Université de Fribourg

Improved in vivo two-photon imaging after blood replacement by perfluorocarbon

Haiss, F. ; Jolivet, R. ; Wyss, M. T. ; Reichold, J. ; Ben Braham, Nasser ; Scheffold, Frank ; Krafft, M. P. ; Weber, B.

In: The Journal of Physiology, 2009, vol. 587, p. 3153-3158

Two-photon microscopy is a powerful method in biomedical research that allows functional and anatomical imaging at a subcellular resolution in vivo. The technique is seriously hampered by absorption and scattering of light by blood, which prevents imaging through large vessels. Here, we demonstrate in the rat cerebral cortex that blood replacement by perfluorocarbon emulsion, a compound also used...

Université de Fribourg

Laser speckle imaging with an active noise reduction scheme

Völker, Andreas C. ; Zakharov, Pavel ; Weber, B. ; Buck, F. ; Scheffold, Frank

In: Optic Express, 2005, vol. 13, no. 24, p. 9782-9787

We present an optical scheme to actively suppress statistical noise in Laser Speckle Imaging (LSI). This is achieved by illuminating the object surface through a diffuser. Slow rotation of the diffuser leads to statistically independent surface speckles on time scales that can be selected by the rotation speed. Active suppression of statistical noise is achieved by accumulating data over...

Université de Fribourg

Optical imaging of the spatiotemporal dynamics of cerebral blood flow and oxidative metabolism in the rat barrel cortex

Weber, B. ; Burger, C. ; Wyss, M. T. ; Schulthess, G. K. von ; Scheffold, Frank ; Buck, Alfred

In: European Journal of Neuroscience, 2004, vol. 20, p. 2664-2670

Oxidative metabolism and cerebral blood flow (CBF) are two of the most important measures in neuroimaging. However, results from concurrent imaging of the two with high spatial and temporal resolution have never been published. We used flavoprotein autofluorescence (AF) and laser speckle imaging (LSI) in the anaesthetized rat to map oxidative metabolism and CBF in response to single vibrissa...