title: A role of actin filament in synaptic transmission and long-term potentiation.
abstract: The role of actin filaments in synaptic function has been studied in the CA1 region of the rat hippocampal slice. Bath application (2 hr) of the actin polymerization inhibitor latrunculin B did not substantially affect the shape of dendrites or spines. However, this and other drugs that affect actin did affect synaptic function. Bath-applied latrunculin B reduced the synaptic response. Several lines of evidence indicate that a component of this effect is presynaptic. To specifically test for a postsynaptic role for actin, latrunculin B or phalloidin, an actin filament stabilizer, was perfused into the postsynaptic neuron. The magnitude of long-term potentiation (LTP) was decreased at times when baseline transmission was not yet affected. Longer applications produced a decrease in baseline AMPA receptor (AMPAR)-mediated transmission. The magnitude of the NMDA receptor-mediated transmission was unaffected, indicating a specific effect on the AMPAR. These results suggest that postsynaptic actin filaments are involved in a dynamic process required to maintain AMPAR-mediated transmission and to enhance it during LTP.
authors.affiliation: Department of Neuroscience and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: C H
authors.initials: CH
authors.lastname: Kim
authors.forename: J E
authors.initials: JE
authors.lastname: Lisman
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D010590:Phalloidine / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D051381:Rats; D020318:Rats, Long-Evans; D009435:Synaptic Transmission / Q000502:physiology*; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines
chemical_list: D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D011500:Protein Synthesis Inhibitors; D013844:Thiazoles; D053778:Thiazolidines; D010590:Phalloidine; D015638:Cytochalasin D; C037068:latrunculin B