Journal Article

Interneuron-specific signaling evokes distinctive somatostatin-mediated responses in adult cortical astrocytes

Marcon, Iacopo, Mariotti, Letizia, Melone, Marcello, Sessolo, Michele, Carmignoto, Giorgio, Bovetti, Serena, Forli, Angelo, Zonta, Micaela, Fellin, Tommaso, Conti, Fiorenzo, Pugliese, Arianna, Chiavegato, Angela, Gómez-Gonzalo, Marta, Lia, Annamaria, Bettler, Bernhard, Viollet, Cécile, Losi, Gabriele, Requie, Linda Maria

2018

Overview

The signaling diversity of GABAergic interneurons to post-synaptic neurons is crucial to generate the functional heterogeneity that characterizes brain circuits. Whether this diversity applies to other brain cells, such as the glial cells astrocytes, remains unexplored. Using optogenetics and two-photon functional imaging in the adult mouse neocortex, we here reveal that parvalbumin- and somatostatin-expressing interneurons, two key interneuron classes in the brain, differentially signal to astrocytes inducing weak and robust GABA B receptor-mediated Ca 2+ elevations, respectively. Furthermore, the astrocyte response depresses upon parvalbumin interneuron repetitive stimulations and potentiates upon somatostatin interneuron repetitive stimulations, revealing a distinguished astrocyte plasticity. Remarkably, the potentiated response crucially depends on the neuropeptide somatostatin, released by somatostatin interneurons, which activates somatostatin receptors at astrocytic processes. Our study unveils, in the living brain, a hitherto unidentified signaling specificity between interneuron subtypes and astrocytes opening a new perspective into the role of astrocytes as non-neuronal components of inhibitory circuits. Interneurons in the neocortex have functional and morphological subtypes. Here, Mariotti and colleagues show that activation of parvalbumin-expressing interneurons evokes depressing calcium responses in astrocytes while somatostatin-expressing interneurons evoke potentiating astrocytic responses.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 14 / 14/19 / 14/28 / 14/69 / 59 / 631/378/1697/1691 / 631/378/2596/1308 / 631/378/87 / 9/74 / Animals / Astrocytes / Astrocytes - metabolism / Brain / Calcium / Calcium - metabolism / Circuits / Genetics / Glial cells / Heterogeneity / Humanities and Social Sciences / Information processing / Interneurons / Interneurons - metabolism / Mice / Mice, Inbred C57BL / Mice, Transgenic / multidisciplinary / Neocortex / Neocortex - cytology / Neocortex - metabolism / Neurogenesis / Neuroimaging / Neuronal Plasticity / Optics / Optogenetics / Parvalbumin / Parvalbumins - metabolism / Patch-Clamp Techniques / Receptors / Receptors, GABA-B - metabolism / Rodents / Science / Science (multidisciplinary) / Signal Transduction / Signaling / Somatosensory Cortex - metabolism / Somatostatin / Somatostatin - metabolism / Somatostatin receptors / γ-Aminobutyric acid B receptors