Abstract
It has been reported that there is an ameliorative effect of cigarette smoking on certain neurological responses and neurodegenerative disorders. The purpose of this study was to examine the neurochemical and neurobehavioral response of cigarette smoke (CS) in the adult male guinea pig brain. Both acute and chronic CS exposure enhanced locomotor behavior and caused a decrease in midbrain dopamine (DA) levels and corresponding increase in 3,4βdihydroxyphenylacetic acid (DOPAC) levels. In addition, CS caused a significant increase in the protein levels of the dopamine D~1~ and D~2~ receptors. CS caused a significant increase in the binding capacity of the D~1~ receptor and a significant decrease in the binding capacity of D~2~. Furthermore, CS caused a significant increase in the binding capacity of the dopamine transporter (DAT). The mechanism by which cigarette smoke exposure increases locomotor activity remains to be elucidated but may include modulation of dopamine neuron activity that emerges after repeated direct smoke exposure. Β© 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:325β335, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20197