Stephen T. Kitai
Steve Kitai spent his childhood in the industrial city of Osaka in wartime Japan. He came to the United States after the end of World War II and attended junior high and high school in the Detroit area. He attended the University of Michigan, where he majored in Psychology. As an undergraduate, Steve worked in the laboratory of Russell De Valois, who was at that time just beginning his now classic studies of color vision. In De Valois' lab, he learned neurophysiology by recording single unit responses in monkey lateral geniculate nucleus and was a coauthor on three fundamental papers that began the study of color sensitivity of thalamic cell responses. While participating in these experiments, Steve discovered that he was colorblind, so for his doctoral training he switched to the somatosensory system. He received his PhD in 1964 from nearby Wayne State University under the direction of Ferdinando Morin of the Department of Anatomy. There he studied the dorsal spinocerebellar tract and the lateral cervical nucleus, but also worked on brain mechanisms of classical conditioning, which formed the basis for his PhD dissertation.
Morin died in 1964, only a short time after Steve defended his PhD thesis. Morin's lab was supported by an NIH grant from the National Institute of Neurological Diseases and Blindness (the predecessor of today's Institute of Neurological Disorders and Stroke). The NINDB was founded in 1950 and Morin's grant was one of the first awarded, in 1954. When Morin died, there were still two years left on the grant, and Clement Fox, the new chairman of the Department of Anatomy, asked Steve to stay on as an Assistant Professor to continue Morin's research program (and his NIH grant). This required a delay in Steve's plans for postdoctoral training in cerebellar neurophysiology. Steve agreed, and Fox helped arrange a prestigious postdoctoral stint with John Eccles in Eccles' new laboratory in Chicago while maintaining his position at Wayne State. The grant was transferred to Steve in its 12th year in 1964. Steve received a no-cost extension to do his studies with Eccles from 1966 to 1968 and returned to Wayne State with a promotion to Associate Professor. He would keep this historic NIH grant, entitled "Experimental Studies of Sensory Pathways", through a series of competing renewals and a variety of other grants, until his retirement in 2002. Steve had a deep respect for Fox and stayed in the Department of Anatomy at Wayne State for 15 years, leaving only after Fox stood down as Chair of the Department.
Steve's years (1966-1968) in the labs of John Eccles and Rodolfo Llinás at the Institute for Biomedical Research of the American Medical Association in Chicago spanned most of the institute’s brief history at that location. This period loomed large in Steve's memory, and he entertained his own students with many stories of his experiences there. Like all of Steve's stories, these were funny, but contained a career lesson for the attentive listener. With Rodolfo Llinás and Wolfgang Precht, he worked on vestibular input to the cerebellar cortex. With John Eccles and Nakaakira Tsukahara, his work was on somatosensory inputs to the cerebellar cortex and cerebro-cerebellar connections. His collaboration with Tsukahara continued after the Chicago years, and Steve took a visiting professorship at Tokyo University to collaborate with Tsukahara in 1970.
Upon returning to Wayne State in 1968, Steve focused on applying intracellular recording to reveal the connectivity and synaptic sign of connections in a wide variety of brain regions, including the hippocampus, facial nucleus, lateral reticular nucleus, inferior olive, and deep cerebellar nuclei. He was promoted to Professor in the Department of Anatomy at Wayne State in 1972.
In 1973-74 he was a visiting scholar at the Max-Planck Institut für Hirnforschung, where he again worked with Precht, this time on the synaptic connections between the substantia nigra and caudate nucleus. This began Steve's long association with the basal ganglia. One of the central issues in that collaboration was an attempt to identify the synaptic potentials evoked in caudate neurons by stimulation of the dopaminergic cells of the substantia nigra. In the years that followed, Steve gradually turned his entire laboratory over to the study of basal ganglia neurons and circuits using intracellular recording. The lab developed and applied the new technique of intracellular labelling with horseradish peroxidase for morphological cell identification in intracellular recording, and applied this powerful in vivo approach to the study of neuronal circuitry. Steve left Wayne State to take the chair of Anatomy at Michigan State University in 1978, where he continued his basal ganglia studies. Steve's lab published 13 papers between 1976 and 1979 on the topic of striatal neuron synaptic responses and nigrostriatal synaptic relations. The action of dopamine was a topic of intense controversy during those years and Steve was convinced his intracellular recording technique was superior to the extracellular approaches taken by his rivals. Intracellular recording could reveal subthreshold synaptic potentials, and so could reveal the sign of synaptic effects even in neurons that were not firing. The controversy surrounding dopamine raised Steve's profile in the field. He thrived on the role of brash outsider in a field dominated by catecholamine royalty who were aligned against him.
Steve left Michigan State to take the chair of the Department of Anatomy at the University of Tennessee Health Sciences Center (UTHSC) at Memphis in 1983. He quickly built up a strong research group and made the department into a major Neuroscience research and training center. He also became the first Director of the Tennessee Higher Education’s Neuroscience Center of Excellence (1985), which remains today. He remained at UTHSC until his retirement in 2002.
Much of what is foundational knowledge today about the basal ganglia came from Steve and his laboratory. Steve's goal was to identify the cell types that make up each nucleus in the basal ganglia and their synaptic targets, and determine their neurotransmitters and the sign of their synaptic effects. He provided the conclusive demonstration that spiny neurons are the projection cells of the striatum. He showed that there are two kinds of spiny projection neurons, one whose axonal target was the external globus pallidus and one whose targets included the substantia nigra. He demonstrated the excitatory nature of the cortical input on spiny neurons, and showed that thalamic and cortical inputs converge onto individual spiny neurons. He established the excitatory nature of the subthalamo-pallidal and the cortico-subthalamic pathways, and the inhibitory effect of globus pallidus on subthalamic neurons. Steve's lab also provided the beginnings for our understanding of cell-type specific physiological properties of basal ganglia cells, describing the electrotonic and spike generating properties of cells in the striatum, globus pallidus, subthalamic nucleus, substantia nigra and pedunculopontine nucleus. His later work progressed with modern techniques to study ionic currents and their transmitter modulation using slice, slice cultures or dissociated cells combined with patch clamp and molecular genetic tools.
Steve trained 14 successful PhD students and about 60 postdocs and visiting scientists, many of whom continue to work on the basal ganglia. He was a founding member of the International Basal Ganglia Society and the Spring Brain Conference. He was president of the Association for Neuroscience Departments and Programs and the Cajal Club. He served on the Membership and Finance committees of the Society for Neuroscience, and for 6 years was treasurer of the International Basal Ganglia Society. He received one of the first Jacob Javits awards from the National Institute of Disease and Stroke. Steve directed a collaborative basal ganglia program project grant from 1988 to 2003. He also maintained international collaborations through a Human Frontier Science Program grant from 1991-1994.
Steve was audacious and rebellious, sometimes to the point of recklessness. He believed in the value of controversy as a motivator in research and in all human affairs, and he fostered it within his laboratory. Above all, he always seemed to be having fun, and everyone else seemed to be taking things too seriously.