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Acta Physiologica 2012; Volume 204, Supplement 689
91st Annual Meeting of The German Physiological Society
3/22/2012-3/25/2012
Dresden, Germany
NANODOMAIN COUPLING AT THE GLUTAMATERGIC PARALLEL FIBER TO PURKINJE CELL SYNAPSE
Abstract number: O80
Schmidt1 *H., Brachtendorf1 S., Arendt1 O., Hallermann2 S., Schaarschmidt1 G., Heckmann3 M., Eilers1 J.
1Carl-Ludwig-Institute for Physiology II, Leipzig, Germany
2European Neuroscience Institute, Gttingen, Germany
3Institute for Physiology, Neurophysiology, Wrzburg, Germany
A key factor determining speed and fidelity of central nervous system processing is the coupling distance between the site of Ca2+ influx and the sensor for vesicular transmitter release (1–3). Although tight, nanodomain coupling improves speed and reliability of neurotransmission, excitatory CNS synapses are typically considered to operate at loose, microdomain influx-release coupling (4–6). An exception to this view is the idea that coupling tightness increases at the Calyx of Held during maturation (7). We hypothesized that typical excitatory cortical synapses processing high-frequency coded information require tighter than microdomain coupling. We tested this hypothesis at mature parallel fiber to Purkinje cell synapses, the most abundant CNS synapses, of wild-type and calretinin deficient mice. Combining multiple-probability fluctuation analyses from paired electrophysiological recordings, presynaptic Ca2+ imaging and non-steady-state computer simulations we provide evidence that parallel fiber terminals harbor active zones with nanodomain influx-release coupling (~25 nm), much tighter than any other excitatory cortical synapse investigated to date.
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Supported by DFG grants to JE and HS (El 342/4-1), to SH (HA 6386/2-1), and to MH (HE 2621/4-2 and TP B27/SFB 581).
To cite this abstract, please use the following information:
Acta Physiologica 2012; Volume 204, Supplement 689 :O80