title: Reversible loss of dendritic spines and altered excitability after chronic epilepsy in hippocampal slice cultures.
abstract: The morphological and functional consequences of epileptic activity were investigated by applying the convulsants bicuculline and/or picrotoxin to mature rat hippocampal slice cultures. After 3 days, some cells in all hippocampal subfields showed signs of degeneration, including swollen somata, vacuolation, and dendritic deformities, whereas others displayed only a massive reduction in the number of their dendritic spines. Intracellular recordings from CA3 pyramidal cells revealed a decrease in the amplitude of evoked excitatory synaptic potentials. gamma-Aminobutyric acid-releasing interneurons and inhibitory synaptic potentials were unaffected. Seven days after withdrawal of convulsants, remaining cells possessed a normal number of dendritic spines, thus demonstrating a considerable capacity for recovery. The pathological changes induced by convulsants are similar to those found in the hippocampi of human epileptics, suggesting that they are a consequence, rather than a cause, of epilepsy.
authors.affiliation: Brain Research Institute, University of Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.forename: B H
authors.initials: BH
authors.lastname: Gähwiler
authors.forename: L
authors.initials: L
authors.lastname: Rietschin
authors.forename: S M
authors.initials: SM
authors.lastname: Thompson
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D003712:Dendrites / Q000502:physiology / Q000648:ultrastructure*; D004558:Electric Stimulation; D004827:Epilepsy / Q000473:pathology* / Q000503:physiopathology*; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000473:pathology* / Q000502:physiology / Q000503:physiopathology*; D008564:Membrane Potentials; D009924:Organ Culture Techniques; D009943:Organophosphorus Compounds / Q000494:pharmacology; D011712:Pyramidal Tracts / Q000473:pathology* / Q000503:physiopathology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D013569:Synapses / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D009943:Organophosphorus Compounds; D011810:Quinoxalines; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate; C066430:CGP 35348; C006749:bicuculline methochloride; D001640:Bicuculline