Dendritic coincidence detection in Purkinje neurons of awake mice

• Published in: eLife Vol. 9
• Main Authors: Roome, Christopher J, Kuhn, Bernd
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 21.12.2020; eLife Sciences Publications, Ltd; eLife Sciences Publications Ltd
• Subjects: Animals; awake; Calcium - metabolism; Calcium channels; Calcium Channels - metabolism; cerebellum; dendrites; Dendrites - physiology; Glutamate; Male; Mice; Mice, Inbred C57BL; Neurons; Neuroscience; Purkinje Cells - physiology; Purkinje neuron; Synapses - physiology; two-photon microscopy; voltage imaging; Wakefulness - physiology; mouse; voltage imaging; neuroscience; Purkinje neuron; dendrites; two-photon microscopy; awake; cerebellum
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.59619

Dendritic coincidence detection is fundamental to neuronal processing yet remains largely unexplored in awake animals. Specifically, the underlying dendritic voltage-calcium relationship has not been directly addressed. Here, using simultaneous voltage and calcium two-photon imaging of Purkinje neuron spiny dendrites, we show how coincident synaptic inputs and resulting dendritic spikes modulate dendritic calcium signaling during sensory stimulation in awake mice. Sensory stimulation increased the rate of postsynaptic potentials and dendritic calcium spikes evoked by climbing fiber and parallel fiber synaptic input. These inputs are integrated in a time-dependent and nonlinear fashion to enhance the sensory-evoked dendritic calcium signal. Intrinsic supralinear dendritic mechanisms, including voltage-gated calcium channels and metabotropic glutamate receptors, are recruited cooperatively to expand the dynamic range of sensory-evoked dendritic calcium signals. This establishes how dendrites can use multiple interplaying mechanisms to perform coincidence detection, as a fundamental and ongoing feature of dendritic integration in behaving animals.