Astrocyte responses to neuronal activity.
During the past few years, it has been established that astrocytes sense neuronal activity and are involved in signal transmission. Neuronal stimulation triggered electrophysiological and/or Ca(2+) responses in astrocyte cultures and in acute brain slices. Present even within one given brain region, different pathways of neuron-to-astrocyte communication involving different receptor systems have been described. These mechanisms include glutamatergic and NO-mediated signaling. Neuron-to-astrocyte signaling can be confined to subcellular compartments, the microdomains, or it can activate the entire cell. It can even trigger a multicellular response in astrocytes, a Ca(2+) wave. This form of astrocyte long-range signal propagation can occur independently, in pure astrocyte cultures, but it can also be triggered by neuronal activity. Astrocytes also exhibit spontaneous Ca(2+) activity. Neuronal activity in acute brain slices can organize this activity into complex synchronous networks. One of the functional consequences of neuron-to-astrocyte signaling might be the neuronal control of microcirculation using astrocytes as a mediator.
Schipke
Carola G
CG
Max Delbrück Center for Molecular Medicine (MDC) Berlin, Germany.
Kettenmann
Helmut
H
Max Delbrück Center for Molecular Medicine (MDC) Berlin, Germany.
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D001921:Brain / Q000098:blood supply / Q000166:cytology / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D006801:Humans; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology