Aluminum ingestion alters behaviour and some neurochemicals in rats.

Effect of aluminum (Al) has been investigated on the brain of rats exposed to this metal (500 mg Al/liter in drinking water) daily for 180 days. A significant reduction in the spontaneous locomotor activity was noticed after 90 and 180 days of Al exposure to the rats, the magnitude of the change being almost identical at both the time intervals. Aluminum exposure also produced significant deficits in acquisition and retention of learned response in active avoidance situation, these changes being time dependent. A significant retardation of the extinction of the learned task was noted in Al exposed rats especially at 180 days. There was significant increase in the lipid peroxidation and decrease in the activity of Mg(2+)-ATPase and Na+,K(+)-ATPase in the brain of rats at 180 days after Al exposure. The increase in the contents of the metal was maximum in rest of the brain region (87% of control) followed by hippocampus and cerebral cortex (59% of controls), cerebellum and corpus striatum (43% and 44% of controls, respectively) after 180 days. Whether Al is responsible to initiate neurotoxic effects by producing changes in the structure and function of the plasma membrane needs further investigations.

Effect of chronic cadmium exposure on locomotor behaviour of rats.

Growing male rats were exposed to cadmium (Cd, 100 micrograms/kg, ip) for 51 days and the effect on the different components of locomotor behaviour was assessed on days 38, 46 and 51 of Cd exposure. Significant decrease in distance travelled, stereotypic time and movements, ambulatory time and vertical movements were observed in Cd-exposed rats, whereas the time of rest was increased. The number of entries into the inner as well as the outer squares and the total time spent in the inner squares of the floor area were significantly reduced. Results indicate that Cd exposure results in a general depression in all aspects of motor behaviour leading to decrease in gross locomotor activity. The involvement of an exaggerated emotional reactivity in the behavioural expression of the Cd-treated animals is also emphasized.

Role of aluminium in sporadic motor neuron disease.

In an attempt to ascertain the role of aluminium in sporadic motor neuron disease (MND), trace metals were estimated in blood, plasma and cerebrospinal fluid (CSF) of 38 patients of sporadic MND and 30 controls by direct current plasma emission spectrophotometry. CSF aluminium levels (20.76 +/- 4.38 micrograms/dl) were significantly higher (P less than 0.05) in those patients of MND who presented as progressive bulbar palsy (PBP) as compared to the other subtypes of MND (amyotrophic lateral sclerosis = 7.71 +/- 2.01 micrograms/dl; progressive muscular atrophy = 10.01 +/- 2.41 micrograms/dl) and controls (11.63 +/- 2.82 micrograms/dl). Aluminium may be important in the etiopathogenesis of a subgroup of sporadic MND.