title: Reconstitution of the hippocampal mossy fiber and associational-commissural pathways in a novel dissociated cell culture system.
abstract: Synapses of the hippocampal mossy fiber pathway exhibit several characteristic features, including a unique form of long-term potentiation that does not require activation of the N-methyl-D-aspartate receptor by glutamate, a complex postsynaptic architecture, and sprouting in response to seizures. However, these connections have proven difficult to study in hippocampal slices because of their relative paucity (<0.4%) compared to commissural-collateral synapses. To overcome this problem, we have developed a novel dissociated cell culture system in which we have enriched mossy fiber synapses by increasing the ratio of granule-to-pyramidal cells. As in vivo, mossy fiber connections are composed of large dynorphin A-positive varicosities contacting complex spines (but without a restricted localization). The elementary synaptic connections are glutamatergic, inhibited by dynorphin A, and exhibit N-methyl-D-aspartate-independent long-term potentiation. Thus, the simplicity and experimental accessibility of this enriched in vitro mossy fiber pathway provides a new perspective for studying nonassociative plasticity in the mammalian central nervous system.
authors.affiliation: Howard Hughes Medical Institute, College of Physicians and Surgeons of Columbia University, NY 10032, USA.
authors.forename: D
authors.initials: D
authors.lastname: Baranes
authors.forename: J C
authors.initials: JC
authors.lastname: López-García
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.forename: C H
authors.initials: CH
authors.lastname: Bailey
authors.forename: E R
authors.initials: ER
authors.lastname: Kandel
mesh_terms: D000818:Animals; D002469:Cell Separation; D002478:Cells, Cultured; D004399:Dynorphins / Q000494:pharmacology / Q000502:physiology; D004594:Electrophysiology; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008854:Microscopy, Electron; D016202:N-Methylaspartate / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D013569:Synapses / Q000502:physiology
chemical_list: D016202:N-Methylaspartate; D004399:Dynorphins