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Single‐cell RNA‐Seq characterization of anatomically identified OLM interneurons in different transgenic mouse lines
Author(s) -
Winterer Jochen,
Lukacsovich David,
Que Lin,
Sartori Andrea M.,
Luo Wenshu,
Földy Csaba
Publication year - 2019
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.14549
Subject(s) - biology , population , gene isoform , neuroscience , gene , genetics , demography , sociology
Inhibitory GABA ergic interneurons create different brain activity patterns that correlate with behavioural states. In this characterizing study, we used single‐cell RNA‐Seq to analyse anatomically‐ and electrophysiologically identified hippocampal oriens‐lacunosum moleculare ( OLM ) interneurons. OLM s express somatostatin (Sst), generate feedback inhibition and play important roles in theta oscillations and fear encoding. Although an anatomically‐ and biophysically homogenous population, OLMs presumably comprise of two functionally distinct types with different developmental origins, inferred from the expression pattern of serotonin type‐3a (5‐ HT 3a, or Htr3a ) receptor subunit and 5‐ HT excitability in a set of OLM s. To broadly characterize OLM cells, we used the Sst‐Cre and the BAC transgenic Htr3a‐Cre mouse lines and separately analysed SstCre‐ OLM and Htr3aCre‐ OLM types. We found a surprisingly consistent expression of Npy in OLM s, which was previously not associated with the identity of this type. Our analyses furthermore revealed uniform expression of developmental origin‐related genes, including transcription factors and neurexin isoforms, without providing support for the current view that OLM s may originate from multiple neurogenic zones. Together, we found that OLM s constitute a highly homogenous transcriptomic population. Finally, our results revealed surprisingly infrequent expression of Htr3a in only ~10% of OLM s and an apparently specific expression of the 5‐ HT 3b subunit‐coding gene Htr3b in Htr3aCre‐ OLM s, but not in SstCre‐ OLM s. However, additional in situ hybridization experiments suggested that the differential expression of Htr3b may represent an unexpected consequence arising from the design of the Htr3a‐Cre BAC transgenic line.