The Journal of Neuroscience, 2001, 21:RC158:1-4
RAPID COMMUNICATION
Spatial Distribution of Low- and High-Voltage-Activated Calcium
Currents in Neurons of the Deep Cerebellar Nuclei
Volker
Gauck2,
Michael
Thomann1,
Dieter
Jaeger2, and
Alexander
Borst1
1 Friedrich-Miescher-Laboratory of the
Max-Planck-Society, 72076 Tuebingen, Germany, and
2 Department of Biology, Emory University, Atlanta, Georgia
30322
The spatial distribution of low-voltage-activated (LVA) and
high-voltage-activated (HVA) barium currents was investigated in
neurons of the deep cerebellar nuclei (DCN) by combining barium imaging
with voltage clamp. The current-induced fluorescence signal (
F/F) of the HVA current was five
times higher then the LVA-induced signal at the soma, but both signals
were approximately equal in size in distant dendrites. This
position-dependent shift of
F/F
indicates a non-uniform distribution of the underlying calcium channels. The higher weight of the LVA signal in the dendrites suggests
that the LVA might be of particular relevance for the dendritic
integration of synaptic inputs.
Key words:
calcium imaging; low-voltage-activated calcium current; high-voltage-activated calcium current; dendritic integration; subcellular compartmentalization; cerebellar nuclei
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