Fig. 2.

Cortical networks that influence parasympathetic or sympathetic control of the rat stomach. (A) Parasympathetic network: Flattened cortical map of third-order neurons labeled in Layer V of the right hemisphere after transport of RV from the stomach. (B) Sympathetic network: Flattened cortical map of fourth-order neurons labeled in Layer V of the right hemisphere after transport of RV from the stomach of animals in which the vagus nerves were sectioned. In both A and B, the results from 4 animals are overlapped in these maps. The medial wall of the hemisphere is reflected upward and joined to the lateral surface at the midline. The dashed lines indicate the border between agranular (M1) and granular (S1) cortex in the region of the forelimb, trunk, and hindlimb representations. Each small square represents a single labeled neuron. Br, bregma; C, caudal; CC, corpus callosum; INS, insula; M, medial; midline, midline of the hemisphere; mPFC, medial prefrontal cortex; M1, primary motor cortex; M2, secondary motor cortex; RF, rhinal fissure; S1, primary somatosensory cortex. (C) Parasympathetic network: distribution of third-order neurons in various cortical areas after transport of RV from the stomach. (D) Sympathetic network: distribution of fourth-order neurons in various cortical areas after transport of RV from the stomach in animals with sectioned vagus nerves. In both C and D, filled bars, right hemisphere; unfilled bars, left hemisphere.