Parallel increases in [alpha-125I]bungarotoxin binding and alpha 7 nicotinic subunit immunoreactivity during the development of rat hippocampal neurons in culture.
Previous studies have shown that hippocampal neurons cultured at high density express alpha-bungarotoxin binding sites and have alpha 7 nicotinic acetylcholine receptor subunit immunoreactivity [Barrantes, G.E., Rogers, A.T., Lindstrom, J. and Wonnacott, S., Brain Res., 672 (1995) 228-236]. We now examine both of these parameters in well-characterized hippocampal neurons cultured at sufficiently low densities to resolve individual neurons and their processes. The specific binding of [alpha-125I]bungarotoxin is first detectable after 3 days in culture and increases during the next 12 days in culture, reaching a maximum of approximately 30,000 binding sites per cell. This is accompanied, over the same timecourse, by an increase in immunoreactivity for two antibodies that specifically bind to the alpha 7 subunit. Both cell bodies and processes were labelled by 9 days in culture. The timecourse of alpha 7-type nicotinic receptor expression resembles that previously described for synapse formation in hippocampal cultures.
Samuel
N
N
School of Biology and Biochemistry, University of Bath, UK.
Wonnacott
S
S
Lindstrom
J
J
Futerman
A H
AH
D000818:Animals; D001665:Binding Sites; D002038:Bungarotoxins / Q000378:metabolism*; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D007457:Iodine Radioisotopes; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D011978:Receptors, Nicotinic / Q000032:analysis*
D002038:Bungarotoxins; D007457:Iodine Radioisotopes; D011978:Receptors, Nicotinic