Rodent smoke screen

December 8, 2009

Rats passively exposed to tobacco smoke become dependent on nicotine, according to a new study by Dr. Adrie Bruijnzeel and colleagues from the University of Florida in the US. Their findings of how rats' brains respond to exposure to tobacco smoke have implications for the study of the effects of tobacco smoke on the human brain even from passive exposure to other smokers, and for future studies testing new treatments for tobacco addiction. Their work has just been published online in Springer's journal Psychopharmacology.

Nicotine as well as many other compounds in tobacco smoke act together on the brain reward system and are addicting in , but the effects of passive exposure have not been studied. In order to develop drug therapies for tobacco addiction, animal models that investigate the long-term effects of mere passive exposure to the addictive compounds in tobacco smoke are needed.

In a set of four experiments on male Wistar , Dr. Bruijnzeel and colleagues investigated whether rats exposed passively to tobacco smoke would become dependent on nicotine. They specifically looked at how the rats' brains responded to being exposed to tobacco smoke and whether the rats displayed withdrawal symptoms.

For all the experiments, freely moving rats were chronically exposed to tobacco smoke for a few hours per day. In the first experiment, the rats were fitted with an intracranial probe to measure the emotional aspects of tobacco withdrawal. The second experiment looked at whether being exposed to tobacco smoke decreased the rats' self-administration of nicotine. The third experiment investigated whether rats exposed to tobacco smoke were less motivated to eat. Finally, in the fourth experiment, the researchers looked specifically at the effects of tobacco smoke exposure on the brain's hippocampus, or grey matter - the area of the brain most sensitive to smoke and nicotine-induced changes.

The rats exposed to tobacco smoke showed both affective and physical withdrawal signs, as well as nicotine-induced changes in the , which demonstrates that passive exposure to tobacco smoke exposure leads to nicotine dependence.

The authors conclude: "These studies suggest that the rat tobacco smoke exposure model can be used to investigate the effects of tobacco smoke on the human brain and to evaluate the efficacy of novel treatments for tobacco addiction."

More information: Small E et al (2009). exposure induces dependence in rats. Psychopharmacology. DOI 10.1007/s00213-009-1716-z

Source: Springer

Related Stories

Recommended for you

Probing how Americans think about mental life

October 20, 2017
When Stanford researchers asked people to think about the sensations and emotions of inanimate or non-human entities, they got a glimpse into how those people think about mental life.

Itsy bitsy spider: Fear of spiders and snakes is deeply embedded in us

October 19, 2017
Snakes and spiders evoke fear and disgust in many people, even in developed countries where hardly anybody comes into contact with them. Until now, there has been debate about whether this aversion is innate or learnt. Scientists ...

Dutch courage—Alcohol improves foreign language skills

October 18, 2017
A new study published in the Journal of Psychopharmacology, conducted by researchers from the University of Liverpool, Maastricht University and King's College London, shows that bilingual speakers' ability to speak a second ...

Inflamed support cells appear to contribute to some kinds of autism

October 18, 2017
Modeling the interplay between neurons and astrocytes derived from children with Autism Spectrum Disorder (ASD), researchers at University of California San Diego School of Medicine, with colleagues in Brazil, say innate ...

Study suggests psychedelic drugs could reduce criminal behavior

October 18, 2017
Classic psychedelics such as psilocybin (often called magic mushrooms), LSD and mescaline (found in peyote) are associated with a decreased likelihood of antisocial criminal behavior, according to new research from investigators ...

Taking probiotics may reduce postnatal depression

October 18, 2017
Researchers from the University of Auckland and Otago have found evidence that a probiotic given in pregnancy can help prevent or treat symptoms of postnatal depression and anxiety.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.