Early signs of neurolipidosis-related behavioural alterations in a murine model of metachromatic leukodystrophy.
Arylsulfatase A (ASA)-deficient mice represent an animal model for the lysosomal storage disorder metachromatic leukodystrophy (MLD). Although the model has been applied in pathophysiological and therapeutic studies, the behavioural phenotype of ASA(-/-) mice is only partially characterized, and the most decisive outcome measures for therapy evaluation only emerge beyond 1 year of age. Presently, ASA(-/-) mice and ASA(+/-) control mice were studied at 6 and 12 months of age on an extensive battery including tests of neuromotor ability, exploratory behaviour, and learning and memory. Overt signs of ataxia were not observed in 6-month-old ASA(-/-) mice, but quantitative gait analysis during open-field exploration revealed that ASA(-/-) mice displayed increased hind base width and increased stride lengths for all paws. Their covert motor incoordination was evident in a correlation analysis which unveiled decreased harmonisation of concurrent gait parameters. For example, while ASA(+/-) controls demonstrated substantial convergence of front and hind base width (r=0.54), these variables actually diverged in ASA(-/-) mice (r=-0.37). Furthermore, various behavioural observations indicated emotional alterations in ASA(-/-) mice. Six-month-old ASA(-/-) mice also showed decreased response rates in scheduled operant responding. The present findings could provide relevant behavioural outcome measures for further use of this murine MLD model in preclinical studies.
Stroobants
Stijn
S
Laboratory of Biological Psychology, Department of Psychology, University of Leuven, Leuven, Belgium.
Leroy
Toon
T
Eckhardt
Matthias
M
Aerts
Jean-Marie
JM
Berckmans
Daniel
D
D'Hooge
Rudi
R
D000367:Age Factors; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D002531:Cerebellum / Q000378:metabolism / Q000473:pathology; D002553:Cerebroside-Sulfatase / Q000235:genetics / Q000378:metabolism; D054022:Cerebrum / Q000378:metabolism / Q000473:pathology; D003216:Conditioning, Operant / Q000502:physiology; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology; D020234:Gait Ataxia / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D007266:Inhibition, Psychological; D007966:Leukodystrophy, Metachromatic / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D008064:Lipidoses / Q000150:complications / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D016555:Matched-Pair Analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology; D010641:Phenotype; D011597:Psychomotor Performance / Q000502:physiology*
D002553:Cerebroside-Sulfatase