Recent Technology Reviews
Brain Preservation Foundation President Kenneth Hayworth has recently published a technical review paper discussing how extensions of existing technology would be capable of extracting the entire connectome of a chemically preserved human brain:
Hayworth, K. J. (2012) Electron Technology for Whole Brain Neural Circuit Mapping. IJMC Volume: 4, Issue: 1, pp. 87-108 [pdf of uncorrected proof]
An excellent new review of the four leading technologies in connectomics research:
Briggman, K.L. & Bock, D.D. (2011) Volume electron microscopy for neuronal circuit reconstruction. Curr Op in Neurobiology 22 pp.1-8
Researchers and others interested in the current state of development of technologies of brain preservation and connectomics/brain pattern restoration may enjoy the following papers. The new field of connectomics is undergoing particularly rapid development at present. Visit NLM Pub Med for more.
Brief overview on the state of the art in chemical preservation research:
Papers describing the state of the art in chemical brain preservation:
Palay et al. 1962. Fixation of neural tissues for electron microscopy by perfusion with solutions of osmium tetroxide.
Oldmixon et al. 1985. Perfusion dehydration fixes elastin and preserves lung air-space dimensions.
Excellent reference books describing theory and protocols for perfusion fixation of tissue and solid organs:
Hyat, M.A. 2000. Principles and Techniques of Electron Microscopy: Biological Applications, Fourth Ed., Cambridge U. Press.
Kiernan, J.A. 2008. Histological and Histochemical Methods: Theory and Practice, Fourth Ed., Cold Spring Harbor Lab Press.
Brief overview on the state of the art in cryopreservation research:
Papers describing the state of the art in cryopreservation:
Darwin et al. 1995. Effect of human cryopreservation protocol on the ultrastructure of the canine brain.
Pichugin et al. 2006. Cryopreservation of rat hippocampal slices by vitrification.
Fahy et al. 2009. Physical and biological aspects of renal vitrification.
Connectomics, Imaging, and Neural Circuit Mapping
There are a number of imaging and neural circuit mapping technologies that are rapidly improving in price/performance today. Any one of these might be used to complete a small animal (worm, insect, zebrafish), a mouse, and later, a human connectome in coming years. Which will ultimately be proven most cost effective is not clear at present, and may vary from application to application and lab to lab. Current viable technologies include:
1. Serial Block Face Scanning Electron Microscopy (SBFSEM)
2. Focused Ion Beam Scanning Electron Microscopy (FIBSEM)
3. Ultrathin sectioning and automated tape collection for SEM
4. Electron tomography on thick cut sections (TEM or SEM)
5. X-ray tomography (either on vitrified tissue or stained plastic embedded tissue)
6. Atomic force scanning microscopy of block face in preserved tissue.
BPF Brief on The NIH Human Connectome Project:
What is a connectome?
Brief overview on the state of the art in high-throughput volume EM imaging of brain tissue:
Papers describing the state of the art in high-throughput volume EM imaging of brain tissue
Denk et al. 2004. Serial block-face scanning electron microscopy to reconstruct three-dimensional tissue nanostructure.
Knott et al. 2008. Serial section scanning electron microscopy of adult brain tissue using focused ion beam milling.
ATLUM project website:
Papers describing recent imaging technology advances:
Schneider et al. 2010. Three-dimensional cellular ultrastructure resolved by X-ray microscopy.