Answers are grounded in this paper and cite their sources.
Doubt is thrown on the commonly held view that the pituitary gland contains a general stimulant of plain muscle fibres, since for the isolated intestine there is no evidence of action in such concentration nor of such tissue specificity as would justify that belief. The expenses of this research were defrayed by a grant from the Earl of Moray Fund of the University of Edinburgh.
No takes yet. Share an insight, caveat, or question.
Alex MacDonald (1925) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: