@article{ref1,
title="Differential responsiveness of rat striatal nerve endings to the mitochondrial toxin 3-nitropropionic acid: implications for Huntington's disease",
journal="European journal of neuroscience",
year="2003",
author="Marti, Matteo and Mela, Flora and Ulazzi, Linda and Hanau, Stefania and Stocchi, Sara and Paganini, Francesca and Beani, Lorenzo and Bianchi, Clementina and Morari, Michele",
volume="18",
number="4",
pages="759-767",
abstract="Rat striatal synaptosomes and slices were used to investigate the responsiveness of different populations of nerve terminals to 3-nitropropionic acid (3-NP), a suicide inhibitor of the mitochondrial enzyme succinate dehydrogenase, and to elucidate the ionic mechanisms involved. 3-NP (0.3-3 mm) stimulated spontaneous gamma-aminobutyric acid (GABA), glutamate and [3H]-dopamine efflux but left unchanged acetylcholine efflux from synaptosomes. This effect was associated with a >70% inhibition of succinate dehydrogenase, as measured in the whole synaptosomal population. The facilitation was not dependent on extracellular Ca2+ but relied on voltage-dependent Na+ channel opening, because it was prevented by tetrodotoxin and riluzole. 3-NP also elevated spontaneous glutamate efflux from slices but in a tetrodotoxin-insensitive way. To investigate whether energy depletion could change the responsiveness of nerve endings to a depolarizing stimulus, synaptosomes were pretreated with 3-NP and challenged with pulses of KCl evoking 'quasi-physiological' neurotransmitter release. 3-NP potentiated the K+-evoked GABA, glutamate and [3H]-dopamine release but inhibited the K+-evoked acetylcholine release. The 3-NP induced potentiation of GABA release was Ca2+-dependent and prevented by tetrodotoxin and riluzole whereas the 3-NP-induced inhibition of acetylcholine release was tetrodotoxin- and riluzole-insensitive but reversed by glipizide, an ATP-dependent K+ channel inhibitor. We conclude that the responsiveness of striatal nerve endings to 3-NP relies on activation of different ionic conductances, and suggest that the selective survival of striatal cholinergic interneurons following chronic 3-NP treatment (as in models of Huntington's disease) may rely on the opening of ATP-dependent K+ channels, which counteracts the fall in membrane potential as a result of mitochondrial impairment.<p /><p>Language: en</p>",
language="en",
issn="0953-816X",
doi="10.1046/j.1460-9568.2003.02806.x",
url="http://dx.doi.org/10.1046/j.1460-9568.2003.02806.x"
}