Endocrine, liver-derived IGF-I is of importance for spatial learning and memory in old mice.
J Endocrinol
; 189(3): 617-27, 2006 Jun.
Article
in En
| MEDLINE
| ID: mdl-16731792
ABSTRACT
IGF-I is a neuroprotective hormone, and neurodegenerative disorders, including Alzheimer's disease, have been associated with decreased serum IGF-I concentration. In this study, IGF-I production was inactivated in the liver of adult mice (LI-IGF-I(-/-)), resulting in an approximately 80-85% reduction of circulating IGF-I concentrations. In young (6-month-old) mice there was no difference between the LI-IGF-I(-/-) and the control mice in spatial learning and memory as measured using the Morris water maze test. In old (aged 15 and 18 months) LI-IGF-I(-/-) mice, however, the acquisition of the spatial task was slower than in the controls. Furthermore, impaired spatial working as well as reference memory was observed in the old LI-IGF(-/-) mice. Histochemical analyses revealed an increase in dynorphin and enkephalin immunoreactivities but decreased mRNA levels in the hippocampus of old LI-IGF-I(-/-) mice. These mice also displayed astrocytosis and increased metabotropic glutamate receptor 7a-immunoreactivity. These neurochemical disturbances suggest synaptic dysfunction and early neurodegeneration in old LI-IGF-I(-/-) mice. The decline in serum IGF-I with increasing age may therefore be important for the age-related decline in memory function.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aging
/
Insulin-Like Growth Factor I
/
Maze Learning
/
Liver
/
Memory
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
J Endocrinol
Year:
2006
Document type:
Article
Affiliation country:
Suecia
Publication country:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
/
UK
/
UNITED KINGDOM