Micromolar aluminium may alter neurotransmission | 50863
Journal of Clinical Toxicology

Journal of Clinical Toxicology
Open Access

ISSN: 2161-0495

+44 1478 350008

Micromolar aluminium may alter neurotransmission

International Toxicology Summit & Expo

November 26-28, 2012 Hilton San Antonio Airport, USA

Maria Paula P. Goncalves

Scientific Tracks Abstracts: J Clinic Toxicol

Abstract :

A lthough we have gained important insights on aluminium neurotoxicity little is yet known about the underlying molecular mechanisms. This is particularly the case for aluminium action on neurotransmission, which has a crucial role in the information flow through Nervous System. The overall process, however, has been proved to be quite complex. At a minimum, neurotransmission involves several main aspects, including: neurotransmitters biosynthesis; neurotransmitters storage in synaptic vesicles; local calcium spike in response to stimulation; neurotransmitter release to the extracellular space; neurotransmitter diffusion in the extracellular space; neurotransmitter binding to the target receptor and its activation; and the neurotransmitter desactivation by enzymatic or transport processes. In previous studies we demonstrated that micromolar aluminium relieves calcium downregulation of GABA transporter, when mediating uptake or release of GABA across the presynaptic membrane, due to inhibition of Ca/calmodulin-dependent calcineurin activity. Conversely, inhibition of the (Na + /K + )ATPase by aluminium inhibits the high-affinity (Na + -dependent, hemicholinium-3 sensitive) uptake of choline and the calcium-dependent, K + depolarization evoked release of acetylcholine. Our most recent work shows that micromolar aluminium reduces prolactin secretion downstream of the stimulus-secretion coupling by decreasing the frequency of unitary exocytotic events and by stabilizing the fusion pore diameter to a value smaller than prolactin molecule, thus preventing its discharge into the extracellular space. So, work from several laboratories, including our own, suggests that synapses become dysfunctional when micromolar aluminium is present in the vicinity of the plasma membrane

Biography :

Maria Paula P. Goncalves received her Master of Science in Biology from the Lomonosov Moscow State University and the PhD in Biochemistry from the University of Coimbra in 1992. Latter she became an Integrated Researcher of the Centre for Environmental and Marine Studies. She is Associate Professor in the University of Aveiro. Her main research interest deals with presynaptic mechanisms of neurotransmission, including the aluminium toxicity. She has published more than 30 papers in SCI journals. She is also involved in various projects in the scope of evaluation of cellular response to novel bionanocomposites and development of clean energy systems