Functional plasticity triggers formation and pruning of dendritic spines in cultured hippocampal networks.
Despite widespread interest in dendritic spines, little is known about the mechanisms responsible for spine formation, retraction, or stabilization. We have now found that a brief exposure of cultured hippocampal neurons to a conditioning medium that favors activation of the NMDA receptor produces long-term modification of their spontaneous network activity. The conditioning protocol enhances correlated activity of neurons in the culture, in a process requiring an increase in [Ca(2+)](i) and is associated with both formation of novel dendritic spines and pruning of others. The novel spines are likely to be touched by a presynaptic terminal, labeled with FM4-64 dye, whereas the absence of such terminals increases the likelihood of spine pruning. These results indicate that long-term functional changes are correlated with morphological modifications of dendritic spines of neurons in a network.
Goldin
M
M
Department of Neurobiology, The Weizmann Institute, Rehovot 76100, Israel.
Segal
M
M
Avignone
E
E
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D005456:Fluorescent Dyes; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009415:Nerve Net / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013569:Synapses / Q000378:metabolism / Q000648:ultrastructure
D017077:Culture Media, Conditioned; D018691:Excitatory Amino Acid Antagonists; C092350:FM 4-64; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D016194:Receptors, N-Methyl-D-Aspartate; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D015763:2-Amino-5-phosphonovalerate