Hibernation model of tau phosphorylation in hamsters: selective vulnerability of cholinergic basal forebrain neurons - implications for Alzheimer's disease.
Neurofibrillar tangles made up of 'paired helical filaments' (PHFs) consisting of hyperphosphorylated microtubule-associated protein tau are major hallmarks of Alzheimer's disease (AD). Tangle formation selectively affects certain neuronal types and systematically progresses throughout numerous brain areas, which reflects a hierarchy of neuronal vulnerability and provides the basis for the neuropathological staging of disease severity. Mechanisms underlying this selective neuronal vulnerability are unknown. We showed previously that reversible PHF-like phosphorylation of tau occurs during obligate hibernation. Here we extend these findings to facultative hibernators such as Syrian hamsters (Mesocricetus auratus) forced into hibernation. In this model, we showed in the basal forebrain projection system that cholinergic neurons are selectively affected by PHF-like phosphorylated tau, while gamma-aminobutyric acid (GABA)ergic neurons are largely spared, which shows strong parallels to the situation in AD. Formation of PHF-tau in these neurons apparently does not affect their function as pacemaker for terminating hibernation. We conclude that although formation of PHF-like phosphorylated tau in the mammalian brain follows a certain hierarchy, affecting some neurons more frequently than others, it is not necessarily associated with impaired neuronal function and viability. This indicates a more general link between PHF-like phosphorylation of tau and the adaptation of neurons under conditions of a 'vita minima'.
Härtig
Wolfgang
W
Department of Neurochemistry, Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany. hartig@medizin.uni-leipzig.de
Stieler
Jens
J
Boerema
Ate S
AS
Wolf
Jennifer
J
Schmidt
Udo
U
Weissfuss
Jana
J
Bullmann
Torsten
T
Strijkstra
Arjen M
AM
Arendt
Thomas
T
D000109:Acetylcholine / Q000378:metabolism*; D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D006224:Cricetinae; D003599:Cytoskeleton / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000502:physiology; D006605:Hibernation / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D009474:Neurons / Q000502:physiology*; D010766:Phosphorylation; D016548:Prosencephalon / Q000166:cytology*; D050494:Vesicular Acetylcholine Transport Proteins / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism; D016875:tau Proteins / Q000378:metabolism*
D002135:Calcium-Binding Proteins; D050494:Vesicular Acetylcholine Transport Proteins; D016875:tau Proteins; D005680:gamma-Aminobutyric Acid; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine