Continuous depolarization induces choline acetyltransferase activity in septal and hippocampal co-cultured embryonic rat neurons.
We tested the influence of continuous high-K+ treatment on acetylcholine (ACh) release and choline acetyltransferase (ChAT) activity on septal cell culture, and septal and hippocampal cell co-culture obtained from rat embryos. Continuous 9 mM K+ treatment did not affect ACh release and ChAT activity in septal culture, but increased ACh release in co-culture without affecting ChAT activity. A slight increase in extracellular K+ concentration, therefore, induced neuronal excitation. Continuous 55 mM K+ treatment increased ACh release in septal culture. This effect was due to direct excitation of septal neurons. In co-culture, 55 mM K+ treatment increased both ACh release and ChAT activity. These results indicate that hippocampal neurons are indispensable for the depolarization-induced increase in ChAT activity in the early stage of developing septal cholinergic neurons.
Suzuki
Takeshi
T
Department of Basic Biological Sciences, Kyoritsu University of Pharmacy, 1-5-30 Shiba-Koen, Minato-ku, Tokyo 105-8512, Japan. Suzuki-tk@kyoritsu-ph.ac.jp
Shimotohno
Kumiko
K
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000109:Acetylcholine / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D006624:Hippocampus / Q000166:cytology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology*; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D012686:Septal Nuclei / Q000166:cytology*; D014316:Tritium / Q000378:metabolism
D014316:Tritium; D011189:Potassium Chloride; D000105:Acetyl Coenzyme A; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine