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Multiscale and multimodal reconstruction of cortical structure and function

Nick Turner & “Tony” Runzhe Yang

11-5-2020

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Zebrafish hindbrain

Vishwanathan et al., bioRxiv, 2020

Mouse S1

Motta et al., 2019

Full adult drosophila brain

Dorkenwald et al., bioRxiv, 2020

Zebrafinch area X

Kornfeld et al., bioRxiv, 2020

Drosophila hemibrain

Scheffer et al., 2020

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Zebrafish hindbrain

Vishwanathan et al., bioRxiv, 2020

Mouse V1

Lee et al., 2016

Mouse retina

Bae et al., 2018

Zebrafish olfactory bulb

Wanner et al., 2020

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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250 x 140 x 90 µm3

TEM Volume

Mouse V1 Layer 2/3

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Dorkenwald et al., bioRxiv, 2019

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363 (/416)

Pyramidal cells

34 Inhibitory cells

169 non-neuronal cells

↑ have proofread morphology

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> 3 million synapse

predictions

~85% prec & rec overall

Synapses between 363 PyCs were proofread

Accurate graph of

1981 synapses in

1752 connections

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Dorkenwald et al., bioRxiv, 2019

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Over 96,000 orphans possess at least 10 predicted synapses,

where each orphan’s synapses are uniformly presynaptic or postsynaptic

7% merge error rate

(out of 200)

“Orphans”

Cells w/ soma

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Automated mitochondria segmentation

93.6% precision

92.7% recall

Qualitatively, ~10%

dendritic mitos split,

some “weak” output in somas

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Zhou et al., bioRxiv, 2020

2-Photon calcium imaging for

112 Pyramidal cells

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16 directions

(pseudorandomized)

30 “trials”

~ 30 minutes

recording

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Automated segmentation (w/ some proofreading)

Automated synapses (w/ some proofreading)

Automated mitochondria

Functional data

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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Pyramidal Cell Subgraph

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  • 113 neurons w/ >100 μm axons.

  • “Less truncated neurons” are mainly concentrated at small y (shallow in depth) area.

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Pyramidal Cell Subgraph

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  • 762 synapses among this subset of PyCs.

  • A directed simple graph consisting of 113 nodes and 666 edges.

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Null Model: Erdős-Rényi Graphs

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  • Directed edges are drawn independently with the same probability.

  • The expected number of edges matches the observation.

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Degree Sequences

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  • In-degree = # presynaptic pyramidal cells in the graph.

  • The observed degree distribution is “wider” (has larger variance) than the expected degree distribution of the ER model.

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Degree Sequences

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  • Out-degree = # postsynaptic pyramidal cells in the graph.

  • The observed degree distribution is “wider” (has larger variance) than the expected degree distribution of the ER model.

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Two-Cell Motifs

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5,691

608

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Null Model: Configuration Model

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  • The “simplest” random model which preserves degree sequences.

  • A switch-and-hold algorithm samples graphs with same degree sequences uniformly (unbiased motif counts).

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Two-Cell Motifs Frequencies

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  • The overrepresentation of bi-directional connections is significant with respect to both ER and CFG.

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Two-Cell Motifs Frequencies

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  • The overrepresentation of bi-directional connections is roughly consistent with Song et. al. 2005

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Three-Cell Motifs

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171,860

51,793

2,531

2,436

1,521

2,891

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358

12

355

75

16

23

8

2

0

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Null Model: Generalized ER Model

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  • Edges are drawn independently at random for all pairs of nodes (e.g., A and B):

    • A→B w/ probability puni
    • A←B w/ probability puni
    • AB w/ probability pbi
    • A B w/ probability(1-2puni-pbi )

  • The expected number of both uni-directional and bi-directional edges matches the observation.

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Three-Cell Motifs Frequencies

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  • The overrepresention of motifs 4, 10, 11, 12 is significant w.r.t. generalized ER.

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Three-Cell Motifs Frequencies

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  • The overrepresentation of motifs 4, 10, 11, 12 w.r.t. Generalized ER is roughly consistent with Song et al.

