A Science Driven Life

An un-edited blog about science, discovery, technology, travel and the occasional whiskey

Posts Tagged ‘brain

Dendrite Pruning and Optical Methods in Neuroscience

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Screen Shot 2014-04-03 at 11.07.57 AMAs always this is meant to be a brief overview of a paper (and the methods used in neuroscience) I happened to have found interesting- for more details please refer to the manuscript itself.

I enjoyed reading a relatively recent paper published in Science from group in Japan (Kazuo Emoto, The University of Tokyo)  that suggests a role for Ca2+ signaling in dendritic pruning, a house-cleaning function in neurons that has been shown to be very important in learning and memory, as well as experience and some forms of cognitive deficits (such as autism and neurodegeneration).

Dendrites are highly branched areas of the cell that act as antennae receive information from neighboring cell.  Pruning refers to a highly complex, regulated, activity dependent process in which connections that are non-essential to the formation of the developing brain are cleaved.

In pruning, our neurons clean house.  Unnecessary connections formed during development are trashed as a way to reduce clutter and improve accuracy and efficiency of signaling.  Many of the basic mechanisms behind how pruning works have been identified.  Specific cascades of enzymes (caspases) as well as a key self-destruction pathway (proteosome-ubiquitin) work together to rid individual neurons of unnecessary connections.  While a lot is known about the processes that regulate the pruning, very little is known about the signaling that tells which dendritic arbors (branches of dendrites) are to be pruned and which of those is to be kept as a part of the neural network.

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Written by Michael Mohammadi

April 15, 2014 at 15:37

Science Technique: Making brains clear – bringing clarity to fluorescence imaging and CLARITY!

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Screen Shot 2013-04-11 at 12.32.23 AM

Image from Chung et al, 2013 – Nature

by Michael Mohammadi

Clear Lipid-echanged Acrylamide-hybridized (Anatomically) Rigid Imaging/Immunostaining/In situ hybridization-compatible Tissue-hYdrogel.

Or just CLARITY.  Whatever you call it, this newly published research technique from Karl Deisseroth and colleagues at Stanford University will allow scientists to image far deeper into fixed tissue than ever before.  The images are absolutely stunning.  A youtube video (below) of the data resulting from the first publicatoin on CLARITY went viral on the internet last week and a feature article appeared in the NY Times as well as a number of science sites and blogs.   The majority of these give a brief overview of CLARITY and the implications of the work.  Here I will focus on how scientists make things look colorful, why we do it, and what CLARITY has done to make some really cool and exciting pictures.  I hope to make scientific imaging as well as CLARITY approachable to the non-scientist. Read the rest of this entry »