Journal Article

Neuron-to-astrocyte signaling is central to the dynamic control of brain microcirculation

Pozzan, Tullio, Hossmann, Konstantin-A., Gobbo, Sara, Carmignoto, Giorgio, Rosengarten, Bernhard, Zonta, Micaela, Angulo, María Cecilia

2003

Overview

The cellular mechanisms underlying functional hyperemia—the coupling of neuronal activation to cerebral blood vessel responses—are not yet known. Here we show in rat cortical slices that the dilation of arterioles triggered by neuronal activity is dependent on glutamate-mediated [Ca 2+ ] i oscillations in astrocytes. Inhibition of these Ca 2+ responses resulted in the impairment of activity-dependent vasodilation, whereas selective activation—by patch pipette—of single astrocytes that were in contact with arterioles triggered vessel relaxation. We also found that a cyclooxygenase product is centrally involved in this astrocyte-mediated control of arterioles. In vivo blockade of glutamate-mediated [Ca 2+ ] i elevations in astrocytes reduced the blood flow increase in the somatosensory cortex during contralateral forepaw stimulation. Taken together, our findings show that neuron-to-astrocyte signaling is a key mechanism in functional hyperemia.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: Afferent Pathways - physiology / Animal Genetics and Genomics / Animals / Animals, Newborn / Astrocytes / Astrocytes - cytology / Astrocytes - drug effects / Astrocytes - metabolism / Behavioral Sciences / Biological Techniques / Biomedical and Life Sciences / Biomedicine / Brain / Brain - blood supply / Brain - cytology / Brain - metabolism / Calcium Signaling - drug effects / Calcium Signaling - physiology / Cell Communication - drug effects / Cell Communication - physiology / Cerebral Cortex - blood supply / Cerebral Cortex - cytology / Cerebral Cortex - metabolism / Cerebrovascular Circulation - physiology / Electric Stimulation / Enzyme Inhibitors - pharmacology / Excitatory Amino Acid Antagonists - pharmacology / Glutamic Acid - metabolism / Microcirculation - cytology / Microcirculation - drug effects / Microcirculation - metabolism / Neurobiology / Neurons / Neurons - cytology / Neurons - drug effects / Neurons - metabolism / Neurosciences / Nitric Oxide - metabolism / Physiological aspects / Rats / Rats, Wistar / Receptors, Metabotropic Glutamate - antagonists & inhibitors / Receptors, Metabotropic Glutamate - metabolism / Signal Transduction - drug effects / Signal Transduction - physiology / Vasodilation - drug effects / Vasodilation - physiology / Vasodilator Agents - pharmacology