Journal of Neural Transmission

, Volume 114, Issue 1, pp 21–31

Aβ peptides as one of the crucial volume transmission signals in the trophic units and their interactions with homocysteine. Physiological implications and relevance for Alzheimer’s disease

Authors

  • L. F. Agnati
    • Department of Biomedical Sciences, Section of PhysiologyUniversity of Modena and Reggio Emilia
    • IRCCS San Camillo
  • S. Genedani
    • Department of Biomedical Sciences, Section of PharmacologyUniversity of Modena and Reggio Emilia
  • G. Leo
    • Department of Biomedical Sciences, Section of PhysiologyUniversity of Modena and Reggio Emilia
  • A. Forni
    • Department of ChemistryUniversity of Modena and Reggio Emilia
  • A. S. Woods
    • Department of Health and Human ServicesNational Institute on Drug Abuse
  • M. Filaferro
    • Department of Biomedical Sciences, Section of PharmacologyUniversity of Modena and Reggio Emilia
  • R. Franco
    • Department of Biochemistry and Molecular BiologyUniversity of Barcelona
  • K. Fuxe
    • Department of NeurosciencesKarolinska Institutet
Article

DOI: 10.1007/s00702-006-0564-9

Cite this article as:
Agnati, L., Genedani, S., Leo, G. et al. J Neural Transm (2007) 114: 21. doi:10.1007/s00702-006-0564-9

Summary.

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.

Keywords: β-amyloid peptides, homocysteine, volume transmission, pain threshold, Alzheimer’s disease
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Copyright information

© Springer-Verlag 2006