Abstract
Fluorescence correlation spectroscopy (FCS) can be used to measure kinetic properties of single molecules in drops of solution or in cells. Here we report on FCS measurements of tetramethylrhodamine (TMR)-dextran (10 kDa) in dendrites of cultured mitral cells of Xenopus laevis tadpoles. To interpret such measurements correctly, the plasma membrane as a boundary of diffusion has to be taken into account. We show that the fluorescence data recorded from dendrites are best described by a model of anisotropic diffusion. As compared to diffusion in water, diffusion of the 10-kDa TMR-dextran along the dendrite is slowed down by a factor 1.1-2.1, whereas diffusion in lateral direction is 10-100 times slower. The dense intradendritic network of microtubules oriented parallel to the dendrite is discussed as a possible basis for the observed anisotropy. In somata, diffusion was found to be isotropic in three dimensions and 1.2-2.6 times slower than in water.
Full Text
The Full Text of this article is available as a PDF (688.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bischofberger J., Schild D. Different spatial patterns of [Ca2+] increase caused by N- and L-type Ca2+ channel activation in frog olfactory bulb neurones. J Physiol. 1995 Sep 1;487(Pt 2):305–317. doi: 10.1113/jphysiol.1995.sp020881. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brock R., Hink M. A., Jovin T. M. Fluorescence correlation microscopy of cells in the presence of autofluorescence. Biophys J. 1998 Nov;75(5):2547–2557. doi: 10.1016/S0006-3495(98)77699-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Czesnik D., Nezlin L., Rabba J., Müller B., Schild D. Noradrenergic modulation of calcium currents and synaptic transmission in the olfactory bulb of Xenopus laevis tadpoles. Eur J Neurosci. 2001 Mar;13(6):1093–1100. doi: 10.1046/j.0953-816x.2001.01479.x. [DOI] [PubMed] [Google Scholar]
- Gennerich A., Schild D. Fluorescence correlation spectroscopy in small cytosolic compartments depends critically on the diffusion model used. Biophys J. 2000 Dec;79(6):3294–3306. doi: 10.1016/S0006-3495(00)76561-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Politz J. C., Browne E. S., Wolf D. E., Pederson T. Intranuclear diffusion and hybridization state of oligonucleotides measured by fluorescence correlation spectroscopy in living cells. Proc Natl Acad Sci U S A. 1998 May 26;95(11):6043–6048. doi: 10.1073/pnas.95.11.6043. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schwille P., Bieschke J., Oehlenschläger F. Kinetic investigations by fluorescence correlation spectroscopy: the analytical and diagnostic potential of diffusion studies. Biophys Chem. 1997 Jun 30;66(2-3):211–228. doi: 10.1016/s0301-4622(97)00061-6. [DOI] [PubMed] [Google Scholar]
- Schwille P. Fluorescence correlation spectroscopy and its potential for intracellular applications. Cell Biochem Biophys. 2001;34(3):383–408. doi: 10.1385/CBB:34:3:383. [DOI] [PubMed] [Google Scholar]
- Schwille P., Haupts U., Maiti S., Webb W. W. Molecular dynamics in living cells observed by fluorescence correlation spectroscopy with one- and two-photon excitation. Biophys J. 1999 Oct;77(4):2251–2265. doi: 10.1016/S0006-3495(99)77065-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trombley P. Q., Westbrook G. L. Excitatory synaptic transmission in cultures of rat olfactory bulb. J Neurophysiol. 1990 Aug;64(2):598–606. doi: 10.1152/jn.1990.64.2.598. [DOI] [PubMed] [Google Scholar]
- Wachsmuth M., Waldeck W., Langowski J. Anomalous diffusion of fluorescent probes inside living cell nuclei investigated by spatially-resolved fluorescence correlation spectroscopy. J Mol Biol. 2000 May 12;298(4):677–689. doi: 10.1006/jmbi.2000.3692. [DOI] [PubMed] [Google Scholar]
- Widengren J., Rigler R. Fluorescence correlation spectroscopy as a tool to investigate chemical reactions in solutions and on cell surfaces. Cell Mol Biol (Noisy-le-grand) 1998 Jul;44(5):857–879. [PubMed] [Google Scholar]