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Henrique von Gersdorff earned a Ph.D. in Physics from the University of Minnesota in 1989 and a Ph.D. in Neurobiology from the State University of New York at Stony Brook in 1995. He received his B.S. in Physics from the Federal University of Rio de Janeiro. He was a guest scientist in high-energy physics at the Fermi National Laboratory and at the Brookhaven National Laboratory. Von Gersdorff did his postdoctoral fellowship at the Max-Planck Institute for Biophysical Chemistry, Department of Membrane Biophysics. In 1998, he was appointed as an assistant scientist in the Vollum Institute and was promoted to scientist in 2004. He also holds an associate professorship in the Cell and Developmental Biology department at OHSU.
Research Interests
Sensory information is conveyed by neurons specialized to faithfully transmit large amounts of information at high rates. A key event in synaptic transmission is the release of neurotransmitter via vesicle fusion at synaptic terminals. Direct studies of synaptic terminals have been hampered by technical constraints. However, using high time resolution patch-clamp and membrane capacitance measurements, von Gersdorff and his associates have studied the kinetics of vesicle fusion (exocytosis) and subsequent membrane retrieval (endocytosis) in single, live synaptic terminals from bipolar cells of the goldfish retina. These giant terminals have compact ribbon-type active zones that contain a large pool of releasable vesicles suitable for the transfer of high bandwidths of information. Following short depolarizations, a fast form of endocytosis can be observed, indicating that synaptic vesicle membrane is quickly re-internalized after vesicle fusion. Von Gersdorff and his colleagues are presently investigating glutamate reuptake and short-term synaptic plasticity at reciprocal synapses in retinal slices. They have found that exocytosis releases not only neurotransmitters but also protons that acidify the synaptic cleft and inhibit presynaptic Ca2+ currents, thus changing paired-pulse depression.
To study conventional active zone synapses, the lab has also been examining the calyx of Held, a pivotal element in the auditory brainstem circuitry that computes sound source localization. Precise timing of action potential discharges is essential for accomplishing this task. Nevertheless, the mechanisms that modulate and preserve the timing of spikes are poorly understood. Von Gersdorff and his coworkers are studying these mechanisms and short-term forms of plasticity at this synapse. The large size of the calyx terminal allows them to patch-clamp the terminal and the postsynaptic cell simultaneously, and thus to measure presynaptic capacitance changes, Ca2+ currents, and glutamate release. This direct access to the terminal allows the lab to study the kinetics of synaptic vesicle exocytosis and recycling, neurotransmitter reuptake, and the modulation of neuronal output patterns by presynaptic receptors. Presently, the lab is focused on presynaptic cannabinoid and metabotropic glutamate receptors and on developmental changes that fine-tune the synapse for high frequency firing.
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Selected Publications
Hull, C. and von Gersdorff, H. (2004) Fast endocytosis is inhibited by GABA mediated chloride influx at a presynaptic terminal. Neuron 44:469-482.
Kushmerick, C., Price, G., Taschenberger, H., Puente, N., Renden, R., Wadiche, J., Duvoisin, R., Grandes, P., and von Gersdorff, H. (2004) Retroinhibition of presynaptic Ca2+ currents by endocannabinoids released via postsynaptic mGluR activation at a calyx synapse. J. Neurosci. 24:5955-5965.
Palmer, M.J., Hull, C., Vigh, J., and von Gersdorff, H. (2003) Synaptic cleft acidification and modulation of short-term depression by exocytosed protons in retinal bipolar cells. J. Neurosci. 23:11332-11341.
Palmer, M.J., Taschenberger, H., Hull, C., Tremere, L., and von Gersdorff, H. (2003) Synaptic activation of presynaptic glutamate transporters in nerve terminals. J. Neurosci. 23:4831-4841.
Taschenberger, H., Lećo, R., Rowland, K., Spirou, G., and von Gersdorff, H. (2002) Optimizing synaptic architecture and efficiency for high frequency transmission. Neuron 36:1127-1143.
Lećo, R. and von Gersdorff, H. (2002) Noradrenaline increases high-frequency firing of the calyx of Held synapse during development by inhibiting glutamate release. J. Neurophysiol. 87:2297-2306.
von Gersdorff, H. and Borst, J.G.G. (2002) Short-term plasticity at the calyx of Held. Nature Rev. Neurosci. 3:53-64.
von Gersdorff, H. (2001) Synaptic ribbons: versatile signal transducers. Neuron 29:7-10.
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