  • The overall level of deviation is smaller than Song et al.

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Three-Cell Motifs Frequencies

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  • The overrepresentation is gone when comparing with CFG.

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Three-Cell Motifs Frequencies

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  • CFG predicts frequencies better than the generalized ER for most motifs.

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Clustering Coefficient

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  • CFG predicts clustering coefficients closer to observation.

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Common Neighbor Rule

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  • CFG also implies “common neighbor rule” (Perin et al. 2011)

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Main Conclusions

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  • Consistent with previous studies, we found the frequencies of two-cell and three-cell motifs derivate significantly from the ER model.

  • However, with a degree-preserving configuration model, our analysis suggests that the “non-randomness” of cortical connections are more subtle than previously supposed.

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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J. Alexander Bae

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“In-connection density”

2

Length ( )

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Lien & Scanziani, 2013; Also see Li et al., 2013

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“In-connection density”

2

Length ( )

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Pyramidal cells receiving more connections from nearby cells

show stronger responses.

r=0.46, p=0.005

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Response

Trial

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Response

Trial

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Intermittency

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Intermittency

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Intermittency

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Intermittency is correlated with in-connection density, while it is NOT correlated with total in-synapse density.

Connections within pyramidal subgraph

Synapses within�the entire graph

r=−0.49, p=0.003

r=0.05, p=0.757

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Pyramidal cells receiving more connections from nearby cells show stronger and more reliable responses.

Connections within pyramidal subgraph

Synapses within�the entire graph

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Okun et al., 2015

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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125/364 validated

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125 cells

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See Chang, Honick and Reynolds, 2006; Lewis et al., 2018

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Li et al., 2004

Drp1-K38A

Drp1-wt

Control

GFP MitoDsRed Merge

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r=0.62, p<3.3 × 10-8

r=0.34, p=0.005

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Somatic mitochondria are intermediate in size between axonal and dendritic. Mitochondrial density covaries with input synapse density.

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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Casey Schneider-Mizell

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The resource

Motifs

Mitochondria

Functional Data

Interneurons

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Barak Nehoran

Seun Ogedengbe

Sergiy Popovych

Ben Silverman

Will Silversmith

Marissa Sorek

Amy Sterling

Sebastian Ströh

Nick Turner

Ashwin Vishwanathan

Adrian Wanner

Ryan Willie

Kyle Patrick Willie

Alyssa Wilson

Jingpeng Wu

Runzhe (Tony) Yang

Szi-chieh Yu

Zhihao Zheng

Jonathan Zung

Clay Reid

Nuno da Costa

Forrest Collman

Andreas Tolias

Jake Reimer

Sebastian Seung

Alex Bae

Douglas Bland

Austin Burke

Manuel Castro

Celia David

Sven Dorkenwald

Daniela Gamba

Jay Gager

Akhilesh Halageri

Eric Hammerschmith

James Hebditch

May Husseini

Zhen Jia

Devon Jones

Chris Jordan

Nico Kemnitz

Selden Koolman

Kai Kuehner

Kisuk Lee

Ran Lu

Kyle Luther

Thomas Macrina

Claire McKellar

Merlin Moore

Shanka Subhra Mondal

Sarah Morejohn

Shang Mu

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Multiscale and multimodal reconstruction of cortical structure and function

Nick Turner & “Tony” Runzhe Yang

11-5-2020

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Supplementary Slides

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Truncation Effect

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Degree Sequences

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Subgraph of PyCs (> 0μm axon)

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  • 229 nodes, 1264 edges.

  • As the threshold increases, the overrepresentation w.r.t. ER decreases, and CFG becomes closer to ER.

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Subgraph of PyCs (> 300μm axon)

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  • 100 nodes, 622 edges.

  • As the threshold increases, the overrepresentation w.r.t. ER decreases, and CFG becomes closer to ER.

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Full Graph (363 neurons)

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Null Model Comparison

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Better Fit from CFG is Non-Trivial

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Clustering Coefficients

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