Genetic fate mapping reveals that the caudal ganglionic eminence produces a large and diverse population of superficial cortical interneurons.
By combining an inducible genetic fate mapping strategy with electrophysiological analysis, we have systematically characterized the populations of cortical GABAergic interneurons that originate from the caudal ganglionic eminence (CGE). Interestingly, compared with medial ganglionic eminence (MGE)-derived cortical interneuron populations, the initiation [embryonic day 12.5 (E12.5)] and peak production (E16.5) of interneurons from this embryonic structure occurs 3 d later in development. Moreover, unlike either pyramidal cells or MGE-derived cortical interneurons, CGE-derived interneurons do not integrate into the cortex in an inside-out manner but preferentially (75%) occupy superficial cortical layers independent of birthdate. In contrast to previous estimates, CGE-derived interneurons are both considerably greater in number (approximately 30% of all cortical interneurons) and diversity (comprised by at least nine distinct subtypes). Furthermore, we found that a large proportion of CGE-derived interneurons, including the neurogliaform subtype, express the glycoprotein Reelin. In fact, most CGE-derived cortical interneurons express either Reelin or vasoactive intestinal polypeptide. Thus, in conjunction with previous studies, we have now determined the spatial and temporal origins of the vast majority of cortical interneuron subtypes.
Miyoshi
Goichi
G
Smilow Neuroscience Program and the Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.
Hjerling-Leffler
Jens
J
Karayannis
Theofanis
T
Sousa
Vitor H
VH
Butt
Simon J B
SJ
Battiste
James
J
Johnson
Jane E
JE
Machold
Robert P
RP
Fishell
Gord
G
D000818:Animals; D019521:Body Patterning / Q000235:genetics; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics*; D002540:Cerebral Cortex / Q000166:cytology* / Q000196:embryology / Q000378:metabolism / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005819:Genetic Markers; D005821:Genetic Techniques; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D008297:Male; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism; D018408:Patch-Clamp Techniques; D016548:Prosencephalon / Q000166:cytology / Q000502:physiology; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000378:metabolism
D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D005819:Genetic Markers; D009419:Nerve Tissue Proteins; D000091042:Reelin Protein; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases