Committee on the Conceptual Foundations of Science, University of Chicago
Neuroscience is the integrated study of the anatomy, behavior, and physiology of the nervous system. By this definition it has been common for only a few decades, however, there were a few earlier research programs that resembled modern neuroscience - Lorente de Nó's is one. My talk reviews the development of his approach. In 1921, Lorente became Ramón y Cajal's student - Cajal's last student. Lorente's Golgi studies of the cortex and brainstem led him to question Cajal's belief that direct neural pathways cause most behavior. Lorente saw that indirect pathways are crucial. To show this he lesioned the cerebellum and showed that reflexes whose direct pathways include it, recovered. He attributed their recovery to the indirect pathways. Lorente next studied nystagmus eye movements. His first experiment showed that lesioning the indirect pathways eliminated the fast nystagmus reflex. In 1924, Lorente began post-doctoral work with Bárány. During this period, Lorente made detailed studies of the normal vestibular-ocular reflexes, the effects of lesions on them and the anatomy of neurons in the brainstem. In reaction to Sherrington's school, whose work he studied carefully, Lorente emphasized that reflexes are the result of integration by central neuroses. In 1927, while visiting the Vogt's institute, Lorente began studying the neurons and cytoarchitectonics of the limbic cortex. Around 1930, he began constructing circuit diagrams to explain the effects of lesions in terms of the underlying anatomy. After moving to America in 1931, Lorente begun discussing the general principles shown in his circuit diagrams. In his studies on the anatomy of the cochlear nuclei and limbic cortex, he applied his general principles to the interactions of individual neurons. In 1934, Lorente began electrophysiological experiments to record the synaptic delay, refractory period and affects of antidromic activation on ocular motorneurons. In studies of facilitation and inhibition he showed how interneuron circuits could explain his findings. With Graham, Lorente began studying the properties of nerves. In the late 1930s, after producing a series of reviews summarising his findings and principles, Lorente began to record field potentials in the ocular motor system with microelectrodes. To interpret his results he developed a mathematical treatment of volume conduction and extended his studies of nerve properties. Examining Lorente's work shows the extent to which neuroscience was possible in the 1920s and 1930s.
Saturday, 21 June 1997, 8.50 - 9.05
Second Annual Meeting of the International Society for the History of the Neurosciences (ISHN) and 6th Meeting of the European Club on the History of Neurology (ECHN)
Leiden, The Netherlands