Whole brain cellular-level activity mapping once a second
March 19, 2013
Brain activity imaging of a whole zebrafish brain at single-cell resolution (credit: Misha B Ahrens, Philipp J Keller/Nature Methods)
Neuroscientists at Howard Hughes Medical Institute have mapped the activity of nearly all the neurons in a vertebrate brain at cellular resolution, with signficant implications for neuroscience research and projects like the proposed Brain Activity Map (BAM).
Fast volumetric imaging of the larval zebrafish brain with light-sheet microscopy (credit: Misha B Ahrens, Philipp J Keller/Nature Methods)
The researchers used high-speed light sheet microscopy to image the activity of 80% of the neurons in the brain (which is composed of ~100,000 neurons) of a fish larva at 0.8 Hz (an image every 1.3 seconds), with single-cell resolution.
This represents the first technology that achieves whole brain imaging of a vertebrate brain at cellular resolution with speeds that approximate neural activity patterns and behavior, as Nature Methods methagora blog noted.
The authors saw correlated activity patterns at the cellular level that spanned large areas of the brain — pointing to the existence of broadly distributed functional circuits.
The next steps will be to determine the causal role that these circuits play in behavior — something that will require improvements in the methods for 3D optogenetics, the blog said. Obtaining the detailed anatomical map of these circuits will also be key to understand the brain’s organization at its deepest level.
References:
- Misha B Ahrens, Philipp J Keller, Whole-brain functional imaging at cellular resolution using light-sheet microscopy, Nature Methods, 2013, DOI: 10.1038/nmeth.2434
- Misha B Ahrens, Philipp J Keller, Whole-brain functional imaging at cellular resolution using light-sheet microscopy - Supplementary Information, Nature Methods, 2013 (open access)
Comments (7)
by asiwel
This zebrafish research is fascinating. If you search KurzweilAI.net using “zebrafish” as the search term, you get at least 27 hits … all of which are very interesting articles which have elicited numerous interesting and thoughtful comments. That’s almost enough for a new “strand” following this subject.
by Camaxtli
I wonder how good the resolution has to be (spatial/temporal) before the activity can be mined for patterns that could be applied to robotics.
by Vin
I guess can be done immediately – Map hierarchically to robot analogues, graft on extra as resolution improves, can gain how hierarchical levels map to sophistication of result. Also use Miguel Nicolelis work to ‘mind meld’ analogous brain areas of other animals (i.e me) with the fish! It must be fun to have a luminous brain.
by Giulio Prisco
Yet another step in the right direction, one more sign to show that we will get “there” eventually.
by Dr. X
They would need to improve scanning speed to around 40ms or even lower to get real time data (because of brains asynchronous nature).
Human brain clocked at around ~25 Hz, neurons fire 25 times per second max, very low number but brain compensates by extreme computational complexity to perform recognition tasks etc.
by Henry Olders, MD
Could you provide a reference please for human neurons having a maximum firing frequency of 25 Hz?
by Robert Cunningham
http://www.noteaccess.com/APPROACHES/ArtEd/ChildDev/1cNeurons.htm
These are notes based on “Coon, Dennis. Introduction to Psychology, Exploration and Application. St. Paul: West Publishing Company, 1989″
*** From that reference ***
2. THE NERVE IMPULSE (primarily an electrical event): Each neuron is like a tiny biological battery ready to be discharged. It takes about one-thousandth of a second for a neuron to fire an impulse and return to its resting level. Thus, a maximum of 1,000 nerve impulses per second is possible. However, firing rates of 1 per second to 300-400 per second are more typical.