Dr. Daniel Johnston
Office: NMS 4.104
phone: (512) 232-6564
fax: 475-8000
email:
Daniel Johnston graduated cum laude from the University of Virginia in the field of Electrical Engineering and received his Ph.D. from Duke University (1974) in the fields of Biomedical Engineering and Physiology. He did his postdoctoral training in Cellular Neurophysiology at the University of Minnesota. Before moving to Austin he was appointed Professor of Neuroscience, Molecular Physiology, Biophysics, and Neurology at the Baylor College of Medicine. He also received the Grass Foundation Fellowship in Neurobiology at Woods Hole Marine Biological Laboratory. Currently he is the Karl S. Folkers Chair in Interdisciplinary Biomedical Research, Professor of Neurobiology, Director of the Center for Learning and Memory, and the Director of the Institute for Neuroscience at the University of Texas at Austin. He is also the Coordinator of the Neuroscience Institute, Marine Biological Laboratory at Woods Hole, and a Dart Foundation Scholar in Learning & Memory.
Research Interests
Research in the Johnston laboratory is primarily directed towards understanding the cellular and molecular mechanisms of learning and memory. We have focused our attention on neurons and synapses from the limbic system, mostly the hippocampus, subiculum, and entorhinal cortex. These areas are known to play important roles in learning and memory. Our research uses quantitative electrophysiological, molecular, optical imaging, and computer modeling techniques.
We are investigating the properties and mechanisms of long-term synaptic potentiation (LTP) and depression (LTD), synaptic substrates for aspects of memory. This interest has led us to investigate not only the basic mechanisms of synaptic transmission but also the principles of how synaptic inputs are integrated in the dendrites of the postsynaptic neuron. For example, we have recently used fluorescent imaging techniques and dendritic patch-clamp recordings to identify the types and location of voltage-gated Na+, Ca2+, K+ and h-channels in dendrites of hippocampal pyramidal neurons. Furthermore, we have found that many of these channels undergo activity-dependent changes in their properties during LTP and LTD. These changes result in long-term alterations in neuronal excitability. This work is complemented by our computer modeling studies in which we attempt to reconstruct the biophysical properties of hippocampal neurons based on our experimental data. We hope that these investigations will enhance our understanding of the cellular and synaptic mechanisms of learning and memory and provide insights into the function of the limbic system in the behaving animal.