VSD allows to measure membrane potential variations at a network level.
The voltage sensitive dye (VSD) is a molecule that, once bound to the external surface of cell membranes, acts as a molecular transducer transforming changes in membrane potential into optical signals (changes in absorption or emitted fluorescence). The amplitude of VSD signals are directly correlated with changes in membrane potential.
The VSD (Di-4Anepps; Molecular Probes) signals coming from acute cerebellar slices are collected with a fast CCD camera (up to 1.5 KhZ sampling frequency; Scimedia).
We use VSD imaging to follow the propagation of excitation and inhibition into the granular and molecular layers after the stimulation of the mossy fiber bundle. The complex dynamics of these events could be described with a spatial resolution that other electrophysiology techniques don’t allow.
Example of single pulse in the white matter (mf=mossy fibers; ML=Molecular Layer; GL=Granular Layer)
Jonathan Mapelli, Daniela Gandolﬁ and Egidio D’Angelo. (2010). High-pass ﬁltering and dynamic gain regulation enhance vertical bursts transmission along the mossy ﬁber pathway of cerebellum. Frontiers in Cellular Neuroscience. 2010 May 28;4:14.
- Jonathan Mapelli, Daniela Gandolﬁ, and Egidio D’Angelo. (2010) Combinatorial Responses Controlled by Synaptic Inhibition in the Cerebellum Granular Layer. J Neurophysiol 103: 250 – 261.
- F. Prestori, C. Bonardi, L. Mapelli, P. Lombardo, R. Goselink, M. Egle De Stefano, D. Gandolfi, J. Mapelli, D. Bertrand, M. Schonewille, C. De Zeeuw, E. D’Angelo. Gating of Long-Term Potentiation by Nicotinic Acetylcholine Receptors at the Cerebellum Input Stage. Plos One. May 2013 – Volume 8 – Issue 5 – e64828.