Effect of Chronic Sublethal Cyanide Admin- istration on Brain Neurotransmitters and Behaviour in Rats

With increasing industrialisation man is continuously disturbing the delicate ecological balance. Among the different sources which cause environmental deterioration, hydrogen cyanide is the most important one. Acute cyanide poisoning in man and animals results in incoordination of movements, convulsions, coma and respiratory arrest. At the molecular level it is well known that cyanide inhibits cytochrome c oxidase. This results in histotoxic hypoxia. It could be anticipated that these profound metabolic changes will affect a large number of enzyme systems and also those involved in the synthesis and metabolism of neurotransmitters in the CNS. But due to effective detoxification of cyanide, cumulative effects of cyanide are rarely seen, but even sublethal doses may at times alter the physiological parameters when administered over a period of time. There are few studies on the effect of chronic sublethal cyanide intoxication on motor performance , motor impairments in these animals are manifested as muscular incoordination or increased whole body locomotion, but they were not quantified. Chronic cyanide toxicity resulting from nutritional sources leads to blindness and tropical neuropathy. As the literature on the chronic e ffec t s o f cyan ide on behav iour and b ra in neurotransmitters are scanty, this study aims to evaluate the effects of chronic sublethal sodium cyanide intoxication on motor coordination and neurotransmitter levels in discrete regions of the brain in albino rats.