Our goal is to determine the relevance of glial cells, namely astrocytes, for the development and function of synapses in the mammalian CNS. Our current projects are based on our previous findings that glial signals enhance the number and efficacy of synaptic connections in vitro and that one of the synaptogenic factors is cholesterol.

We use two experimental models: first, primary cultures of highly purified CNS neurons, which allow to compare synapse number and efficacy in the presence or absence glial cells. Second, newly generated lines of transgenic mice based on the Cre/loxP system, which allow for temporally controled gene ablation in subsets of astrocytes. We study these models by electrophysiological recordings and standard cell biological and biochemical techniques.

Please visit our homepage at http://pfrieger.gmxhome.de/work/intro.html

Selected papers:

Pfrieger FW (2009) Roles of glial cells in synapse development. Cell Mol Life Sci 66:2037-47.

Nieweg K, Schaller H, Pfrieger FW (2009) Marked differences in cholesterol synthesis between neurons and glial cells from postnatal rats. J Neurochem 109:125-34.

Claudepierre T, Koncina E, Pfrieger FW, Bagnard D, Aunis D, Reber M (2008) Implication of neuropilin 2 / semaphorin 3F in retinocollicular map formation. Dev Dyn 237:3394 - 3403.

Slezak M, Goritz C, Niemiec A, Frisen J, Chambon P, Metzger D, Pfrieger FW (2007) Transgenic mice for conditional gene manipulation in astroglial cells. Glia 55:1565-76.

Goritz C, Thiebaut R, Tessier LH, Nieweg K, Moehle C, Buard I, Dupont JL, Schurgers LJ, Schmitz G, Pfrieger FW (2007) Glia-induced neuronal differentiation by transcriptional regulation. Glia 55:1108-1122.
 
Steinmetz CC, Buard I, Claudepierre T, Nägler K, Pfrieger FW (2006) Regional variations in the glial influence on synapse development in the mouse CNS. J Physiol  577:249-61.

Goritz C, Mauch DH, Pfrieger FW (2005) Multiple mechanisms mediate cholesterol-induced synaptogenesis in a CNS neuron. Mol Cell Neurosci 29:190-201.

Pfrieger FW (2003) Cholesterol homeostasis and function in neurons of the central nervous system. Cell Mol Life Sci 60:1158-1171.

Slezak M, Pfrieger FW (2003) New roles for astrocytes: regulation of CNS synaptogenesis. Trends Neurosci 26:531-535.

Pfrieger FW (2003) Outsourcing in the brain: do neurons depend on cholesterol delivery by astrocytes? Bioessays 25:72-78.

Pfrieger FW (2003) Role of cholesterol in synapse formation and function. Biochem Biophys Acta 1610:271-280.

Mauch DH, Nägler K, Schumacher S, Göritz C, Müller EC, Otto A, Pfrieger FW (2001) CNS synaptogenesis promoted by glia-derived cholesterol. Science 294:1354-1357.

Nagler K, Mauch DH, Pfrieger FW (2001) Glia-derived signals induce synapse formation in CNS neurons. J Physiol 533:665-679.

- transgenic mice

- purification of neurons and astrocytes

- electrophysiological recordings

- immunostaining, protein biochemistry