title: Light-potentiation of acoustic startle response (ASR) and monoamine efflux related to fearfulness in Fyn-deficient mice.
abstract: Fyn tyrosine kinase deficient mice are known to show increased fearfulness. We investigated the fear response of these mice using the light-potentiation of the acoustic startle response (ASR) and examined its neurochemical correlates using in vivo microdialysis. Female homozygous Fyn-deficient mice showed an enhancement of the startle amplitude under a bright light while heterozygotes and wild-types did not show such a change. Along with these behavioral findings, the homozygous Fyn-deficient mice showed an increase in extracellular serotonin (5-HT) and dopamine (DA) in the prefrontal cortex and 5-HT in the hippocampus when they were exposed to bright light, while heterozygous and wild-type mice did not show such changes. These results suggest that the increased fearfulness of Fyn-deficient mice is related to enhanced serotonergic and dopaminergic activity in the prefrontal cortex and limbic system.
authors.affiliation: Laboratory for Neurobiology of Emotion, Brain Science Institute RIKEN, 2-1 Hirosawa, Wako-shi, 351-0198, Saitama-ken, Japan. hironaka@psy.senshu-u.ac.jp
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hironaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yagi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Niki
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000201:enzymology / Q000502:physiology*; D003433:Crosses, Genetic; D003624:Darkness; D004298:Dopamine / Q000378:metabolism*; D005239:Fear / Q000502:physiology*; D005260:Female; D005838:Genotype; D006624:Hippocampus / Q000201:enzymology / Q000502:physiology*; D008027:Light; D008032:Limbic System / Q000201:enzymology / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D017551:Microdialysis; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D017397:Prefrontal Cortex / Q000201:enzymology / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051076:Proto-Oncogene Proteins c-fyn; D013216:Reflex, Startle / Q000528:radiation effects*; D012701:Serotonin / Q000378:metabolism*
chemical_list: D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D012701:Serotonin; C494960:Fyn protein, mouse; D051076:Proto-Oncogene Proteins c-fyn; D004298:Dopamine