Ge. Barrantes et al., NICOTINE INCREASES INTRACELLULAR CALCIUM IN RAT HIPPOCAMPAL-NEURONS VIA VOLTAGE-GATED CALCIUM CHANNELS, Neuroscience letters, 196(1-2), 1995, pp. 101-104
The effect of nicotinic receptor activation on intracellular calcium c
oncentrations ([Ca2+](i)) was quantitated in populations of cultured h
ippocampal neurons loaded with Fura-2. Nicotine (50 mu M) and cytisine
(50 mu M) increased [Ca2+](i) by 100%. This response was abolished in
the presence of the nicotinic antagonist methyllycaconitine (MLA) whe
reas KCl-evoked increases in [Ca2+](i) were insensitive to MLA. Glial
cultures were unaffected by nicotine, although they did respond to glu
tamate with increased [Ca2+](i). In hippocampal neurons, responses to
nicotinic agonists and KCl were dependent on the presence of extracell
ular Ca2+ and were similarly sensitive (85% inhibition) to CdCl2. Thes
e results are consistent with the presence of functional nicotinic rec
eptors on hippocampal neurons. The receptors appear to elevate [Ca2+](
i) by promoting the influx of extracellular Ca2+ through voltage-gated
calcium channels.