. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONTROL OF NEUROSECRETION 279 weighed individually on a micro-torsion balance. The pupal brain weighed ± mg., and each ganglion, ± mg. c. Assay of cholincrgic substances. Brains or ganglia were dissected from unanesthetized animals and placed in one ml. of sea water containing per cent eserine sulfate (Merck) and brought to pH 4 by the addition of dilute HC1. The excision required about 30 seconds for each brain and 30 to 60 seconds for ganglia. The extracts of 2 or 3 brains, or of 6 to 12 ganglia, w
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONTROL OF NEUROSECRETION 279 weighed individually on a micro-torsion balance. The pupal brain weighed ± mg., and each ganglion, ± mg. c. Assay of cholincrgic substances. Brains or ganglia were dissected from unanesthetized animals and placed in one ml. of sea water containing per cent eserine sulfate (Merck) and brought to pH 4 by the addition of dilute HC1. The excision required about 30 seconds for each brain and 30 to 60 seconds for ganglia. The extracts of 2 or 3 brains, or of 6 to 12 ganglia, were boiled for one minute, cooled, and stored at -- 20° C. (Welsh, 1943). The isolated ventricle of the quahog, Venus mercenaries, was used in the assay of cholinergic substances, according to the method of Welsh (1943). About one-third of the assays were per- formed on ventricles which had been exposed for 15 minutes to 10^6 M LSD-25 (lysergic acid diethyl amide, Sandoz Products Ltd.). As Welsh (1954) has shown, this drug excites the molluscan heart maximally and thereby provides an excellent preparation for the assay of inhibitors of the ventricular beat. LSD treatment also masks the action of any excitors which might be present in the tis- sue extract. d. Choline acetylasc. In these determinations brain homogenates were incu- bated in a solution containing the salts, substrates, and cofactors favoring the acetylation of choline. The incubation media contained eserine to inhibit ChE, which would otherwise hydrolyze the desired product. The presence of fluoride is also necessary to protect the added ATP by inhibiting ATP-ases. For each assay six animals at the same stage of development were anesthetized with carbon dioxide. The brains were excised and ground in a small, conical,. 500 10 msec. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not pe
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
