title: Astrocytes discriminate and selectively respond to the activity of a subpopulation of neurons within the barrel cortex.
abstract: Sensory information from single whiskers in rodents projects to defined morphological units in the cortex, the barrels. We found that astrocytes selectively respond with an increase in the cytosolic Ca(2+) concentration to activation of layer 4 neurons, the input cells of the barrel columns. The neuronal Ca(2+) signal also spread across barrel column borders mainly in layer 2/3, but the glutamate-mediated astrocyte response stayed restricted to the barrel column. In contrast, when interfering with inhibitory pathways by blocking either purinergic, adenosine or gamma-aminobutyric acid(A) receptors, the stimulation activated a Ca(2+) response in a much larger astrocyte population no longer restricted to the borders of the barrel column. We also observed spontaneous and evoked Ca(2+) activity in the synaptic target cells of layer 4 neurons, the layer 2/3 pyramidal cells, but again, we never recorded Ca(2+) responses in astrocytes following activity in this neuronal population. Our data show that astrocytes can discriminate and selectively respond to the activity of a subpopulation of excitatory neurons within a given brain region. This selectivity in the astrocyte response describes a new level of complexity and integration in the reaction of astrocytes to neuronal activity.
authors.affiliation: Department of Psychiatry and Psychotherapy, Campus Benjamin Franklin, Charité-University Medicine Berlin, D-12200 Berlin, Germany.
authors.forename: Carola G
authors.initials: CG
authors.lastname: Schipke
authors.forename: Brigitte
authors.initials: B
authors.lastname: Haas
authors.forename: Helmut
authors.initials: H
authors.lastname: Kettenmann
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D021461:Animals, Outbred Strains; D001253:Astrocytes / Q000166:cytology* / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002450:Cell Communication / Q000502:physiology; D000075302:Connexin 30; D018031:Connexin 43 / Q000235:genetics; D017630:Connexins / Q000235:genetics; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D017629:Gap Junctions / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D009924:Organ Culture Techniques; D058914:Purinergic Antagonists; D043882:Receptors, Cannabinoid / Q000502:physiology; D011950:Receptors, Cholinergic / Q000502:physiology; D011983:Receptors, Purinergic / Q000502:physiology; D011985:Receptors, Serotonin / Q000502:physiology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013003:Somatosensory Cortex / Q000166:cytology / Q000502:physiology*; D014738:Vibrissae / Q000294:innervation
chemical_list: D000075302:Connexin 30; D018031:Connexin 43; D017630:Connexins; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; C100629:Gjb6 protein, mouse; D058914:Purinergic Antagonists; D043882:Receptors, Cannabinoid; D011950:Receptors, Cholinergic; D011983:Receptors, Purinergic; D011985:Receptors, Serotonin; D026941:Sodium Channel Blockers; D009569:Nitric Oxide; D018698:Glutamic Acid