. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONTROL OF NEUROSECRETION 287 first few days at 25° C. and then undergoes a precipitous decrease. This sudden drop in cholinergic substance coincides in time with the reappearance in the brain of detectable ChE. The cholinergic substance then remains at the low and ap- parently constant level until just prior to adult emergence, and then increases five- fold to the high level characteristic of the adult brain. Figure 6 also records corresponding measurements of the cholinergic sub- stance in the ganglia of the same animals w
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CONTROL OF NEUROSECRETION 287 first few days at 25° C. and then undergoes a precipitous decrease. This sudden drop in cholinergic substance coincides in time with the reappearance in the brain of detectable ChE. The cholinergic substance then remains at the low and ap- parently constant level until just prior to adult emergence, and then increases five- fold to the high level characteristic of the adult brain. Figure 6 also records corresponding measurements of the cholinergic sub- stance in the ganglia of the same animals which served as donors of the brains. Here again, the changes are peculiar to the brain and are not encountered in the ganglia. 15 ' Electrical activity reappears ACh do'8 gm.). ..O- O onset of adult development DAYS AT 16 20 24 28 adult 25° C FIGURE 6. The titer of cholinergic substance in the brains and ganglia of pupae chilled for 13 weeks and then brought to 25° C. Ordinate as in Figure 3. •, brain; O, ganglia. 8. The nature of the cholinergic substance Though the nature of the cholinergic substance has not been explored in detail, two observations show that the substance from Cecropia has certain resemblances to ACh. Cecropia brain extracts failed to depress the beat of Venus ventricles which had been previously treated with per cent "Mytolon" [2 : 5-bis(3'diethyl- aminopropylamino)-benzoquinone bis-benzyl chloride, Sterling-Winthrop], a drug which has been shown by Welsh and Taub (1953) to block the action of ACh and related compounds by combining with the specific protein receptor in the Venus ventricle. Furthermore, the compound from Cecropia shares acetylcholine's. 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 perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
