Neuropil Modelling: Art ...and Science (!!)

As beautifully demonstrated by Gao at al (2019) in dramatic color, by means of the most current imaging technology available (note prior blog), and in B+W by many other researchers (as on the right, Masliah et al, 1990), the neuropil includes several structures and even just the dendrites can be heterogenous and can show a different morphology and texture than the primary pyramidal dendritic shaft of interest (as I have been modelling).  The IMG on the right (figure "B" from Masliah 1990) specifically outlines (in white) neuropil segments which the researchers have opted to not include in their assessment of the relevant neuronal tissue (Hollywood presentations of neural nets further eliminate all of the neuropil).  In an effort, however, to acknowledge the significance of this component of the neuronal tissue (there wouldn't be a brain without neuropil), the issue of modelling separate 'nonspecific' neuropil processes was warranted, and my effort with this is below.  The effort obviously adopts some degree of artistic license, yet still achieves a reasonable degree of organic aesthetic.

---

Clip to Start with Dendritic Closeup

As described in a couple prior blog entries, my neuronal clip will start with a closeup of a few pyramidal cell dendritic processes, then "zoom out" to show full neurons, and then end with a shot portraying a larger segment of a full hippocampus (or perhaps the reverse?).  At this point, the dendrite phase of the clip warranted another round of modelling effort.  Specifically, the Luengo-Sanchez et al (2018) paper portrayed additional dendritic spine morphologies which I should have probably focused on more during my first effort of dendritic spine modelling.  This second modelling effort is shown on the left.

---

OVERALL SCENE COMPOSITE:
The VFX Driven Neurobiological Narrative 

In addition to adding neurofilaments to the scene (first frame below), the scene's 'engagement factor' will will enhanced by escorting the viewer through the inside of a neuron.  Specifically, the camera will enter and then span the longitudinal axis of the neuron to eventually become accompanied by an accelerating action potential (a depolarizing wave of light), which follows a series of neurotransmitters through the neuronal terminus into the synapse.    The initial abrupt arrival of the action potential will occur from behind and above (the camera) and should have some degree of dramatic effect, i.e. the action potential wave of depolarization is intended to essentially hijack one's attention and even the emotional flow of the scene.   Thus, the action potential wave of depolarization essentially drives the narrative of the scene.   

As an aside, given the neurobiological VFX design theme of this blog, it is relevant to highlight that this particular scene strategy serves as merely one possible example of a VFX driven "neurobiological narrative". 

 

Houdini Lx#4: Volcano Crater

This wk found Kelvin's lecture addressing the volcano crater, which included the pyro source and pyro solver.  I asked some stupid questions about node selection and the entry dialogue field. 

A secondary conversation of notable interest for me was a brief tangent addressing the topic of photogrammetry, which is the generation of a 3D model created by simply entering photogrphs of the obj of interest. 

---

Bibliography

Gao R, Asano MS, Upadhyayula S, Pisarev I, Milkie DE, Liu TL, Singh V, Graves A, Huynh GH, Zhao Y, Bogovic J, Colonell J, Ott CM, Zugates C, Tappan S, Rodriguez A, Mosaliganti KR, Sheu SH, Pasolli HA, Pang S, Xu CS, Megason SG, Hess H, Lippincott-Schwartz J, Hantman A, Rubin GM, Kirchhausen T, Saalfeld S, Aso V, Boyden ES, Betzig E. (2019) “Cortical column and whole-brain imaging with molecular contrast and nanoscale resolution.” Science. available at doi: 10.1126/science.aau8302

Luengo-Sanchez S, Fernaud-Espinosa I, Bielza C, Benavides-Piccione R, Larranaga P, Deflipe J. (2018). 3D morphology based clustering and simulation of human pyramidal cell densritic spines.  PLOS Computational Biology.
https://doi.org/10.1371/journal.pcbi.1006221 ​

Masliah E, Terry RD, Alford M, Deteresa R. (1990). Quantitive Immunohistochemistry of Synaptophysin in Human Neocortex.  Journal of Immunohistochemistry and Cytochemistry. 38(6):837-844.