Effects of opiates on the growth of neuron-enriched cultures from chick embryonic brain.
Neuron-enriched cultures derived from 6-day-old chick embryo cerebral hemispheres were treated with morphine or methadone, 10(-5) M or 10(-6) M, on days 4-6 or 6-8 in culture and were evaluated morphologically and biochemically at day 9 using phase contrast microscopy and choline acetyltransferase activity (ChAT) as a cholinergic marker. The treatment of the cultures with morphine markedly affected their growth pattern; specifically, we observed an increased number of flat cells presumptively glia, and aggregates sided by flat cells and devoid of thick bundles of neuritic processes that normally characterize neuron-enriched cultures. These morphologic changes were reflected in a drastic decrease of ChAT activity in cultures treated from day 4 to day 6 but not from 6 to 8. In contrast to morphine, exposure to 10(-6) M methadone from day 4 to day 6 resulted in reduced ChAT activity but the growth pattern of the cultures remained morphologically intact. We suggest that morphine exerts a general neurotoxic effect whereas methadone may affect some specific cholinergic function.
Sakellaridis
N
N
Department of Pharmacology, University of Colorado School of Medicine, Denver 80262.
Mangoura
D
D
Vernadakis
A
A
D000818:Animals; D001921:Brain / Q000166:cytology* / Q000187:drug effects / Q000196:embryology; D002478:Cells, Cultured; D002642:Chick Embryo; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D003712:Dendrites / Q000187:drug effects / Q000502:physiology; D008691:Methadone / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*
D009294:Narcotics; D009020:Morphine; D002795:Choline O-Acetyltransferase; D008691:Methadone