m8ta
you are not logged in, login. new entry
text: sort by
tags: modified
type: chronology
{1371}
hide / edit[0] / print
ref: -0 tags: nanotube tracking extracellular space fluorescent date: 02-02-2017 22:13 gmt revision:0 [head]

PMID-27870840 Single-nanotube tracking reveals the nanoscale organization of the extracellular space in the live brain

  • Extracellular space (ECS) takes up nearly a quarter the volume of the brain (!!!)
  • Used the intrinsic fluorescence of single-walled carbon nanotubes @ 1um, 845nm excitation, with super-resolution tracking of diffusion.
    • Were coated in phospholipid-polyethylene glycol (PL-PEG), which display low cytotoxicity compared to other encapsulants.
  • 5ul, 3ug/ml injected into the ventricles of young rats; allowed to diffuse for 30 minutes post-injection.
  • No apparent response of the microglia.
  • Diffusion tracking revealed substantial dead-space domains in the ECS.
    • As compared to patch-clamp loaded SWCNTs
  • Estimate from parallel and perpendicular diffusion rates that the characteristic scale of ECS dimension is 80 to 270nm, or 150 +- 40nm.
  • The ECS nanoscale dimensions as visualized by tracking similar in dimension and tortuosity to electron microscopy.
  • Viscosity of the extracellular matrix from 1 to 50 mPa S, up to two orders of magnitude higher than the CSF.
  • Positive control through hyalurinase + several hours to digest the hyaluronic acid.
    • But no observed changes in morphology of the neurons via confocal .. interesting.
    • Enzyme digestion normalized the spatial heterogenaity of diffusion.

{1186}
hide / edit[0] / print
ref: -0 tags: voltage sensitive dyes fluorescent protein date: 01-02-2013 05:08 gmt revision:0 [head]

PMID-20622860 Imaging brain electric signals with genetically targeted voltage-sensitive fluorescent proteins.

  • Interesting: Most fluorescent fusion proteins form intracellular aggregates during long-term expression in mammalian neurons, although this effect appears to be minimal in Aequorea victoria–derived fluorescent proteins.
  • See also {1185}

{566}
hide / edit[5] / print
ref: Sakai-2001.06 tags: voltage scensitive fluorescent protein flourophore VSFP1 endoscope date: 01-24-2012 06:07 gmt revision:5 [4] [3] [2] [1] [0] [head]

http://www.blackwell-synergy.com/doi/full/10.1046/j.0953-816x.2001.01617.x PMID-11454036[0]

____References____

[0] Sakai R, Repunte-Canonigo V, Raj CD, Knöpfel T, Design and characterization of a DNA-encoded, voltage-sensitive fluorescent protein.Eur J Neurosci 13:12, 2314-8 (2001 Jun)
[1] van Roessel P, Brand AH, Imaging into the future: visualizing gene expression and protein interactions with fluorescent proteins.Nat Cell Biol 4:1, E15-20 (2002 Jan)
[2] Guerrero G, Siegel MS, Roska B, Loots E, Isacoff EY, Tuning FlaSh: redesign of the dynamics, voltage range, and color of the genetically encoded optical sensor of membrane potential.Biophys J 83:6, 3607-18 (2002 Dec)
[3] Jung JC, Mehta AD, Aksay E, Stepnoski R, Schnitzer MJ, In vivo mammalian brain imaging using one- and two-photon fluorescence microendoscopy.J Neurophysiol 92:5, 3121-33 (2004 Nov)
[4] Sjulson L, Miesenböck G, Optical recording of action potentials and other discrete physiological events: a perspective from signal detection theory.Physiology (Bethesda) 22no Issue 47-55 (2007 Feb)