[BIC-announce] FW: Killam Lecture TOMORROW

[Jennifer Chew, Ms.]

PLEASE DISCARD IF THIS IS A DUPLICATE.  THANK YOU.  JENNIFER  
 

________________________________

From: MNISTAFF - Montreal Neurological Institute Staff [mailto:MNISTAFF at LISTS.MCGILL.CA] On Behalf Of Enza Ferracane, Ms.
Sent: Monday, September 17, 2007 12:35 PM
To: MNISTAFF at LISTS.MCGILL.CA
Subject: Killam Lecture TOMORROW



*****REMINDER*****

 

KILLAM LECTURE 

 

Speaker:  Afonso C. Silva, PhD

Head, Cerebral Microcirculation Unit

National Institutes of Health

 

Title:  "Spatial, Temporal and Pharmacological Investigations of Cerebrovascular Coupling" 

Place:  de Grandpre Communications Centre

 

Time:  4:00 pm

 

Date:  Tuesday, September 18, 2007

 

------------------------------------------------
Dear Colleagues,

Please join me in attending the Killam seminar of Dr Afonso Silva on Tuesday September 18, 2007.

His talk will surely be of interest to several of you and should improve our understanding of the basis of the signals used in brain imaging studies to map neuronal activity under both physiological and clinical studies.

Looking forward to seeing you there.

Edith
PS: Please note small change in the Title of his presentation.


"Spatial, Temporal and Pharmacological Investigations of Cerebrovascular Coupling" 
Afonso C. Silva, Ph.D., Head, Cerebral Microcirculation Unit,
Laboratory of Functional and Molecular Imaging, NINDS, NIH.

ABSTRACT:
Unlike any other organ of the body, the brain is critically dependent on a continuous blood supply. Due to its high energy demands, the brain operates under a tight coupling of neuronal electrical activity to the hemodynamic regulation of energy supply and waste removal. The "cerebrovascular coupling" entails a complex, highly redundant array of signaling mechanisms aimed at maintaining homeostasis of the brain parenchyma by regulating cerebral blood flow (CBF) on a precise spatial and temporal domain. There is increased evidence that such mechanisms result from an integrated action of neurons, glia and blood vessels, which form a "neurovascular unit" acting at the cellular level to regulate local CBF. Disruption of these mechanisms causes brain dysfunction and disease. The principal aims of my lab are to understand the mechanisms of regulation of cerebral blood flow (CBF) during increased focal brain activity, and to understand how the cerebral blood flow adjustments relate, in space and in time, to the spatial and temporal changes in electrical activity. Our research uses small animal models to study the cerebral microcirculation and its relationship to brain anatomy, as well as its reactivity to functional stimulation. Our general experimental approach consists primarily of applying somatosensory stimuli to the animals while using functional magnetic resonance imaging (fMRI) techniques to image the intact brain at high spatial resolution. fMRI allows us to monitor, in four dimensions, the functional changes in brain hemodynamics occurring during increased neural activity. Electrophysiological recordings performed either simultaneously, or in parallel to the fMRI, provide monitoring of the changes in neural activity. Complementary to the use of fMRI, we use two-photon laser scanning microscopy to directly visualize individual capillaries and their associated changes in volume and flux of red-blood cells during brain activation. These measurements have the strong potential to allow a direct observation of the neurovascular unit at work, while further establishing the spatial domain of focal CBF changes.
 
References
1. Silva AC, Kellman P, Koretsky AP, Duyn JH (2007) fMRI impulse response for BOLD and CBV contrast in rat somatosensory cortex. Magn. Reson. Med., 57(6):1110:1118
2. Stefanovic B,  Schwindt W, Hoehn M, Silva AC (2007) Functional uncoupling of hemodynamic from neuronal response by inhibition of neuronal nitric oxide synthase. J. Cereb. Blood Flow Metab., 27(4):741-754
3. Stefanovic B, Bosetti F, Silva AC (2006) Modulatory role of cyclooxygenase-2 in cerebrovascular coupling. Neuroimage 32(1):23-32
4. Gsell W, Burke M, Wiedermann, Dauphin F, Bonvento G , Silva AC, Bührle C, Hoehn M and Schwindt W (2006) Differential effects of NMDA and AMPA glutamate receptors on fMRI signals and evoked neuronal activity during forepaw stimulation of the rat. J. Neurosci., 26(33):8409-8416
5. Hutchinson EB, Stefanovic B, Koretsky AP, Silva AC (2006) Spatial flow-volume dissociation of the cerebral microcirculatory response to mild hypercapnia. Neuroimage 32(2):520-530