. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 102 P. J. STEPHENS B s-. S-t FIGURE 6. The different temperature thresholds for peripheral spike generation in excitor axons to the stretcher (s) and bender (b) muscles in an autotomized walking leg of Pachygrapsus crassipes. A. Low intensity stimulus shocks applied to the limb nerve evoked activity in the excitor to the stretcher and an ejp. B. Increasing stimulus intensity recruited the E2 axon to the bender muscle and evoked an ejp. C. At °C two ejp's were recorded from the bender muscle. D. At 30°C, three ejp's were
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 102 P. J. STEPHENS B s-. S-t FIGURE 6. The different temperature thresholds for peripheral spike generation in excitor axons to the stretcher (s) and bender (b) muscles in an autotomized walking leg of Pachygrapsus crassipes. A. Low intensity stimulus shocks applied to the limb nerve evoked activity in the excitor to the stretcher and an ejp. B. Increasing stimulus intensity recruited the E2 axon to the bender muscle and evoked an ejp. C. At °C two ejp's were recorded from the bender muscle. D. At 30°C, three ejp's were recorded from the bender muscle and four ejp's from the stretcher muscle. Calibration 10 mV and 10 ms (from Lazurus el al. 1982). on axons is confined by size constraints, although this technique has been used on unidentified crustacean walking leg axons (Connor, 1975). In such a study, the ionic currents that are involved in the axon spike as well as the depolarizing after-potential could be defined. One area that has received little attention to date involves the effects of temperature on inhibitory nerves. It is known that temperature increases result in inhibitory synapses failing earlier than excitatory (Fig. 4D; Stephens and Atwood, 1981; White, 1983). However, little is known about the effect of temperature on post- versus pre-synaptic inhibition, and the relative temperature-sensitivity of different inhibitors to the same muscle, for example the common inhibitor and specific inhibitors to certain crustacean limb muscles. Studies on the effect of temperature on the firing patterns of neurons has generally been confined to sensory and motor neurons. Is it possible that temperature also influences neurons that secrete hormones, for example those that have a modulatory effect on neuromuscular transmission (HoyletY al., 1974; Jacobs and Atwood, 1981b)? This may have a profound effect on the behavior of the intact animal, more than would be predicted by examination of nerve
Size: 2189px × 1142px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
