title: Entorhinal denervation induces homeostatic synaptic scaling of excitatory postsynapses of dentate granule cells in mouse organotypic slice cultures.
abstract: Denervation-induced changes in excitatory synaptic strength were studied following entorhinal deafferentation of hippocampal granule cells in mature (≥ 3 weeks old) mouse organotypic entorhino-hippocampal slice cultures. Whole-cell patch-clamp recordings revealed an increase in excitatory synaptic strength in response to denervation during the first week after denervation. By the end of the second week synaptic strength had returned to baseline. Because these adaptations occurred in response to the loss of excitatory afferents, they appeared to be in line with a homeostatic adjustment of excitatory synaptic strength. To test whether denervation-induced changes in synaptic strength exploit similar mechanisms as homeostatic synaptic scaling following pharmacological activity blockade, we treated denervated cultures at 2 days post lesion for 2 days with tetrodotoxin. In these cultures, the effects of denervation and activity blockade were not additive, suggesting that similar mechanisms are involved. Finally, we investigated whether entorhinal denervation, which removes afferents from the distal dendrites of granule cells while leaving the associational afferents to the proximal dendrites of granule cells intact, results in a global or a local up-scaling of granule cell synapses. By using computational modeling and local electrical stimulations in Strontium (Sr(2+))-containing bath solution, we found evidence for a lamina-specific increase in excitatory synaptic strength in the denervated outer molecular layer at 3-4 days post lesion. Taken together, our data show that entorhinal denervation results in homeostatic functional changes of excitatory postsynapses of denervated dentate granule cells in vitro.
authors.affiliation: Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany. a.vlachos@med.uni-frankfurt.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Vlachos
authors.forename: Denise
authors.initials: D
authors.lastname: Becker
authors.forename: Peter
authors.initials: P
authors.lastname: Jedlicka
authors.forename: Raphael
authors.initials: R
authors.lastname: Winkels
authors.forename: Jochen
authors.initials: J
authors.lastname: Roeper
authors.forename: Thomas
authors.initials: T
authors.lastname: Deller
mesh_terms: D000818:Animals; D003714:Denervation / Q000009:adverse effects*; D018891:Dentate Gyrus / Q000166:cytology* / Q000473:pathology / Q000502:physiology / Q000503:physiopathology; D004558:Electric Stimulation; D018728:Entorhinal Cortex / Q000187:drug effects / Q000601:surgery*; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D005260:Female; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009422:Nervous System Diseases / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D026941:Sodium Channel Blockers; D013779:Tetrodotoxin