Continue from The Developing Brain : Forms of Mercury (Hg) Psychology notes

There are three forms of Mercury: - metallic (silver stuff in thermometer) - Inorganic compounds - Organic compounds (eg. Methyl mercury) (all exists in the environment) Biotransformation Metallic and inorganic mercury | Algae >> organic mercury compounds | fish | humans certain fish concentrate mercury - some fish: swordfish; tuna are high mercury concentrates Hunter - Russell Syndrome ME Hg poisoning in adults: - peripheral sensory loss (start to experience numbness and tingling in limbs and can result in loss of sensation - Ataxia (movements - cerebellum) - Dysarthria - problem forming speech - tunnel vision - people lose peripheral vision Large - Scale Me Hg Poisoning episodes . Minimata Japan (1956 -65) Industrial Plant dumped some form of mercury in the Bay. Fish became contaminated. There was a major fish diet among the people in the area. They therefore had higher mercury. It is different with alcohol which diffuses mother to fetus. It goes back and forth and does not get caught in the tissue. It's in the body for a short time. In the case of heavy metal, once in the body tissue, it does not go away in a few hours. Many cases are overt in adults and children - Children are born with problems. IRAQ (1972) - There was a large shipment of grain seed sent there and it was treated with pesticides. It was milled to make bread and not planted. It effected perhaps 6000 people among them who died. There is a considerable amount of studies. Japan was gradual. Iraq, acute in about a month. Certain females were pregnant therefore infants and fetuses were effected. Minamata Disease became a concern. There is delayed milestones of motor development (mom may not be sick and the fetus may not be apparent abnormal - after a few months there was slow development - similar to cerebral palsy) - abnormal reflexes, muscle tone and movements - difficulties feeding - severe language and cognitive delays It lodges in hair and teeth. Hair has mercury in it. It can be determined how long the person was exposed. Effects of Me Hg on the developing brain 1. Toxic effects - diffuse cell loss throughout neocortex (Adult damage limited. The brain of children exposed after birth is more widespread in fetal brain (killing cells toxic) 2. Teratogenic Effects - - abnormal neuronal migration - abnormalities in cortical layers - cerebellum cortex abnormalities - micr cephally (reduced brain size) to be continued............with Lead (PB) exposure