Ontogenic changes of the GABAergic system in the embryonic mouse spinal

Anne-Emilie Allain, Alexia Baı̈ri, Pierre Meyrand, Pascal Branchereau
Brain Research. 2004-03-01; 1000(1-2): 134-147
DOI: 10.1016/j.brainres.2003.11.071

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1. Brain Res. 2004 Mar 12;1000(1-2):134-47.

Ontogenic changes of the GABAergic system in the embryonic mouse spinal cord.

Allain AE(1), Baïri A, Meyrand P, Branchereau P.

Author information:
(1)Laboratoire de Neurobiologie des Réseaux, Université Bordeaux 1 et Centre
National de la Recherche Scientifique, Unité Mixte de Recherche 5816, Avenue des
Facultés, 33405 Talence, France.

Numerous studies have demonstrated an excitatory action of GABA early in
development, which is likely to play a neurotrophic role. In order to better
understand the role of GABA in the mouse spinal cord, we followed the evolution
of GABAergic neurons over the course of development. We investigated, in the
present study, the ontogeny of GABA immunoreactive (GABA-ir) cell bodies and
fibers in the embryonic mouse spinal cord at brachial and lumbar levels. GABA-ir
somata were first detected at embryonic day 11.5 (E11.5) exclusively at brachial
level in the marginal zone. By E13.5, the number of GABAergic neurons sharply
increased throughout the extent of the ventral horn both at brachial and lumbar
level. Stained perikarya first appeared in the future dorsal horn at E15.5 and
progressively invaded this area while they decreased in number in the presumed
ventral gray matter. At E12.5, E13.5 and E15.5, we checked the possibility that
ventral GABA-ir cells could belong to the motoneuronal population. Using a
GABA/Islet-1/2 double labeling, we did not detect any double-stained neurons
indicating that spinal motoneurons do not synthesize GABA during the course of
development. GABA-ir fibers also appeared at the E11.5 stage in the presumptive
lateral white matter at brachial level. At E12.5 and E13.5, GABA-ir fibers
progressively invaded the ventral marginal zone and by E15.5 reached the dorsal
marginal zone. At E17.5 and postnatal day 0 (P0), the number of GABA-ir fibers
declined in the white matter. Finally, by P0, GABA immunoreactivity that
delineated somata was mainly restricted to the dorsal gray matter and declined in
intensity and extent. The ventral gray matter exhibited very few GABA-ir cell
bodies at this neonatal stage of development. The significance of the migration
of somatic GABA immunoreactivity from ventral to the dorsal gray matter is

DOI: 10.1016/j.brainres.2003.11.071
PMID: 15053961 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus