NEUROTOXICANTS: A THREAT TO YOUNG BRAINS
The number of children suffering from learning and behavioural disorders seems to be on the increase and incidence of neurological disease in later life is also rising. Scientists are concerned that exposure of very young or unborn children to chemicals in the environment that damage the nervous system - neurotoxicants - could be responsible for these disorders. Therefore, research into the effects of neurotoxicants is a priority in the Sixth Framework Programme. Mercury and PCBs (polychlorinated biphenyls) are examples that accumulate in both the environment and the food chain. Their impact on people, particularly children, is poorly understood and the result of long-term, low-dose exposure to a combination of such chemicals remains a mystery. A Specific Targeted Research Project, known as DEVNERTOX, is investigating the effects of neurotoxicants on the developing nervous system, and aims to devise standard procedures for assessing neurotoxicity with reduced involvement of live animals.
PCBs comprise a group of chemicals that have been used in a variety of industrial products, including hydraulic fluids. Mercury from industry and natural sources is converted into organic methyl mercury by bacteria in rivers and seas. It has been suggested that both types of compound can cause memory and language deficits at levels commonly experienced by the general population. In addition, PCBs are hormone disrupters.
DEVNERTOX involves ten groups with expertise in a range of disciplines from cell biology to behavioural neuroscience. Neurotoxicants are a challenge for researchers because the nervous system is so complex. Observable changes in behaviour are far removed from the biochemical responses of cells to toxicants. The project will simultaneously study behavioural effects on live animals, and physiological effects on cultured cells. But how do the cellular changes translate into behaviour? By establishing which types of nervous cell display such effects, and understanding the mechanisms involved, scientists hope to devise a cellbased method for studying neurotoxicity in general.
If the project is successful, future work on neurotoxicants may become less reliant on live animals. Apart from the ethical problems of animal experiments, animals such as rats reflect only in part the complexity of human brain function. Studies on laboratory animals are thought to underestimate the human toxicity of these chemicals by up to four times.
Project group members are breaking new ground by studying the effects of methyl mercury and PCBs in combination. A few studies have suggested that the combined toxicity of these pollutants may be worse than the sum of their individual effects, yet they are often ingested together.
Children - and unborn babies in particular - may be most at risk from neurotoxicants as their nervous systems are still developing. In fact, foetuses show responses at levels too low to affect adult nerve cells. And the consequences could last throughout adulthood, causing hypersensitivity to other chemicals, or neural disease in old age. The DEVNERTOX studies will focus on exposing young and developing nervous cells. Animal studies will follow individuals through to old age, to test the long-term effects of early exposure.
The project will publish its results in scientific journals and at conferences, and will make information available to the public via a dedicated website. The group hopes the work will eventually allow new chemicals to be screened for potential neurotoxic effects.
List of Partners
- Karolinska Institutet (Sweden)
- University of Pavia (Italy)
- University of Parma (Italy)
- Fundacion Valenciana de Investigaciones Biomedicas (Spain)
- Catholic University of Leuven (Belgium)
- Uppsala University (Sweden)
- Nofer Institute (Poland)
- University of Bari (Italy)
- Dublin Trinity College (Ireland)
- Full title:
- Toxic threats to the developing nervous system: in vivo and in vitro studies on the effects of mixture of neurotoxic substances potentially contaminating food
- Contract n°:
- Project co-ordinator:
- Sandra Ceccatelli, Karolinska Institutet, Sandra.Ceccatelli@imm.ki.se
- EC Scientific Officer:
- Valérie Rolland, firstname.lastname@example.org
- EU contribution:
- € 2.4M
- Specific Targeted Research Project