Neto Auxiliary Subunits Regulate Interneuron Somatodendritic and Presynaptic Kainate Receptors to Control Network Inhibition

Publication date: 29 August 2017
Source:Cell Reports, Volume 20, Issue 9
Author(s): Megan S. Wyeth, Kenneth A. Pelkey, Xiaoqing Yuan, Geoffrey Vargish, April D. Johnston, Steven Hunt, Calvin Fang, Daniel Abebe, Vivek Mahadevan, André Fisahn, Michael W. Salter, Roderick R. McInnes, Ramesh Chittajallu, Chris J. McBain
Although Netos are considered auxiliary subunits critical for kainate receptor (KAR) function, direct evidence for their regulation of native KARs is limited. Because Neto KAR regulation is GluK subunit/Neto isoform specific, such regulation must be determined in cell-type-specific contexts. We demonstrate Neto1/2 expression in somatostatin (SOM)-, cholecystokinin/cannabinoid receptor 1 (CCK/CB1)-, and parvalbumin (PV)-containing interneurons. KAR-mediated excitation of these interneurons is contingent upon Neto1 because kainate yields comparable effects in Neto2 knockouts and wild-types but fails to excite interneurons or recruit inhibition in Neto1 knockouts. In contrast, presynaptic KARs in CCK/CB1 interneurons are dually regulated by both Neto1 and Neto2. Neto association promotes tonic presynaptic KAR activation, dampening CCK/CB1 interneuron output, and loss of this brake in Neto mutants profoundly increases CCK/CB1 interneuron-mediated inhibition. Our results confirm that Neto1 regulates endogenous somatodendritic KARs in diverse interneurons and demonstrate Neto regulation of presynaptic KARs in mature inhibitory presynaptic terminals.

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Teaser

Netos are considered critical kainate receptor (KAR) auxiliary subunits in glutamatergic principal cells, but their roles in GABAergic interneurons remain unexplored. Wyeth et al. find that somatodendritic KARs within diverse interneurons require Neto1, whereas both Neto1 and Neto2 regulate presynaptic KAR-mediated suppression of inhibitory transmission.


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