STARShiP

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Expand to view experiment animation




 1 %%
 2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 3 %					SPINE RADIAL DISTANCE
 4 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 5 
 6 %=================================================
 7 for reN = 1:loops
 8 %=================================================
 9 
10 SGr = reSGr{reN};
11 
12 %--------------------------------------
13 % Make concentric circle annulus
14 %--------------------------------------
15 S1r = round(S1rad);
16 Qhr = S1r/2;
17 Qx = linspace(0,S1r,6);
18 QxL = Qx - Qhr;
19 yL = sqrt(Qhr.^2 - QxL.^2);
20 Qr = sqrt(Qx.^2 + yL.^2);	% Concentric circles




Quantitative Review

The Size of Dendrites

adapted from Sheng and Hoogenraad (2007) FIG: {{#info
Spine.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
  • Dendrite: 1–10 spines per 10 μm
  • Spines: 0.5–2 μm in length
  • PSD: 100 - 300 nm diameter
  • PSD95: within 12 nm of surface
adapted from Harris FIG: {{#info
Dendrite Table.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
  • proximal dendrite diameter: 1 - 3 µm
  • distal dendrite diameter: 0.2 - 2 µm
  • dendrite length: 2000 - 9000 µm
  • dendrite tip to soma: 100 - 200 µm
  • dendrites at soma: 1 - 5
  • dendrite branches (granual): 10 - 30
  • dendrite branches (purkinje): 400-500


Particle Counts

adapted from Sheng and Hoogenraad (2007) FIG: {{#info
Spine.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
  • PSD: 10,000 proteins (or 100 copies of 100 proteins)
  • CaMKIIα: 7.4%
  • CaMKIIβ: 1.3%
  • SynGap: 2.1 pmol/20 μg
  • NMDAR: 20 proteins
  • AMPAR: 15 proteins
  • GluR: 60 subunits, 15 tetramers, 80% or 12 GluR1/GluR2 heteromers
  • PSD95: within 12 nm of surface


Diffusion Rates

from Choquet 2010 FIG: {{#info
ChoquetDiffusionRate1.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
  • extrasynaptic: 0.1 µm2⁄s
  • synaptic: 0.05 µm2⁄s
  • synaptic after glu/gly: 0.01 µm2⁄s


Images

From Sheng and Hoogenraad 2007
  • Spine morphology FIG: {{#info: Spine.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
From Harris KM and Weinberg 2012
  • Spine morphology FIG: {{#info: Synaptic Buton.png3D reconstruction of a proximal CA3 pyramidal cell dendrite (blue) and a large mossy fiber bouton (translucent yellow). The cut-away in C2 shows synapses (red) onto multiple dendritic spines, some of which are highly branched. The bouton also forms nonsynaptic cell adhesion junctions (fuchsia). CLICK AWAY FROM IMAGE TO CLOSE }}
  • Hippocampal dendrite FIG: {{#info: Hippocampal Neuron.jpg{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}




Choquet 2007 Real Time Receptor Diffusion

This link is to a video of an optimized version from Choquet 2007 (seen below). The dimensions in both 10 x 10 µm. The original version below is run at 4x real-time. The linked video above is slowed to 1x real-time, and all analysis is done at 1:1 video to real-time speed.


Choquet 2007 Real Time Receptor Diffusion Analysis

  • The video represents a 10µm × 10µm section scaled to a 535px × 535px video.
    • 1µm : 53.5px
  • The analysis below documents one instance of Qdot diffusion, between the 6s-7s time points.
  • This instance was chosen because of the clarity of motion and no Qdot flicker.
  • The Qdot (center) moves from pixel location (X:291, Y:302) at 6.78s to (X:319, Y346) at 6.98s
    • That is a distance of 52.2px in 200ms
    • Qdot velocity: Qv ≈ 1µm ⁄ 200ms
    • Note this diffusion rate of 5µm/s is 10-fold higher than the median diffusion rate reported above.
    • An upper bound of 5µm/s means that receptors can move between synapses in fractions of a second.

Figures:

FIG: {{#info: Choquet Diffusion Rate Analysis1.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: Choquet Diffusion Rate Analysis2.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: Choquet RT1.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: Choquet RT2.png{{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}



Receptor Diffusion Rate Best Estimates

  • GABAA: .01 - .05 µm2/s FIG: {{#info: Choquet1 2010.pngChoquet 2010 CLICK AWAY FROM IMAGE TO CLOSE }}




STARShiP Molecular Methods Quantum Dots AMPAR Brownian Motion