Cadmium found to impair cognition and olfaction in mice

Hao Wang, a graduate student with Zhengui Xia in the University of Washington’s Toxicology Program, recently provided the first direct evidence of cadmium’s adverse effects on cognition and olfaction by using an animal model. Cadmium is a common toxic heavy metal pollutant produced by burning fossil fuels, smelting metals and using phosphate fertilizer. Plants readily take up cadmium from the soil and can introduce it to the food chain. When people ingest cadmium, it tends to stay in the body for a long time, having toxic effects on the kidneys, liver, bones, lungs, and testes. Epidemiological studies also correlate cadmium exposure with impaired cognition and olfaction, but Wang’s recently published study is one of the first to establish a direct causal relationship between cadmium exposure and cognitive and olfactory impairment. Wang demonstrated causality by exposing adult male C57BL/6J mice to cadmium in their drinking water for 20 weeks and then comparing their performance in behavioral tests to that of controls. He found impaired hippocampus-dependent learning and memory as well as deficits in short-term olfactory memory and odor-cued olfactory learning and memory. Wang and colleagues published their results in Toxicological Studies.