title: Neural correlates of olfactory and visual memory performance in 3D-simulated mazes after intranasal insulin application.
abstract: This fMRI study intended to establish 3D-simulated mazes with olfactory and visual cues and examine the effect of intranasally applied insulin on memory performance in healthy subjects. The effect of insulin on hippocampus-dependent brain activation was explored using a double-blind and placebo-controlled design. Following intranasal administration of either insulin (40IU) or placebo, 16 male subjects participated in two experimental MRI sessions with olfactory and visual mazes. Each maze included two separate runs. The first was an encoding maze during which subjects learned eight olfactory or eight visual cues at different target locations. The second was a recall maze during which subjects were asked to remember the target cues at spatial locations. For eleven included subjects in the fMRI analysis we were able to validate brain activation for odor perception and visuospatial tasks. However, we did not observe an enhancement of declarative memory performance in our behavioral data or hippocampal activity in response to insulin application in the fMRI analysis. It is therefore possible that intranasal insulin application is sensitive to the methodological variations e.g. timing of task execution and dose of application. Findings from this study suggest that our method of 3D-simulated mazes is feasible for studying neural correlates of olfactory and visual memory performance.
authors: Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen, 52074 Aachen, Germany. Electronic address: ybruenner@ukaachen.de.
authors: Yvonne F
authors: YF
authors: Brünner
authors: Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen, 52074 Aachen, Germany.
authors: Rea
authors: R
authors: Rodriguez-Raecke
authors: Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen, 52074 Aachen, Germany.
authors: Smiljana
authors: S
authors: Mutic
authors: Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden.
authors: Christian
authors: C
authors: Benedict
authors: Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen, 52074 Aachen, Germany; Fraunhofer Institute for Process Engineering and Packaging IVV, 85354 Freising, Germany. Electronic address: jfreiherr@ukaachen.de.
authors: Jessica
authors: J
authors: Freiherr
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D004311:Double-Blind Method; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology*; D065852:Spatial Memory / Q000187:drug effects / Q000502:physiology*; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin
keywords: Hippocampus activation; Intranasal insulin; Olfaction; Spatial memory