title: Cajal-Retzius cells switch from expressing gamma-less to gamma-containing GABA receptors during corticogenesis.
abstract: Cajal-Retzius cells are implicated in regulating neuronal migration and lamination during corticogenesis. In rodents, Cajal-Retzius cells are transient, being prevalent in the marginal zone of the embryonic neocortex and declining over the first two postnatal weeks. While studies have examined in postnatal neocortex the properties of GABA(A) receptors in Cajal-Retzius cells, less is known about their disposition at embryonic stages. Here, we combined patch-clamp electrophysiology and single-cell mRNA profiling to probe the expression of GABA(A) receptors in Cajal-Retzius cells. In embryonic neocortical slices, GABA elicited GABA(A) receptor-mediated current responses that were diazepam-insensitive and inhibited by Zn(2+), a pharmacological profile consistent with expression of gamma-less GABA(A) receptor isoforms. Non-Cajal-Retzius cells in the same embryonic slices, on the other hand, were robustly potentiated by diazepam and were insensitive to Zn(2+), typical of gamma-containing GABA(A) receptor isoforms, as were Cajal-Retzius cells in the postnatal neocortex. Single-cell mRNA profiling and immunohistochemistry confirmed expression of GABA(A) receptor gamma subunit transcript and protein, respectively, in individual reelin-expressing cells in the postnatal cortex but not in their embryonic counterparts. We conclude that Cajal-Retzius cells express gamma-less GABA(A) receptors at embryonic stages and switch to expressing gamma-containing GABA(A) receptor isoforms during postnatal neocortical development.
authors.affiliation: Department of Physiology, Dartmouth Medical School, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Cheng
authors.forename: Pamela W L
authors.initials: PW
authors.lastname: Yeh
authors.forename: Hermes H
authors.initials: HH
authors.lastname: Yeh
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D015816:Cell Adhesion Molecules, Neuronal / Q000037:antagonists & inhibitors; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D017931:DNA Primers; D003627:Data Interpretation, Statistical; D003975:Diazepam / Q000494:pharmacology; D004594:Electrophysiology; D016326:Extracellular Matrix Proteins / Q000037:antagonists & inhibitors; D005260:Female; D018757:GABA Modulators / Q000494:pharmacology; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011247:Pregnancy; D011963:Receptors, GABA-A / Q000502:physiology*; D000091042:Reelin Protein; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases; D015032:Zinc / Q000494:pharmacology
chemical_list: D019138:Antibodies, Blocking; D015816:Cell Adhesion Molecules, Neuronal; D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D018757:GABA Modulators; D009419:Nerve Tissue Proteins; D011963:Receptors, GABA-A; D000091042:Reelin Protein; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases; D015032:Zinc; D003975:Diazepam