Get access

Nicotine regulates 5-HT1A receptor gene expression in the cerebral cortex and dorsal hippocampus

Authors

  • Paul J. Kenny,

    1. Psychopharmacology Research Unit, Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, Hodgkin Building, Guy's Campus, London SE1 1UL, UK
    Search for more papers by this author
    • *Present address: Department of Neuropharmacology, CVN-7, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
  • Sandra E. File,

    1. Psychopharmacology Research Unit, Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, Hodgkin Building, Guy's Campus, London SE1 1UL, UK
    Search for more papers by this author
  • Marcus Rattray

    1. Biochemical Neuropharmacology Group, Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, Hodgkin Building, Guy's Campus, London SE1 1UL, UK
    Search for more papers by this author

: Dr M. Rattray, as above.
E-mail: marcus.rattray@kcl.ac.uk

Abstract

The 5-HT1A receptor has previously been shown to be important in mediating the behavioural effects of nicotine. It is possible that nicotine administration might regulate the levels of 5-HT receptors in limbic and cortical regions, and such regulations may underlie adaptive responses to nicotine in the central nervous system. The effects of acute and chronic systemic (–)-nicotine administration on 5-HT1A receptor gene expression were measured by in situ hybridization, in the rat cerebral cortex, dorsal hippocampus and lateral septum. In the cortex, acute nicotine (0.5 mg/kg i.p.) significantly increased the expression of 5-HT1A receptor mRNA 2 h and 24 h after injection. Similarly, acute nicotine significantly increased 5-HT1A receptor mRNA in the dentate gyrus (DG), CA3 and CA1 regions of the dorsal hippocampus 2 h and 24 h after injection. Acute nicotine was without effect in the lateral septum. Chronic nicotine (0.5 mg/kg i.p; twice daily for 7 days) significantly decreased 5-HT1A receptor mRNA in the cortex 2 h after the final injection, but was without effect at 24 h or 72 h. Chronic nicotine caused no changes in 5-HT1A mRNA in the lateral septum or dorsal hippocampus. These data demonstrate that nicotine regulates 5-HT1A receptor gene expression in the cortex and hippocampus. The rapid regulation of expression of 5-HT1A receptor mRNA leads to the hypothesis that nicotine-induced 5-HT release may alter the postsynaptic sensitivity to 5-HT.

Ancillary