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Updated: Aug 29, 2026

Preparation of Synaptoneurosomes from Mouse Cortex using a Discontinuous Percoll-Sucrose Density Gradient
Published on: September 17, 2011
Selective prion protein binding to synaptic components is modulated by oxidative and nitrosative changes induced by
Y Morot-Gaudry-Talarmain1, H Rezaei, L Guermonprez
1Laboratoire de Neurobiologie Cellulaire et Moléculaire, CNRS, Gif-sur-Yvette, France. morot@nbcm.cnrs-gif.fr
Abstract:
Choline acetyltransferase (ChAT) and choline transport are decreased after nitrosative stress. ChAT activity is altered in scrapie-infected neurons, where oxidative stress develops. Cellular prion protein (PrPc) may play a neuroprotective function in participating in the redox control of neuronal environment and regulation of copper metabolism, a role impaired when PrPc is transformed into PrPSc in prion pathologies. The complex cross-talk between PrPc and cholinergic neurons was analyzed in vitro using peroxynitrite and Cu2+ treatments on nerve endings isolated from Torpedo marmorata, a model of the motoneuron pre-synaptic element. Specific interactions between solubilized synaptic components and recombinant ovine prion protein (PrPrec) could be demonstrated by Biacore technology. Peroxynitrite abolished this interaction in a concentration-dependent way and induced significant alterations of neuronal targets. Interaction was restored by prior addition of peroxynitrite trapping agents. Cu2+ (in the form of CuSO4) treatment of synaptosomes triggered a milder oxidative effect leading to a bell-shaped increase of PrPrec binding to synaptosomal components, counteracted by the natural thiol agents, glutathione and thioredoxin. Copper(II)-induced modifications of thiols in several neuronal proteins. A positive correlation was observed between PrPrec binding and immunoreactive changes for calcineurin B and its partners, suggesting a synergy between calcineurin complex and PrP for copper regulation.
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