. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPONENTS OF FEEDING BEHAVIOR IN HYDRA 123 activity of several species of Hydra have failed to show electrical potentials asso- ciated with spontaneous concerted oral flexions. However, Tentacle Contraction Pulses (TCP's) and Column Contraction Pulses (CP's) always associated with tentacle contractions and column contractions respectively, occur spontaneously as single events and in hursts. When H. pirardi feeds on Artcmia, CP bursts and singles are suppressed. TCP bursts are absent although single TCP's occur during this p
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COMPONENTS OF FEEDING BEHAVIOR IN HYDRA 123 activity of several species of Hydra have failed to show electrical potentials asso- ciated with spontaneous concerted oral flexions. However, Tentacle Contraction Pulses (TCP's) and Column Contraction Pulses (CP's) always associated with tentacle contractions and column contractions respectively, occur spontaneously as single events and in hursts. When H. pirardi feeds on Artcmia, CP bursts and singles are suppressed. TCP bursts are absent although single TCP's occur during this period. Rhythmic pulses are evident throughout feeding, as was first observed by Passano and McCullough (1963). After ingestion of the Artemia, CP's return first as single events and then as CP bursts of enhanced frequency. Associated with the return of CP's is a marked increase in TCP firing. §10 o z o o Q V X Li. °.4 z o H ir o <r a. PRE-TEST NO o GSH. 50 ANIMALS WITH TENTACLES REMOVED/£0 AN|MALS W,TH TENTACLES INTACT 10 15 20 25 30 35 MINUTES IN 10- M GSH FIGURE 8. Effect of tentacle removal on light-induced contractions in //. flrardl. Per cent of a group of 50 hydra with tentacles removed (closed circles) and a group of SO intact hydra (open circles) contracting in a 75 second period of bright light followed by a 75 second period of ambient illumination. When a preparation of H. pirardi is exposed to 10 5 M reduced glutathione, effects similar to those resulting from contact with Artcmia salina occur in pace- maker activity. Column Contraction Pulses are inhibited, returning first as singles and then as CP bursts. Tentacle contraction bursts are also inhibited but return as TCP bursts. The Rhythmic Potential Pacemaker System is not, however inhibited by GSH. The frequencies of TCP's and CP's are markedly reduced on administration of GSH, but return at higher than prestimulation values, before returning to control levels. As in the case of exposure to Artcmia, inh
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
