title: Altered behaviour in hamsters conceived and born in hypergravity.
abstract: We studied vestibular function in 37 hamsters (1 month old) conceived and born in either hypergravity (n = 21) or normal gravity (n = 16). Four groups were made: (1) HL group: 20 weeks in 2.5 G and 14 weeks in 1 G; (2) HS group: 4 weeks in 2.5 G and 30 weeks in 1 G; (3) CON group: 34 weeks in 1 G; and (4) ROT group: 4 weeks in 1 G, 16 weeks in rotation in 1 G, at the centre of the centrifuge and 14 weeks 1 G. When the hamsters were 4 weeks old, their locomotor activity, swimming ability, and air-righting was assessed. We found that HL and HS hamsters had no disturbances during locomotion in 1 G but their swimming ability was disturbed (swimming underwater, circling, and decreased speed of swimming). The HL hamsters showed less activity during 2.5 G and showed fewer correct air-rightings than the other groups. Differences between groups in swimming ability and the number of correct air-righting responses remained even after 3 months of normal gravity. Based on these findings, we suggest that the persistent behavioural disturbances are caused by the embryonal development of the hamsters in a hypergravity environment. Furthermore, hypergravity and rotation each have a different effect on behaviour.
authors.affiliation: Vestibular Department ENT, University of Amsterdam, The Netherlands.
authors.forename: H N
authors.initials: HN
authors.lastname: Sondag
authors.forename: H A
authors.initials: HA
authors.lastname: de Jong
authors.forename: W J
authors.initials: WJ
authors.lastname: Oosterveld
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D006224:Cricetinae; D018471:Hypergravity; D008124:Locomotion / Q000502:physiology*; D013647:Task Performance and Analysis; D014726:Vestibular Nuclei / Q000502:physiology*