Distribution of PPR of DMX neurons is related to the projection of the neuron. A, identification of and targeted recording from a DMX neuron that projected to the anterior gastric branches of the subdiaphragmic vagus nerve, onto which DiI was placed. Left, epifluorescent image of the DiI fluorescence in the DMX; middle, IR-DIC image of the same observation field with a recording pipette on a DiI-positive neuron; right, fluorescence image of Alexa Fluor 488 injected into the identified neuron via internal solution. B, locations of the DiI-positive recorded DMX neurons (filled squares, DMX neurons classified as type I; open circles, those classified as type II) and the position of the tip of the stimulation electrode (crosses). C, distribution of PPR values among the DMX neurons. Gray bars: distribution of non-identified DMX neurons recorded from rats without DiI pretreatment (the same as in Fig. 1C); open cityscape histogram, that of DiI-positive DMX neurons. Insets above show averaged EPSC traces from two DiI-positive DMX neurons representing type I (left) and type II (right). D, cumulative probability plot based on the histogram in C. The distribution of PPR values of DiI-positive DMX neurons and that of DMX neurons recorded in the slices from non-operated rats were significantly different (Kolmogorov-Smirnov test, p = 0.035).