; From [http://www.ncbi.nlm.nih.gov/pubmed/22357909 Harris KM and Weinberg 2012]
* Spine morphology {{Fig|[[File:Synaptic Buton.png]]|3D 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).}}
}}
Revision as of 12:51, 2 August 2013
Receptor Diffusion & Cluster Model - ReDiClus Model
Diffusion and Cluster Model of LTP
Diffusion and Cluster Model of LTP
Model Space
The model is simulated in a 3D space with the following parameters
There is a 3D XYZ coordinate grid
The X-Y plane has 60x60 area
The X-Y plane consists of real numbers: -30 to +30
The Z axis is only 2 levels: 0 and -1
0 represents the membrane surface
-1 represents intracellular space
Particle Types
There are 2 types of particles in the simulation
'Red' particle dots represent AMPA receptors
Red dots can randomly diffuse anywhere on the X-Y plane
Red dots only diffuse on the surface Z = 0
'Blue' particle dots represent PSD-95 molecules
Blue dots are contained in predefined PSD areas and cannot leave
Blue dots can exist at the surface Z = 0 or intracellularly Z = -1
Spine morphology FIG: {{#info: 3D 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 }}
Choquet 2007 Real Time Receptor Diffusion
{{{2}}}
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: {{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: {{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: {{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
FIG: {{#info: {{{2}}} CLICK AWAY FROM IMAGE TO CLOSE }}
Receptor Diffusion Rate Best Estimates
GABAA: .01 - .05 µm2/s FIG: {{#info: Choquet 2010 CLICK AWAY FROM IMAGE TO CLOSE }}