| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4355653 | Hearing Research | 2010 | 12 Pages |
Aging is associated with neurochemical changes in the brain that result in impaired vestibular reflex function. We analysed the concentrations of 9 related neurochemicals (l-arginine, l-citrulline, l-ornithine, agmatine, putrescine, spermidine, spermine, glutamate and γ–aminobutyric acid (GABA)) in the vestibular nucleus of aged (24 months old) and young (4 month old) rats; the cerebellum was analysed for comparison. The effects of the housing conditions of the rats were also investigated. Age significantly affected the concentrations of the 9 neurochemicals in both the vestibular nucleus and cerebellum (P = 0.000). Housing did not have a significant effect and the interaction between age and housing was significant only for the vestibular nucleus (P = 0.03). For both the vestibular nucleus and cerebellum, linear discriminant functions were identified that significantly predicted whether the animals were 4 or 24 months old (P = 0.000). Using multiple regression analysis, only vestibular nucleus spermidine, spermine and l-arginine could be predicted from the other neurochemical variables with an adjusted R2 of >80%. Cluster analyses were performed to determine if the neurochemical variables formed distinct groups and whether this changed as a function of age. For the vestibular nucleus but not the cerebellum, the clusters were substantially different for the 24 month old and 4 month old animals.
Research highlights►Age affected glutamate, GABA and arginine metabolites in the rat vestibular nucleus. ►Linear discriminant functions could reliably predict the animals’ age. ►Vestibular nucleus polyamines and L-arginine could be predicted using regression. Cluster analysis revealed differences for the young and aged vestibular nucleus.
