TY - JOUR
T1 - "Small axonless neurons"
T2 - postnatally generated neocortical interneurons with delayed functional maturation
AU - Le Magueresse, Corentin
AU - Alfonso, Julieta
AU - Khodosevich, Konstantin
AU - Arroyo Martín, Angel A
AU - Bark, Christine
AU - Monyer, Hannah
PY - 2011/11/16
Y1 - 2011/11/16
N2 - GABAergic interneurons of the mouse cortex are generated embryonically in the ventral telencephalon. Recent evidence, however, indicated that a subset of cortical cells expressing interneuronal markers originate in the neonatal subventricular zone. This has raised interest in the functional development and incorporation of these postnatally generated cells into cortical circuits. Here we demonstrate that these cells integrate in the cortex, and that they constitute two distinct GABAergic interneuronal classes. Whereas one class reflects the tail end of embryonic interneuron genesis, the other class comprises interneurons that are exclusively generated perinatally and postnatally. The latter constitute a novel subclass of interneurons. They are preferentially located in the deeper layers of the olfactory and orbital cortices, exhibit a unique firing pattern and slow functional maturation. Based on their distinct morphology we termed them "small axonless neurons" and indeed, unlike other cortical neurons, they communicate with their neuronal partners via dendrodendritic synapses. Finally, we provide evidence that the number of small axonless neurons is enhanced by odor enrichment, a further indication that they integrate into neural circuits and participate to olfactory processing.
AB - GABAergic interneurons of the mouse cortex are generated embryonically in the ventral telencephalon. Recent evidence, however, indicated that a subset of cortical cells expressing interneuronal markers originate in the neonatal subventricular zone. This has raised interest in the functional development and incorporation of these postnatally generated cells into cortical circuits. Here we demonstrate that these cells integrate in the cortex, and that they constitute two distinct GABAergic interneuronal classes. Whereas one class reflects the tail end of embryonic interneuron genesis, the other class comprises interneurons that are exclusively generated perinatally and postnatally. The latter constitute a novel subclass of interneurons. They are preferentially located in the deeper layers of the olfactory and orbital cortices, exhibit a unique firing pattern and slow functional maturation. Based on their distinct morphology we termed them "small axonless neurons" and indeed, unlike other cortical neurons, they communicate with their neuronal partners via dendrodendritic synapses. Finally, we provide evidence that the number of small axonless neurons is enhanced by odor enrichment, a further indication that they integrate into neural circuits and participate to olfactory processing.
KW - 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology
KW - Age Factors
KW - Animals
KW - Animals, Newborn
KW - Bromodeoxyuridine/metabolism
KW - Cell Count
KW - Cell Movement/genetics
KW - Cell Transplantation
KW - Electric Stimulation
KW - Embryo, Mammalian
KW - Excitatory Amino Acid Antagonists/pharmacology
KW - Excitatory Postsynaptic Potentials/drug effects
KW - Gene Expression Regulation, Developmental/drug effects
KW - Glutamate Decarboxylase/metabolism
KW - Green Fluorescent Proteins/genetics
KW - Humans
KW - In Vitro Techniques
KW - Inhibitory Postsynaptic Potentials/drug effects
KW - Interneurons/classification
KW - Luminescent Proteins/genetics
KW - Mice
KW - Mice, Inbred C57BL
KW - Mice, Transgenic
KW - Microscopy, Confocal
KW - Microscopy, Immunoelectron
KW - Microtubule-Associated Proteins/metabolism
KW - Neocortex/cytology
KW - Odorants
KW - Olfactory Pathways/cytology
KW - Patch-Clamp Techniques
KW - Receptors, Serotonin/genetics
KW - Time Factors
KW - Transfection/methods
KW - Vesicular Inhibitory Amino Acid Transport Proteins/metabolism
KW - Wheat Germ Agglutinins/genetics
KW - gamma-Aminobutyric Acid/pharmacology
U2 - 10.1523/jneurosci.4273-11.2011
DO - 10.1523/jneurosci.4273-11.2011
M3 - Journal article
C2 - 22090500
SN - 0270-6474
VL - 31
SP - 16731
EP - 16747
JO - The Journal of neuroscience : the official journal of the Society for Neuroscience
JF - The Journal of neuroscience : the official journal of the Society for Neuroscience
IS - 46
ER -