Gastric chemoceptive projections to fasciculus solitarius and its dipole field structure.
The gastric branch of the vagus nerve, close to the stomach was stimulated electrically and the evoked potentials recorded from the fasciculus solitarius of frog within the stereotaxic coordinates P 4.1-4.6; L 0.5-0.8 and V 0.3-0.5. A predominantly monophasic negative potential, the amplitude (1.0-3.0 mV) of which rises with increase in stimulus strength up to 6 V, could be recorded. From the velocity of conduction (30 m/sec) it appears that the gastric afferent fibres belong to Group A. The depth-recording resulted in the reversal of the negative sign of the potential at depth beyond 180-200 mu. The significance of the appearance of a positive potential and the cellular configuration of the area of fasciculus is discussed in the context of a possible dipole that might exist in the spatial structure from which the depth-recording has been made.
D000818:Animals; D001001:Anura; D001931:Brain Mapping; D001933:Brain Stem / Q000502:physiology*; D002628:Chemoreceptor Cells / Q000502:physiology*; D005071:Evoked Potentials; D009475:Neurons, Afferent / Q000502:physiology; D009830:Olfactory Bulb / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013270:Stomach / Q000294:innervation*; D014630:Vagus Nerve / Q000502:physiology*