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1. Our Lab In The Media

 

 

 

 

 

1. Our research on complete protection from stroke by mild sensory stimulation (less than 5 minutes of single whisker stimulation) has been described in newspapers, magazines, and web-sites all over the world.  Here are the links for some examples:

Scientific American Mind (07-2013): Click for PDF

Los Angeles Times (11-17-2011):

http://www.latimes.com/health/boostershots/la-heb-stroke-injury-rats-20111117,0,3950719.story

Los Angeles Times (11-20-2010):

http://articles.latimes.com/2010/nov/19/health/la-he-stroke-stimulation-20101118

Science News Magazine (11-19-2010):

http://www.sciencenews.org/view/generic/id/65616/title/-Flick_of_a_whisker_can_prevent_stroke_damage_in_rats

2. Second Edition of In Vivo Optical Imaging of Brain Function
The second edition of the book: In Vivo Optical Imaging of Brain Functions now available from CRC Press (2009). It is updated to reflect continuous development of a variety of invasive and non-invasive optical techniques used to study the living brain in animals and humans at various spatial and temporal resolutions. Topics include: voltage-sensitive dyes imaging in awake behaving animals, imaging based on genetically encoded probes, imaging of mitochondrial auto-fluorescence as a tool for cortical mapping, using pH-sensitive dyes for functional mapping, modulated imaging, 2-photon imaging principles, calcium imaging of neuronal activity using-2-photon microscopy, Fourier approach to optical imaging, intrinsic signal optical imaging in animals and humans, scattered light imaging, diffuse optical tomography and imaging based on fast optical signals.

3. Evaluation of some of our recent papers by the "Faculty of 1000":

Recommended
 
 

Mild sensory stimulation protects the aged rodent from cortical ischemic stroke following permanent middle cerebral artery occlusion.
Lay, C.C., Davis, M.F., Chen-Bee, C.H. and Frostig, R.D. Journal of the American Heart Association (JAMA), 2012. DOI - 10.1161/JAHA.112.001255.

Faculty Member   Comments

Naoun Isaa
University of Chicago

 

 

 

In ischemic strokes, the level of debilitation is often determined by the amount of collateral circulation a patient has. However, there is little known about the factors that regulate collateral circulation. This paper by Lay et al. rounds out a great series from the Frostig lab that both develops a mouse model for studying collateral circulation in stroke and demonstrates a simple way of improving collateral circulation in the model system. If their findings - that somatosensory stimulation within the first 3 hours of the onset of ischemia can open collaterals to a brain region at risk - translate into human patients, a new set of therapeutic interventions for acute ischemic stroke could be around the corner.

Evaluated February 21 2013

Must Read
F1000 Factor 6.0
  Mild sensory stimulation completely protects the adult rodent cortex from ischemic stroke.
Lay CC, Davis MF, Chen-Bee CH, Frostig RD PLoS One. 2010; 5(6):e11270
Faculty Member   Comments

Mike Johnson

Kennedy Krieger Institute, USA

 

This article is interesting because it shows that cortical activity can have a protective or worsening effect on damage from middle cerebral artery ischemia in a rodent model depending on timing. If replicated in humans, the result implies that simple sensory stimulation programs could be used along with revascularization interventions to improve outcome from stroke

The authors used a well established model of cortical plasticity in which repetitive stimulation of a single whisker on the snout of an adult rat leads to activation of a specific area of contralateral somatosensory cortex. They produced permanent occlusion in the middle cerebral artery (MCAO) providing blood to this cortical area, and found that whisker stimulation at the time of MCAO or one hour afterward protected the cortex completely from injury. In contrast, stimulation at 3 hours after MCAO enhanced injury. The mechanism for the protective effect is unclear but could be related to enhanced cortical perfusion and/or release of inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA). There is growing interest in clinical stroke neurorehabilitation in the beneficial effect of repetitive limb exercises and sensory stimulation on recovery from chronic stroke {1}, and this paper highlights a potential protective effect of sensory stimulation on stroke in the acute period as well.

References:
{1} Celnik et al. Arch Phys Med Rehabil 2007, 88:1369-76

Evaluated April 14 2011

Recommended
F1000 Factor 3.0
 

Large-scale organization of rat sensorimotor cortex based on a motif of large activation spreads.
Frostig RD, Xiong Y, Chen-Bee CH, Kvasnák E, Stehberg J J Neurosci 2008 Dec 3 28(49):13274-84

Faculty Member Comments

Kathleen Rockland
RIKEN, Japan
NEUROSCIENCE
New Finding

 

 

 

 

 

 


 

 

 

 

 

 

The authors present physiological evidence, from monitoring supra- and subthreshold activations in rat barrel cortex and adjacent areas after single whisker activation, for a concurrent dual organization of neocortex, with both topographic and non-topographic components. They further raise the interesting possibility that the more extensively investigated topographic specificity of evoked sensory activity could be extracted from the large-scale non-specific activation.

Research on sensory cortical organization has overwhelmingly emphasized topographic organization and its putative basis in "driving" "bottom-up" signalling from the periphery via the thalamus. A contrast is then made with the great "modulatory" systems (serotonergic, dopaminergic, noradrenergic, cholinergic) as well as, to some extent, with "top-down" cortical feedback connections, which are more spatially divergent and by implication more "modulatory". In this study, the authors take a different view, which gives new importance to non-topographic connections. They show cortical activations as "spilling over" across conventional areas and suggest that the activity spread is due to sparse long-range horizontal connections. The experimental documentation for this claim -- of labeled fibers invading neighboring territories -- is plausible, but immediately raises the question of whether there is a specialized subset of pyramidal neurons that give rise to these particular long-range, non-topographical connections. While the proposal appears novel and/or an outlier view of cortical organization, the authors accurately relate their findings to other work on multisensory processing and to early thinking of Pavlov on activity spreads as a potential underlying mechanism for plasticity and associative learning.

Evaluated 12 Dec 2008

Must Read
F1000 Factor 6.0
Naturalistic experience transforms sensory maps in the adult cortex of caged animals.
Polley DB, Kvasnák E, Frostig RD
Nature 2004 May 6 429(6987):67-71
Faculty Member Comments

Kathleen Rockland
RIKEN, Japan
NEUROSCIENCE
New Finding

 

 

 

The authors use a combination of optical imaging and multi-site extracellular recording to demonstrate that simple transferral of adult rats from standard laboratory cages to a naturalistic habitat induces a large-scale functional refinement of cortical sensory maps in the barrel cortex.

Cortical whisker representation contracted by 46% after 4-6 weeks in the naturalistic environment, and neuronal receptive fields became smaller and sharper, specifically in layers 2,3. The results raise important questions concerning functional plasticity, laminar specializations, and, not least, the ways in which the experimental paradigm may influence results.

Evaluated 18 May 2004