title: Role of the somatostatin system in contextual fear memory and hippocampal synaptic plasticity.
abstract: Somatostatin has been implicated in various cognitive and emotional functions, but its precise role is still poorly understood. Here, we have made use of mice with somatostatin deficiency, based upon genetic invalidation or pharmacologically induced depletion, and Pavlovian fear conditioning in order to address the contribution of the somatostatin system to associative fear memory. The results demonstrate an impairment of foreground and background contextual but not tone fear conditioning in mice with targeted ablation of the somatostatin gene. These deficits were associated with a decrease in long-term potentiation in the CA1 area of the hippocampus. Both the behavioral and the electrophysiological phenotypes were mimicked in wild-type mice through application of the somatostatin-depleting substance cysteamine prior to fear training, whereas no further deficits were observed upon application in the somatostatin null mutants. These results suggest that the somatostatin system plays a critical role in the acquisition of contextual fear memory, but not tone fear learning, and further highlights the role of hippocampal synaptic plasticity for information processing concerning contextual information.
authors.affiliation: Institute of Physiology I (Neurophysiology), Westfälische Wilhelms-University Münster, 48149 Münster, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kluge
authors.forename: Christian
authors.initials: C
authors.lastname: Stoppel
authors.forename: Csaba
authors.initials: C
authors.lastname: Szinyei
authors.forename: Oliver
authors.initials: O
authors.lastname: Stork
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Pape
mesh_terms: D000818:Animals; D001244:Association; D003213:Conditioning, Psychological; D003463:Cues; D003543:Cysteamine / Q000008:administration & dosage / Q000494:pharmacology; D004334:Drug Administration Schedule; D004594:Electrophysiology / Q000295:instrumentation; D005239:Fear / Q000502:physiology*; D006624:Hippocampus / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D051379:Mice; D009473:Neuronal Plasticity / Q000502:physiology*; D010641:Phenotype; D011187:Posture; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000494:pharmacology; D013004:Somatostatin / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D011837:Radiation-Protective Agents; D013004:Somatostatin; D003543:Cysteamine