Neuronal firing patterns of organotypic rat spinal cord cultures in normal and in ACTH/alpha-MSH(4-10) analog (BIM 22015)-supplemented medium.
The spontaneous and evoked electrical patterns of spinal cord explants from 13- to 14-day old rat fetuses grown from 2 to 8 weeks in vitro were compared when fed either with a standard or with an adrenocorticotropic hormone/alpha-melanocyte stimulating hormone (4-10) analog (BIM 22015)-supplemented medium. Standard and BIM 22015-treated cultures developed similar patterns of extracellularly recorded activity which consisted of mostly phasic but also tonic discharges. The standard cultures when treated by BIM 22015 in acute experiments (100 micrograms/ml) showed a decrease in their frequency of discharges which fired in a regular tonic pattern. These effects were neither age- nor dose-dependent but were increased in Ca2+ free medium. The ventral cord neurons chronically fed with BIM 22015 showed a strongly bursting pattern resembling strychnine-induced synchronized bursts. Both these effects, inhibitory (acute) and excitatory (chronic), of the BIM upon spinal cord cultured ventral horn neurons are discussed as possible calcium-dependent phenomena.
Calvet
M C
MC
I.N.S.E.R.M. U336, U.S.T.L., Montpellier, France.
Drian
M J
MJ
Calvet
J
J
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D003470:Culture Media; D004594:Electrophysiology / Q000379:methods; D004622:Embryo, Mammalian; D005071:Evoked Potentials / Q000187:drug effects; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D008838:Microcomputers; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009924:Organ Culture Techniques / Q000379:methods; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D013116:Spinal Cord / Q000502:physiology*
D003470:Culture Media; D010446:Peptide Fragments; C075226:BIM 22015; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; C011394:ACTH (4-10); D002118:Calcium