Editors Note: Ocassionally Pathways will offer an historical account of someone who has made outstanding contributions to our field of neuroaudiology who is not an audiologist. Clinton Woolsey is one of those people he was a renounded neuroanatomist/neurophysiologist . Here is a nice review by Kylie Boyd.
Kylie Boyd, B.S., B.A.
Au.D. Student, University of Arizona, Dept. of Speech, Language and Hearing Sciences
The work of Dr. Clinton Woolsey was fundamental in laying the foundation of modern neuroanatomy. Throughout his life, Dr. Woolsey discovered features of the mammalian brain that challenged the way that the brain was thought of at the time. Even today, neuroanatomists continue to build off his ideas and discoveries. Woolsey’s work on the central auditory system has become ever important to both basic and clinical researchers interesting in the neurobiology of hearing.
Clinton Nathan Woolsey was born on November 30, 1904, to Joseph Woodhull & Mathilda Louise Aicholz Woolsey. He grew up in New York and attended multiple high schools. In his junior year, Woolsey was awarded the H. Bernard Gold Medal as the best student of the year. Dr. Walter Allan Cowell attended the award ceremony where Woolsey was receiving his award and took an immediate interest in him. Dr. Cowell was studying the effect of insulin on diabetes, which had just been discovered. Because of his association with Dr. Cowell, Woolsey became greatly interested in medicine and in research. (Thompson, 1999).
Woolsey graduated at the top of his high school class and attended Union College in Schenectady, New York, in 1925. Upon graduating, he was initially interested in becoming a neurosurgeon and attended Johns Hopkins University School of Medicine to do so. One of the courses that Woolsey took at Johns Hopkins focused on the localization of function, which was taught by Dr. Marion Hines, an experimental anatomist, and Dr. Sarah Tower, who was a successful animal neurosurgeon (Thompson, 1999). Woolsey worked with Dr. Sarah Tower in her neuroanatomy lab for a year before Dr. Hines invited Woolsey to work with her on the cortical localization of the dog brain. This led to Woolsey’s first publication in 1933: “On the Postural Relations of the Frontal and Motor Cortex of the Dog” (Lyon et al., 2014).
Unfortunately, before finishing his fourth year of school at Johns Hopkins, Woolsey developed pulmonary tuberculosis, which was fairly common in medical students. Woolsey had to leave school for six months to recuperate. Upon recovery, Woolsey was advised that working as an intern in surgery may be too physically demanding and could cause damage to his pulmonary lesion (Thompson, 1999).
However, after healing from tuberculosis, Philip Bard, of the Cannon-Bard Theory, invited Woolsey to work with him in his lab. Bard’s previous work suggested that the occurrence of emotions relies on the thalamus sending a message to the brain in response to a stimulus. This, in turn, results in a physiological reaction (Cherry, 2019). Working with Dr. Bard helped Clinton Woolsey come to the realization that his future was in neuroanatomy (Lyon et al., 2014).
Bard and Woolsey’s early experiments, during the 1930s and 40s, focused primarily on the cerebral cortex, the part of the brain most involved in advanced functions such as sensory perception. During this period, the most known way to measure function was to create a lesion in the brain and observe which area lost function. However, this did not provide any solid, finite data and caused permanent damage to the brains that they were studying (Lyon et al., 2014).
Contemporaneous to the work of Bard and Woolsey, Wade Marshall and Ralph Gerard from the University of Chicago were exploring using electrodes to study electrical potentials in the brains of cats. Dr. Marshall moved from Chicago to Johns Hopkins Physiology department and brought the equipment needed to set up an electrophysiology lab (Lyon et al., 2014). Woolsey was attracted to the use of electrophysiology and discovered that this equipment could be used to create cortical potentials and map cortical representations of the body regions. This method preserved the brain by avoiding lesions or overstimulation. Therefore, more accurate functional brain mapping could be achieved (Lyon et al., 2014).
