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Abnormalities in cortical interneuron subtypes in ephrin‐B mutant mice
Author(s) -
Talebian Asghar,
Britton Rachel,
Henkemeyer Mark
Publication year - 2018
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.14022
Subject(s) - parvalbumin , interneuron , calretinin , glutamate decarboxylase , biology , neocortex , neuroscience , population , hippocampal formation , inhibitory postsynaptic potential , hippocampus , cortex (anatomy) , microbiology and biotechnology , immunohistochemistry , immunology , biochemistry , demography , sociology , enzyme
To explore roles for ephrin‐B/EphB signaling in cortical interneurons, we previously generated ephrin‐B ( Efnb1/b2/b3 ) conditional triple mutant ( TM lz ) mice using a Dlx1/2.Cre inhibitory neuron driver and green fluorescent protein ( GFP ) reporters for the two main inhibitory interneuron groups distinguished by expression of either glutamic acid decarboxylase 1 ( GAD 1; GAD 67‐ GFP ) or 2 ( GAD 2; GAD 65‐ GFP ). This work showed a general involvement of ephrin‐B in migration and population of interneurons into the embryonic neocortex. We now determined whether specific interneurons are selectively affected in the adult brains of TM lz .Cre mice by immunostaining with antibodies that identify the different subtypes. The results indicate that GAD 67‐ GFP ‐expressing interneurons that also express parvalbumin ( PV ), calretinin ( CR ) and, to a lesser extent, somatostatin ( SST ) and Reelin (Rln) were significantly reduced in the cortex and hippocampal CA 1 region in TM lz .Cre mutant mice. Neuropeptide Y ( NPY ) interneurons that also express GAD 67‐ GFP were reduced in the hippocampal CA 1 region, but much less so in the cortex, although these cells exhibited abnormal cortical layering. In GAD 65‐ GFP ‐expressing interneurons, CR subtypes were reduced in both cortex and hippocampal CA 1 region, whereas Rln interneurons were reduced exclusively in hippocampus, and the numbers of NPY and vasoactive intestinal polypeptide ( VIP ) subtypes appeared normal. PV and CR subtype interneurons in TM lz .Cre mice also exhibited reductions in their perisomatic area, suggesting abnormalities in dendritic/axonal complexity. Altogether, our data indicate that ephrin‐B expression within forebrain interneurons is required in specific subtypes for their normal population, cortical layering and elaboration of cell processes.