflex centre that relays stimuli from the periphery to form motor images that are the basis for voluntary action. Gradually, through a series of claims (dubious and more plausible), was built up an impressive catalogue of brain functions in which the thalamus plays a role—motor, sensory, autonomic, visual, auditory and behavioural (including a ‘screaming centre’, described by Vladimir Bechterew as ‘Geschrei wie es auf Schmerz auftritt’). Others defined thalamic anatomy but could not agree on the number of nuclei, each having discrete connections with parts of the cortex. Notwithstanding the authority of Constantin von Monakow (1895), Heinrich Obersteiner (1901), Santiago Ramon y Cajal (1902) and Otto Marburg (1904), after spending time in Vienna with Professor Obersteiner and, with help from Horsley, Dr Sachs proposes a classification of seven main thalamic nuclei (anterior, medial, lateral, ventral, centre median, arcuate and pulvinar). Now, he rehearses the state of knowledge concerning connectivities: thalamo-cortical, cortico-thalamic, thalamo-striate and a variety of descending thalamo-fugal projections to the brain stem and medulla but no further. But there is work yet to be done in reconciling the true number …