Impact of Lead on the Nervous System

Lead as a Toxicant to an Organ or Organ System

Lead is basically a naturally occurring toxic metal whose increased use in the recent past has contributed to widespread environmental contamination and human exposure. The naturally occurring toxic metal contributes to huge public health problems across the globe because of increased human exposure. The effects or toxicity of lead on an organ or organ system has contributed to extensive research as part of measures to develop ways of preventing these effects and minimizing human exposure to lead. One of the researches that have been carried out in the past decade includes a study by a group of researchers on the cellular impact of lead poisoning and its medical picture. Brochin et. al. (2008) carried out the study to examine the effects of lead intoxication on the nervous system, where the toxic metal has considerable detrimental effects as compared to other organ system.

According to the findings of their study, Brochin et. al (2008) states that the toxic metal blocks the N-methyl-D-aspartate receptor in the nervous system. This receptor is an effective receptor that plays a crucial role in the maturation of brain plasticity i.e. The changes that take place in brain organization. As a result of the blockage of N-methyl-D-aspartate receptor in the brain, there is an interruption of long-term potentiation that in turn restricts the permanent intake and storage of newly acquired knowledge. Moreover, the toxicity contributes to elevated blood levels which hinder the normal functioning of blood-brain barrier.

The blood-brain barrier usually has a significant role or function in sustaining the nervous system's fluid environment. It consists of several endothelial cells that are connected by tight junctions and become surrounded by astrocytes that are more than neurons in brain. According to the findings of studies, lead toxicity plays a vital role in communication between these endothelial cells and astrocytes. Lead toxicant is one of the most dangerous toxicants to the blood-barrier function in terms of maintaining the nervous system's fluid environment. Unlike the other organs in the body that transfer molecules through simple means of diffusion, the blood-brain barrier selects only specific and important water-soluble molecules to transport them through the use of carriers in the plasma membrane. In case of lead toxicity, the brain-barrier is vulnerable to trauma, which may in turn impair the transportation process.

Patel (2000) concurs with this group of researchers through examining the general way with lead toxicity affects the nervous system. As evident in the effect of lead toxicity on the brain-barrier function of the nervous system, the dysfunctions generated by this toxic metal on this organ system are attributed to its ability to restrain or imitate calcium actions. Actually, lead affects the brain-barrier function by inhibit the transportation of the essential molecules.

Despite the differences in the process through which lead enter the bloodstream, it is always distributed in three major components i.e. soft tissue, blood, and mineralized tissue. As evident in its effect on the nervous system, the toxic metal interferes with the normal cell function and physiological procedures. The ability of lead to interfere with the blood-barrier function is associated with the central role calcium ions, especially with regards to helping convert the electrical pulse into a chemical signal.