title: Learned fear, emotional reactivity and fear of heights: a factor analytic map from a large F(2) intercross of Roman rat strains.
abstract: Anxiety-related behaviours were evaluated across various tests in a 800 F(2)-intercross of the Roman high- and low-avoidance inbred rats. These tests either evoke unlearned (open field [OF]; plus-maze [PM]; hole-board [HB]; spontaneous activity [A]; and acoustic startle reflex [ASR]) or learned (classical fear conditioning [CFC]; and shuttlebox avoidance conditioning [SAC]), anxious/fearful responses. Using factor analysis (oblique rotation), we obtained a six-fold solution with 14 variables derived from all tests. These six factors represented SAC, CFC, PM anxiety, PM and OF activity, ASR anxiety, plus a mixed whole of anxious and activity variables (from OF and A), respectively. In searching for a smaller number of meaningful factors, we applied a three-factor solution that coherently corresponded with differentiated facets of fearfulness, rather than with the tests. Results showed that (1) measures of SAC and CFC strongly loaded onto Factor 1, labelled as "Learned Fear"; (2) a blend of almost all variables loaded onto Factor 2, called "Emotional Reactivity"; and (3) open arm behaviour in the PM loaded onto Factor 3, called "Fear of Heights." After discussing limitations of this apparently consistent behavioural map of anxiety, we advance some connections between those factors with quantitative trait loci candidates (genetic markers) as detected in the same sample.
authors.affiliation: Medical Psychology Unit, Department of Psychiatry and Forensic Medicine, School of Medicine, Autonomous University of Barcelona, Barcelona, Spain. raul.aguilar@uab.es
authors.forename: Raúl
authors.initials: R
authors.lastname: Aguilar
authors.forename: Luis
authors.initials: L
authors.lastname: Gil
authors.forename: Jonathan
authors.initials: J
authors.lastname: Flint
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Gray
authors.forename: Gerard R
authors.initials: GR
authors.lastname: Dawson
authors.forename: Peter
authors.initials: P
authors.lastname: Driscoll
authors.forename: Lydia
authors.initials: L
authors.lastname: Giménez-Llort
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Escorihuela
authors.forename: Alberto
authors.initials: A
authors.lastname: Fernández-Teruel
authors.forename: Adolf
authors.initials: A
authors.lastname: Tobeña
mesh_terms: D000818:Animals; D001007:Anxiety / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology; D005163:Factor Analysis, Statistical; D005239:Fear / Q000502:physiology* / Q000523:psychology; D005260:Female; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D009483:Neuropsychological Tests; D051381:Rats; D011919:Rats, Inbred Strains / Q000235:genetics* / Q000502:physiology / Q000523:psychology; D013216:Reflex, Startle / Q000502:physiology