Figure 1.

Temperature effect on stomach muscles

(A) Schematic of the stomatogastric musculature based on the nomenclature from,⁶ including gastric muscles (gm), pyloric muscles (p), and cardio-pyloric (cpv) muscles—adapted from.²⁵ Only the left side of the stomach is shown, with the posterior directed toward the bottom.

(B) Schematic of the experimental setup, showing in vitro dissected muscles with the innervating nerves attached. The LG neuron projects its axon to the lateral ventricular nerve (lvn) and the lateral gastric nerve (lgn). The lgn is stimulated via a suction electrode with a 2-s train at 2 or 5 Hz. The EJPs are recorded via an intracellular electrode in the muscle fiber. .

(C) Effect of temperature on nerve-evoked EJPs and resting membrane voltage (V_rest) (dashed gray line).

(D) Effect of temperature on nerve-evoked EJCs. A gm5b and gm6 muscle fiber are clamped at −80 mV in a two-electrode voltage-clamp configuration. The lgn is stimulated at 5 Hz for 2 s at 11°C and 21°C.

(E) Quantification of the effect of temperature on V_rest for LG muscles (gm5b, gm6, gm8a), PD muscle (cpv1a), LP muscles (cpv4, cpv6), and DG muscle (gm4b). Horizontal and vertical lines represent the median and standard deviation, respectively. Individual points correspond to single muscle fibers. Paired t tests were performed between 11°C and 21°C (gm5b, n = 68, p < 0.0001; gm6, n = 50, p < 0.0001; gm8a, n = 11, p < 0.0001; cpv1a, n = 26, p < 0.0001; cpv4, n = 4, p = 0.0057; cpv6, n = 5, p = 0.0068; gm4b, n = 3, p = 0.0391).