Formation of dendritic spines in cultured striatal neurons depends on excitatory afferent activity.
The role of afferent innervation in the formation of dendritic spines was studied in cultured rat striatum. The striatum is a unique structure in that it contains highly spiny GABAergic projection neurons, with no known local excitation. Grown alone in culture, striatal neurons did not express spontaneous network activity and were virtually devoid of dendritic spines. Adding GFP-expressing mouse cortical neurons to the striatal culture caused the appearance of spontaneous and evoked excitatory synaptic currents in the striatal neurons and a 10-fold increase in the density of spines on their dendrites. This effect was blocked by a continuous presence of TTX in the growth medium, while removal of the drug caused a rapid appearance of spines. Exposure to glutamate, or the presence of cortex-conditioned medium did not mimic the effect of cortical neurons on formation of spines in the striatal neurons. Also, the cortical innervation did not cause a selective enhancement of survival of specific subtypes of spiny striatal neurons. These experiments demonstrate that excitatory afferents are necessary for the formation of dendritic spines in striatal neurons.
Segal
Menahem
M
Department of Neurobiology, The Weizmann Institute, Rehovot 76100, Israel. menahem.segal@weizmann.ac.il
Greenberger
Varda
V
Korkotian
Eduard
E
D000344:Afferent Pathways / Q000502:physiology*; D000596:Amino Acids / Q000378:metabolism; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002452:Cell Count; D048429:Cell Size; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D018920:Coculture Techniques / Q000379:methods; D003342:Corpus Striatum / Q000166:cytology* / Q000187:drug effects; D003952:Diagnostic Imaging; D004558:Electric Stimulation; D004594:Electrophysiology; D004622:Embryo, Mammalian; D004744:Enkephalin, Methionine / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods / Q000706:statistics & numerical data; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D013373:Substance P / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors; D014162:Transfection
D000596:Amino Acids; D000779:Anesthetics, Local; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D008164:Luminescent Proteins; D011810:Quinoxalines; C098463:dolaisoleucine; D049452:Green Fluorescent Proteins; D013373:Substance P; D018698:Glutamic Acid; D013779:Tetrodotoxin; D004744:Enkephalin, Methionine; C056723:FG 9041; D001640:Bicuculline