Age-related decrease in stimulated glutamate release and vesicular glutamate transporters in APP/PS1 transgenic and wild-type mice.
We assessed baseline and KCl-stimulated glutamate release by using microdialysis in freely moving young adult (7 months) and middle-aged (17 months) transgenic mice carrying mutated human amyloid precursor protein and presenilin genes (APdE9 mice) and their wild-type littermates. In addition, we assessed the age-related development of amyloid pathology and spatial memory impaired in the water maze and changes in glutamate transporters. APdE9 mice showed gradual spatial memory impairment between 6 and 15 months of age. The stimulated glutamate release declined very robustly in 17-month-old APdE9 mice as compared to 7-month-old APdE9 mice. This age-dependent decrease in stimulated glutamate release was also evident in wild-type mice, although it was not as robust as in APdE9 mice. When compared to individual baselines, all aged wild-type mice showed 25% or greater increase in glutamate release upon KCl stimulation, but none of the aged APdE9 mice. There was an age-dependent decline in VGLUT1 levels, but not in the levels of VGLUT2, GLT-1 or synaptophysin. Astrocyte activation as measured by glial acidic fibrillary protein was increased in middle-aged APdE9 mice. Blunted pre-synaptic glutamate response may contribute to memory deficit in middle-aged APdE9 mice.
A.I.Virtanen Institute for Molecular Sciences, University of Kuopio, Finland.
R
R
Minkeviciene
J
J
Ihalainen
T
T
Malm
O
O
Matilainen
V
V
Keksa-Goldsteine
G
G
Goldsteins
H
H
Iivonen
N
N
Leguit
J
J
Glennon
J
J
Koistinaho
P
P
Banerjee
H
H
Tanila
D000375:Aging / Q000378:metabolism* / Q000473:pathology; D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000096:biosynthesis; D016564:Amyloid beta-Protein Precursor / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism / Q000503:physiopathology; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D058225:Plaque, Amyloid / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D053764:Presenilin-1 / Q000235:genetics* / Q000378:metabolism; D009435:Synaptic Transmission / Q000235:genetics; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D005904:Glial Fibrillary Acidic Protein; D053764:Presenilin-1; C493465:Slc17a7 protein, mouse; D050598:Vesicular Glutamate Transport Protein 1; D018698:Glutamic Acid