Navigation auf


Institute of Pharmacology and Toxicology Experimental Imaging and Neuroenergetics

Astrocytes & Intercellular Communication

A) Spontaneous astrocyte calcium signals (white arrows) as detected by astrocyte specific expression of a genetic calcium indicator in vivo. B) Four types of regions of interest based on cellular structure: AC- astrocyte soma, BR- astrocyte branches, EF- vascular endfeet, and AP-astropil. C) Example fluorescence intensity traces for each of the 4 ROIs indicated in B over 20 min of two photon imaging. D) Neuron specific expression of genetic calcium indicator. E) Example fluorescence intensity traces of 3 neurons. Each trial was 5 seconds long with 1 sec baseline, 1 sec of 90Hz whisker stimulation (purple bars) and 3 sec of imaging.

Astrocytes have emerged as major players in intercellular signaling, which likely contribute to brain information processing, synaptic plasticity and neurovascular coupling. Astrocyte intracellular calcium signals are central to this communication and are triggered by neurotransmitter receptors in response to synaptic input. Recent evidence illustrates different populations of astrocyte calcium signals can occur, which vary in subcellular location, intensity and duration. Through the use of genetic calcium indicators in vivo our lab is interested in examining astrocyte calcium signaling during several processes.

Cortical Plasticity

Astrocytes have recently been shown to influence cortical plasticity through calcium and acetylcholine-dependent mechanisms. We are interested in studying changes in astrocyte calcium signaling during the onset of plasticity and correlating these changes with alterations in neuronal firing rates.

Neurovascular Coupling

In brain slices, neuronal activity stimulates calcium signals in astrocytes, which cause the release of chemicals that increase blood flow. Astrocyte calcium signals are complex and different types of signals have been identified, but characteristics of the signals involved in neurovascular coupling in vivo are unknown. We are currently using in vivo two-photon techniques to determine the differential aspects of astrocyte calcium signaling during neurovascular coupling with the goal of better understanding astrocyte information processing and the signaling relationship between neurons, astrocytes, and brain arteries.

Weiterführende Informationen

Project Details

Responsible Person:
Dr Jill Stobart
Phone: +41 44 635 60 87

Prof. Fritjof Helmchen, Brain Research Institute, University of Zurich