Abstract
Amyloid peptides (Aβ) can operate as volume transmission (VT) signals since they are continuously released from cells of the central nervous system and diffuse in the extra-cellular space of the brain. They have both regulatory and trophic functions on cellular networks. In agreement with Aβ regulatory actions on glial-neuronal networks, the present paper reports new findings demonstrating that intrastriatal injections of Aβ peptides reduce striatal tyrosine hydroxylase, increase striatal GFAP immunoreactivities and lower pain threshold in experimental rats. Furthermore, it has been demonstrated that exogenous homocysteine (Hcy) binds Aβ(1-40) favouring its β-sheet conformation both in vitro and in vivo and hence the formation of β-fibrils and development of neurotoxicity. Thus, the hypothesis is discussed that Aβ peptides represent crucial VT-signals in the brain and their action is altered by dysmetabolic signals such as high Hcy extra-cellular levels, known to be an important risk factor for Alzheimer's disease.
Original language | English (US) |
---|---|
Pages (from-to) | 21-31 |
Number of pages | 11 |
Journal | Journal of Neural Transmission |
Volume | 114 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2007 |
Externally published | Yes |
Keywords
- β-amyloid peptides
- Alzheimer's disease
- Homocysteine
- Pain threshold
- Volume transmission
ASJC Scopus subject areas
- General Neuroscience