Nicotine increases intracellular calcium in rat hippocampal neurons via voltage-gated calcium channels

• Published in: Neuroscience letters 1995-08, Vol.196 (1), p.101-104
• Main Authors: Barrantes, G.E., Murphy, C.T., Westwick, J., Wonnacott, S.
• Format: Article
• Language: English
• Subjects: Aconitine - analogs & derivatives; Aconitine - pharmacology; Alkaloids - pharmacology; Animals; Azocines; Biochemistry and metabolism; Biological and medical sciences; Calcium - metabolism; Calcium Channels - drug effects; Cells, Cultured - drug effects; Central nervous system; Cultured hippocampal neurons; Cytisine; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Fura-2; Hippocampus - drug effects; Membrane Potentials - drug effects; Methyllycaconitine; Nicotine - pharmacology; Nicotinic acetylcholine receptor; Quinolizines; Rats; Rats, Inbred Strains; Time Factors; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/0304-3940(95)11859-U

The effect of nicotinic receptor activation on intracellular calcium concentrations ([Ca 2+] i) was quantitated in populations of cultured hippocampal neurons loaded with Fura-2. Nicotine (50 μM) and cytisine (50μM) increased [Ca 2+] i by 100%. This response was abolished in the presence of the nicotinic antagonist methyllycaconitine (MLA) whereas KCl-evoked increases in [Ca 2+] i were insensitive to MLA. Glial cultures were unaffected by nicotine, although they did respond to glutamate with increased [Ca 2+] i. In hippocampal neurons, responses to nicotinic agonists and KCl were dependent on the presence of extracellular Ca 2+ and were similarly sensitive (85% inhibition) to CdCl 2. These results are consistent with the presence of functional nicotinic receptors on hippocampal neurons. The receptors appear to elevate [Ca 2+] i by promoting the influx of extracellular Ca 2+ through voltage-gated calcium channels.