Effects of synaptic activity on dendritic spine motility of developing cortical layer v pyramidal neurons.
It is increasingly clear that dendritic spines play an important role in compartmentalizing post-synaptic signals and that their dynamic morphological properties have functional consequences. Here, we examine this issue using two-photon microscopy to characterize spine motility on layer V pyramidal neurons in acute slices of the developing mouse cortex. In this system, all spine classes except filopodia become less dynamic as development proceeds. General manipulations of activity (TTX or KCl treatment) do not alter spine dynamics, although increased glutamatergic transmission (AMPA or NMDA treatment) stabilizes developing cortical spines. These effects on spine dynamics do not appear to be related to AMPA or NMDA receptor expression as assessed with immunolabeling, as there is no correlation between spine motility and AMPA (GluR1/2) or NMDA (NR1/NR2B) receptor subunit expression on a spine by spine basis. These results indicate that activity through glutamatergic synapses is important for regulating spine motility in the developing mouse cortex, and that the relative complement of receptors, while different across morphological classifications, cannot account for differences in dynamic structural changes in dendritic spines.
Oray
Serkan
S
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Majewska
Ania
A
Sur
Mriganka
M
D000199:Actins / Q000378:metabolism; D000375:Aging / Q000502:physiology; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D003712:Dendrites / Q000502:physiology*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D016202:N-Methylaspartate / Q000494:pharmacology; D009415:Nerve Net / Q000166:cytology / Q000502:physiology; D010446:Peptide Fragments / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology*; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
D000199:Actins; D000779:Anesthetics, Local; D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate; D010446:Peptide Fragments; D011189:Potassium Chloride; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D013779:Tetrodotoxin; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; C409466:NR1 NMDA receptor; C485096:NR2B protein (1292-1308); C104722:glutamate receptor ionotropic, AMPA 2