The development of responsiveness to substance P and glutamate in the spinal motoneurons of rat fetuses.
The development of responsiveness of motoneurons to substance P (SP) and glutamate was investigated in the isolated spinal cord of the rat fetus at embryonic days 13.5-21.5. The motoneurons at embryonic day 14.5 first responded to SP with a slow depolarization. The responsiveness to SP increased by embryonic days 19.5-21.5. In a low Ca2+ solution, responsiveness was reduced after embryonic day 17.5. Glutamate caused a slow depolarization of motoneurons from embryonic day 13.5. The responsiveness increased until embryonic day 17.5 and decreased thereafter.
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D005071:Evoked Potentials / Q000187:drug effects; D005260:Female; D005865:Gestational Age; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D009046:Motor Neurons / Q000166:cytology / Q000187:drug effects*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects*; D013373:Substance P / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects
D005971:Glutamates; D013373:Substance P; D018698:Glutamic Acid; D002211:Capsaicin