Calbindin in cerebellar Purkinje cells is a critical determinant of the precision of motor coordination - PubMed (original) (raw)

Synaptic Ca2+ signaling.A, Top, Line scan recording of early synaptic calcium transients evoked by single parallel fiber stimulation (ESCT) in a spine and the adjacent dendrite of a not-recombined mouse. Left, Image of the spiny dendrite and the line and regions of interest chosen for the experiment. Scale bar, 1 μm; d, dendrite; s, spine. Below, Current (EPSC) evoked by parallel fiber stimulation (stimulation intensity, 30 V). Right, ESCT in the spine and the dendrite. Broken red lines represent monoexponential decay functions fitted to the data points. Time constants (τ) were 348 msec (spine) and 363 msec (dendrite). Bottom, ESCT in a spine and the adjacent dendrite of a recombined mouse. Left (compare with top), Stimulation intensity was 10 V. Right, Despite the smaller EPSC amplitude, ESCT amplitudes were much larger than in the not-recombined animal. Time constants were significantly faster. B, Top, Line scan recording of early synaptic calcium transients evoked by climbing fiber stimulation in a spine and the adjacent dendrite of a not recombined mouse. Left (compare with A, below), Complex spike evoked by climbing fiber stimulation. Right, Calcium transients in the spine and the dendrite and time constants calculated from monoexponential decay functions (compare with A). Bottom, Calcium transients in a spine and the adjacent dendrite of a recombined mouse. Right, Despite the similar electrical response, amplitudes of calcium transients were much larger than in not recombined animal. Time constants were significantly faster. Calcium transients represent the averages of three consecutive trials; arrowhead indicates the time of synaptic stimulation. C, Histograms of ESCT amplitudes and decay time constants in spines (s) and dendrites (d) of not-recombined and recombined animals (parallel fiber stimulation: black bars, n = 21 dendrites, 30 spines; gray bars,n = 17 dendrites, 44 spines; climbing fiber stimulation: black bars, n = 11 dendrites, 26 spines; gray bars, n = 18 dendrites, 35 spines;). Error bars represent SEM. D, mGluR-mediated synaptic calcium signaling. Right, Local dendritic Ca2+signals mediated by repetitive parallel fiber stimulation (marked by arrowheads, 5 pulses, 50 Hz) in the presence of 40 μ

m

CNQX. Images demonstrate activated dendritic regions. Scale bars, 20 μm. Traces show relative changes in fluorescence in regions of interest within these active regions. Broken red lines represent monoexponential decay functions fitted to the data points. Time constants were 806 msec (not recombined) and 811 msec (recombined). Below, Histogram of dendritic decay time constants of the delayed synaptic calcium transients evoked by repetitive parallel fiber stimulation (DSCT) [n = 5 for not recombined;n = 7 for recombined; averages are not significantly different (t test, p< 0.01)]. Error bars represent SEM.