Dr. Julio Viotti
Post-doctoral researcher
Scientific interests
The increase in the complexity of brains in evolution is accompanied by a surprisingly small number of new synaptic proteins, in particular when considering the remarkably wider range of behavioral responses a primate shows in comparison with a roundworm. However, a few vertebrate-specific synaptic proteins arose. These proteins may convey specialization and complexity to vertebrate nervous systems, for example by increasing vesicle reloading speed, and maintaining or eliminating a synapse. Vertebrate-specific proteins, together with more elaborate circuits, could bridge the gap between simple and complex behaviors. But intricate machineries lead to complicated maintenance and, as a result, malfunctions occur. One of these vertebrate-specific proteins, Synuclein, is involved in Parkinson’s disease. Another one, called Mover, is strongly upregulated in schizophrenia.
Mover is a synaptic vesicle-attached phosphoprotein, regulated by activity, and binds the conserved Calmodulin and the vertebrate-specific active zone protein Bassoon. Mover is differentially expressed at subsets of synapses.
I use a Mover knockout mouse line to investigate the role of Mover in the hippocampal mossy fiber to CA3 pyramidal cell synapse and Schaffer collateral to CA1 synapse. These experiments use extra- and intracellular electrophysiological recordings as well as several pharmacological tools and short- and long-term plasticity protocols to dissect the role of Mover in synaptic transmission.
Bio
- 10/2013 – 12/2018 Doctoral Degree in Neuroscience from University of Göttingen (Germany): International Max Planck Research School. Title of thesis: The presynaptic protein Mover buffers synaptic plasticity at the hippocampal mossy fiber synapse
- 10/2011 – 06/2013 Double Master’s Degree in Neuroscience from University of Göttingen (Germany) and University of Bordeaux (France). Title of thesis: Calmodulin/Munc13-1 Dependency in Vesicle Reloading at the Cerebellar Mossy Fiber Synapse
- 02/2006 – 12/2010 Bachelor’s Degree in Biology (emphasis in Health and Biotechnology) from Federal University of Minas Gerais (Brazil). Title of thesis: Electrophysiological Studies on the Color Vision on the Wulst of the Burrowing-Owl (Athene cunicularia)
Publications
- Quantifying the heterogeneous distribution of a synaptic protein in the mouse brain using immunofluorescence.
Wallrafen, R., Dresbach, T., Viotti, J. S.
J. Vis. Exp., in review, 2018 - Slowed vesicle recruitment upon increased calcium buffering does not prove calcium dependence of vesicle recruitment
Andreas Ritzau-Jost, Lukasz Jablonski, Julio Viotti, Noa Lipstein, Jens Eilers, and Stefan Hallermann
(under revision)