title: Neural correlates of sensorimotor gating: a metabolic positron emission tomography study in awake rats.
abstract: Impaired sensorimotor gating occurs in neuropsychiatric disorders such as schizophrenia and can be measured using the prepulse inhibition (PPI) paradigm of the acoustic startle response. This assay is frequently used to validate animal models of neuropsychiatric disorders and to explore the therapeutic potential of new drugs. The underlying neural network of PPI has been extensively studied with invasive methods and genetic modifications. However, its relevance for healthy untreated animals and the functional interplay between startle- and PPI-related areas during a PPI session is so far unknown. Therefore, we studied awake rats in a PPI paradigm, startle control and background noise control, combined with behavioral [(18)F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Subtractive analyses between conditions were used to identify brain regions involved in startle and PPI processing in well-hearing Black hooded rats. For correlative analysis with regard to the amount of PPI we also included hearing-impaired Lister hooded rats that startled more often, because their hearing threshold was just below the lowest prepulses. Metabolic imaging showed that the brain areas proposed for startle and PPI mediation are active during PPI paradigms in healthy untreated rats. More importantly, we show for the first time that the whole PPI modulation network is active during "passive" PPI sessions, where no selective attention to prepulse or startle stimulus is required. We conclude that this reflects ongoing monitoring of stimulus significance and constant adjustment of sensorimotor gating.
authors.affiliation: Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany ; Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Cathrin
authors.initials: C
authors.lastname: Rohleder
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Jung
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Hanna
authors.initials: H
authors.lastname: Mertgens
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wiedermann
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Sué
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Neumaier
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Graf
authors.affiliation: Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany.
authors.forename: F Markus
authors.initials: FM
authors.lastname: Leweke
authors.affiliation: Multimodal Imaging, Max Planck Institute for Neurological Research Cologne, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Endepols
keywords: FDG-PET; glucose utilization; neural network; neuropsychiatric disorders; prepulse inhibition; startle; translational research