Chronic exposure to aluminium decreases NADPH-diaphorase positive neurons in the rat cerebral cortex

Aluminium (Al) exposure is neurotoxic and is considered a possible etiologi cal factor for many neurodegenerative disorders. Since it is known that Al impairs the glutamate-nitric oxide-cGMP pathway in neurons, this study was carried out to monitor the expression of NADPH-d in some central nervous sy stem areas of rats after chronic administration of Al in drinking water. We tested three different nervous areas known to contain NADPH-diaphorase pos itive neurons: two cortical area (somatosensory cerebral cortex and cerebra l cortex), a deep brain area (dorsolateral periaqueductal gray matter) and a spinal area (lumbar enlargement of the spinal cord). Our data showed that Al significantly decreased NADPH-d positive neurons in the cerebral cortex and the: NADPH-d staining of many granular neurons in the cerebellum. We a lso found that Al did not cause neuron loss or apoptosis in the cerebral co rtex. These findings suggest that the cortical nitroxidergic neurons and gr anule cells were a specific target of Al neurotoxicity. (C) 2001 Elsevier S cience B.V. All rights reserved.