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The Effects of Lead Acetate on the Neural Development of Chick Embryos

Joyce Park, Nicole Porter, Elizabeth Wilson
Franklin & Marshall College, Spring 2001

Lead is a lethal toxin causing behavioral, neurological and cognitive defects. Unfortunately, birds can be exposed to lead via air, water, food, lead shots, batteries, paint, pesticides, and gasoline. Previous researchers have found trends of decreasing net brain weight with increasing amounts of lead in birds. Many deformities have been found in birds caused by lead such as, hydrocephalus, microphthalmia, cranioschisis, decrease of embryo weight, and varying degrees of damage to the central nervous system. In this experiment we observed the effects of neural development on 2-day chick embryos exposed to12.5ug and 25ug of lead acetate. We injected the yolk sac of 2-day chick embryos with a needle with two concentrations of lead acetate (25ug, 12.5ug) or distilled water as a control. We incubated the embryos with lead for two days in 37
[!]C and then examined them under the dissecting microscope for any developmental defects. Upon observation of the lead exposed chick embryos, it was morphologically apparent that the lead, particularly the higher dose, had caused neurological damage. The most common indication of the damage was blood pooling in the hind-brain, upper back and tail region of the chick embryo. Additionally, we observed some abnormally small and underdeveloped embryos. Findings from this experiment imply that the lead interferes with the cell signaling pathways required for neurological development. This experimental discovery can be compared and possibly applied to young children where the brain and nervous system seem to be the targeted regions of damage due to lead exposure.

© Cebra-Thomas, 2001

Last Modified: 31 May 2001

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