Simons Institute for the Theory of Computing - Active Dendrites … · 2020. 1. 3. · Jim Heys...
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Active Dendrites Contribute to Hippocampal Place Field Formation Mark Sheffield, Department of Neurobiology, The University of Chicago
Transcript of Simons Institute for the Theory of Computing - Active Dendrites … · 2020. 1. 3. · Jim Heys...
Active Dendrites Contribute to Hippocampal Place Field FormationMark Sheffield, Department of Neurobiology, The University of Chicago
2 m linear VR track CA1 somatic population imaging
Co-acquired CA1 somatic and basal dendritic imaging
Switching the Virtual Environment Causes Remapping of the Hippocampal Cognitive Map
Cel
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Cel
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Track Position Track Position
Mean place field position Mean place field position
Linear track 1 Linear track 2
Virtual teleportation
78 Place cells covering linear track 1
Example cell: delayed place field
Lap
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Track Position (cm)1 300
Delay
Example cell: Instant place field
The majority of place fields appear within the first ~15 laps of exposure to a novel environment
Sheffield et. al., Neuron, 2017
Soma & all branches Soma & no branches
Place field transient 1 Place field transient 2(same cell)
Branch spiking throughout the arbor can vary between place field traversals
Sheffield et. al., Neuron, 2017
Branch spike prevalence across basal dendrites is highest when place fields first appear
Branch spike prevalence predicts future place field location
Branch spiking
First few laps in novel environment
Somatic place field
High Low Low
Many laps in novelenvironment
Avg
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sp
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pre
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Sheffield et. al., Neuron, 2017
In-vivo spontaneous dSpike
Ex-vivo evoked dSpike
10 um
Localized dendritic branch spikes in CA1 basal dendrites
7 spines0.5 ms laser duration0.12 ms interstim interval<0.5 ms to stimulate them all
dSpikes occur prior to the formation of delayed place fields
Rest Spine transient Branch spike Dendritic spike
Matched image settings
10 um
Example cell: delayed place field
Lap
nu
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Track Position (cm)1 300
Sheffield et. al., Neuron, 2017
Ethan Goldberg & Douglas Coulter (2013)
Interneurons that target CA1 dendrites could regulate dendritic spikes
SOM+ Interneurons
Axons in CA1 basal dendritic layer
20 μm
Sheffield et. al., Neuron, 2017
Dendritic inhibition is transiently reduced during novel environment exposure
Sheffield et. al., Neuron, 2017
Localized dendritic spikes absent during place field Formation in NR1KO
Inducible knock out of NMDA receptors in CA1 neurons disrupts active dendritic signals
Branch spikes reduced during place field formation in NR1KO
WT mice
Sheffield et. al., Neuron, 2017
NMDA KO in CA1 neurons decreases the number of place fields that form
Sheffield et. al., Neuron, 2017
Sheffield et. al., Neuron, 2017
Acknowledgements
Dombeck Lab:
Mark Howe
Jim Heys
Mike Adoff
Brad Randall
Jason Climer
Funding:
NSF 1516235NIH 1R01MH101297
Acknowledgements
Sheffield Lab:
Can Dong (Grad student)
Chery Cherian (Tech)
Jo DiPietro (Post Doc)
Madeline Klinger (Tech)
Funding:
UChicago Start up
Whitehall Foundation
Sloan Fellowship