Building from this, previously, neuroscientists assumed that the sensory cortex, the auditory cortex, and the visual cortex only had one pathway to each. In 1940, a physiologist named Lord Edgar Adrian discovered a secondary sensory cortical area in cats after stimulating the hairs between a cat’s claws using electrical potentials. However, he was unable to identify this region in other species and concluded that this feature must be unique to cats (Lyon et al., 2014). During this time, Woolsey had explored and mapped the cortices of many other mammals, including humans. Based on Dr. Adrian’s research, he was able to discover secondary cortical regions in species other than cats and even found secondary regions for visual and auditory inputs as well. In an interview, Woolsey stated, “all of a sudden, within a period of about a year, somatosensory, visual, and auditory systems all had two areas in the cortex instead of just one” (Lyon et al., 2014).
In 1947, Dr. Woolsey was invited to give a lecture in Montreal, where he met Dr. Wilder Penfield. During one of his lectures, Woolsey described how he had discovered another somatosensory area on the “upper bank of the Sylvian Fissure” in monkeys (Lyon et al., 2014). Penfield was fascinated by this and built off Woolsey’s research to confirm such an area. Their combined research was later used to diagnose epileptic foci in this area that was previously overlooked due to poor understanding of the function (Lyon et al., 2014). This in turn lead the way to advances in auditory cortex mapping.
Dr. Woolsey made another crucial discovery in 1942, when he worked with Dr. Edward Walzl to explore the tonotopic organization of the auditory cortex. At the time, it was known that regions of the cochlea responded to different frequencies of sound, but not much was known about how the auditory cortex did so. For their study, Woolsey and Walzl stimulated localized regions of auditory nerve fibers in the cochleae of cats and monkeys (Woolsey, 1982). Using this information, they mapped the patterns of the evoked responses on the auditory cortex. This was important because it was the first clear demonstration of the tonotopic organization of the auditory cortex. After this experiment, Dr. Woolsey and Dr. Walzl continued on to examine the effects of cochlear lesions on click responses in the auditory cortex, which lead to an even greater understanding of the auditory cortex (Woolsey, 1982).
Woolsey then worked with Dr. Jerzy Rose to complete “detailed lesion-retrograde degeneration mapping of the projections from the auditory region of the thalamus (medial geniculate body) to the auditory cortex” (Thompson, 1999). This was founded upon the work that he and Walzl had defined earlier. The pair also completed similar studies “on the projections of the mediodorsal nucleus to the orbitofrontal cortex (1947) and on the relations between the anterior thalamic nuclei and the limbic cortex (1948)” (Rose & Clinton, 1949).
Dr. Jerzy Rose moved to Madison, Wisconsin in 1958 to continue working with Dr. Woolsey, and brought an extracellular microelectrode that he had helped develop. Having this technology, Woolsey was able to create cortical maps in even more detail, as this equipment allowed a hundred-fold amplification in cortical mapping experiments. This technology also served as a foundation for “modern clinical neurophysiological monitoring” (Lyon et al., 2014). Woolsey examined the sensory, motor, and auditory cortices of a wide range of species using this method throughout the 1950s and beyond (Lyon et al., 2014).
It was in 1948, when Woolsey accepted an appointment as Charles Sumner Slichter Professor Emeritus of Neurophysiology at the University of Wisconsin Medical and Graduate Schools in Madison. He remained at Wisconsin for the rest of his career until he retired in 1975, and eventually passed away in 1993 (Thompson, 1999). Clinton Woolsey has had a lasting impact on the neuroanatomy community, and his work continues to remain the foundation for many experiments exploring and attempting to understand the complexities of the human brain.
References
- Cherry, K. Understanding the Cannon-Bard Theory of Emotions. Verywell Mind. (2019). Retrieved from https://www.verywellmind.com/what-is-the-cannon-bard-theory-2794965
- Lyon, W., Mehta, T. I., Pointer, K. B., Walden, D., Elmayan, A., Swanson, K. I., & Kuo, J. S. (2014). Clinton Woolsey: functional brain mapping pioneer. Journal of neurosurgery, 121(4), 983–988. doi:10.3171/2014.6.JNS132030
- Rose, J., Woolsey, C. (1949). The Relations of Thalamic Connections, Cellular Structure, and Evocable Electrical Activity in the Auditory Region of the Cat. The Wistar Institute of Anatomy and Biology. (441-465)
- Thompson, R. (1999). Clinton Nathan Woolsey: A Biographical Memoir. National Academy of Sciences. (3-13).
- Woolsey, C. (1982). Multiple Auditory Areas. Cortical Sensory Organization. (235-241).
