Impaired dendritic spine maturation in GABAA receptor alpha1 subunit knock out mice.
In this study we investigated the functional implications of GABAA receptor alpha1 subunit deletion on dendritic arborization and spine maturation in the visual cortex. This subunit is normally strongly upregulated during early postnatal development. Our main finding is that mice lacking the GABAA receptor alpha1 subunit displayed an increased density of dendritic filopodia during the second and third postnatal weeks. However, there was a concomitant decreased density of mature mushroom-shaped spines, which became more pronounced in adults. In contrast, dendritic arborization was not altered in these mice. We propose that an increased efficacy of the inhibitory synaptic transmission in the alpha1 knock out mice may lead to an enhancement of the outgrowth of filopodia around eye opening, but to a failure in spine maturation at later stages.
Heinen
K
K
Department of Experimental Neurophysiology, Research Institute Neurosciences, Faculty of Earth and Life Sciences and Centre for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, de Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
Baker
R E
RE
Spijker
S
S
Rosahl
T
T
van Pelt
J
J
Brussaard
A B
AB
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism; D003712:Dendrites / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism*; D017966:Pyramidal Cells / Q000254:growth & development / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D011963:Receptors, GABA-A / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016622:Silver Staining / Q000379:methods; D014793:Visual Cortex / Q000254:growth & development / Q000378:metabolism / Q000473:pathology*
D019208:Brain-Derived Neurotrophic Factor; D009419:Nerve Tissue Proteins; D021122:Protein Subunits; D012333:RNA, Messenger; D011963:Receptors, GABA-A; C033652:postsynaptic density proteins