Somatostatin and parvalbumin inhibitory synapses onto hippocampal pyramidal neurons are regulated by distinct mechanisms
Excitation–inhibition balance is critical for optimal brain function, yet the mechanisms underlying the tuning of inhibition from different populations of inhibitory neurons are unclear. Here, we found evidence for two distinct pathways through which excitatory neurons cell-autonomously modulate inh...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 115; no. 3; pp. 589 - 594 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
16.01.2018
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Subjects | |
Online Access | Get full text |
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Summary: | Excitation–inhibition balance is critical for optimal brain function, yet the mechanisms underlying the tuning of inhibition from different populations of inhibitory neurons are unclear. Here, we found evidence for two distinct pathways through which excitatory neurons cell-autonomously modulate inhibitory synapses. Synapses from parvalbumin-expressing interneurons onto hippocampal pyramidal neurons are regulated by neuronal firing, signaling through L-type calcium channels. Synapses from somatostatin-expressing interneurons are regulated by NMDA receptors, signaling through R-type calcium channels. Thus, excitatory neurons can cell-autonomously regulate their inhibition onto different subcellular compartments through their input (glutamatergic signaling) and their output (firing). Separately, while somatostatin and parvalbumin synapses onto excitatory neurons are both dependent on a common set of post-synaptic proteins, including gephyrin, collybistin, and neuroligin-2, decreasing neuroligin-3 expression selectively decreases inhibition from somatostatin interneurons, and overexpression of neuroligin-3 selectively enhances somatostatin inhibition. These results provide evidence that excitatory neurons can selectively regulate two distinct sets of inhibitory synapses. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewers: C.G., Novartis Institutes for BioMedical Research; and I.S., Stanford University. Contributed by Roger A. Nicoll, December 7, 2017 (sent for review November 8, 2017; reviewed by Carleton Goold and Ivan Soltesz) Author contributions: M.E.H. and R.A.N. designed research; M.E.H. performed research; M.E.H. contributed new reagents/analytic tools; M.E.H. and R.A.N. analyzed data; and M.E.H. wrote the paper. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.1719523115 |