Common origins of hippocampal Ivy and nitric oxide synthase expressing neurogliaform cells.
GABAergic interneurons critically regulate cortical computation through exquisite spatiotemporal control over excitatory networks. Precision of this inhibitory control requires a remarkable diversity within interneuron populations that is largely specified during embryogenesis. Although interneurons expressing the neuronal isoform of nitric oxide synthase (nNOS) constitute the largest hippocampal interneuron cohort their origin and specification remain unknown. Thus, as neurogliaform cells (NGC) and Ivy cells (IvC) represent the main nNOS(+) interneurons, we investigated their developmental origins. Although considered distinct interneuron subtypes, NGCs and IvCs exhibited similar neurochemical and electrophysiological signatures, including NPY expression and late spiking. Moreover, lineage analyses, including loss-of-function experiments and inducible fate-mapping, indicated that nNOS(+) IvCs and NGCs are both derived from medial ganglionic eminence (MGE) progenitors under control of the transcription factor Nkx2-1. Surprisingly, a subset of NGCs lacking nNOS arises from caudal ganglionic eminence (CGE) progenitors. Thus, while nNOS(+) NGCs and IvCs arise from MGE progenitors, a CGE origin distinguishes a discrete population of nNOS(-) NGCs.
Laboratory of Cellular and Synaptic Neurophysiology, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Ludovic
L
Tricoire
Kenneth A
KA
Pelkey
Michael I
MI
Daw
Vitor H
VH
Sousa
Goichi
G
Miyoshi
Brian
B
Jeffries
Bruno
B
Cauli
Gord
G
Fishell
Chris J
CJ
McBain
D000200:Action Potentials; D000818:Animals; D019070:Cell Lineage; D016764:Cell Polarity; D006624:Hippocampus / Q000166:cytology* / Q000201:enzymology; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology* / Q000201:enzymology / Q000502:physiology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009478:Neuropeptide Y / Q000096:biosynthesis; D052248:Nitric Oxide Synthase Type I / Q000096:biosynthesis*; D009687:Nuclear Proteins / Q000502:physiology; D018408:Patch-Clamp Techniques; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D013687:Telencephalon / Q000166:cytology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000502:physiology; D014660:Vasoactive Intestinal Peptide / Q000096:biosynthesis
D009478:Neuropeptide Y; C000614414:Nkx2-1 protein, mouse; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D014660:Vasoactive Intestinal Peptide; D052248:Nitric Oxide Synthase Type I