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.
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.
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.