A, sagittal section of the brainstem showing the position of an electrolytic lesion placed at the effective MLR site (right side) in this experiment. B, a diagram of a sagittal slice (from Paxinos & Watson, 2007) shows the tip of the electrode (grey circle) located in the vicinity of the nucleus cuneiformis (CnF). The electrode was positioned at a 37 deg angle and inserted 1.5 mm lateral to the midline at a depth of 3.0 mm below the surface of the superior colliculus. The fictive locomotion produced by stimulation at this site in this animal is illustrated in Fig. 9. Abbreviations: 7, facial nucleus; Amb, ambiguous nucleus; CnF, nucleus cuneiformis; DpMe, deep mesencephalic nucleus; LPGi, lateral paragigantocellular nicleus; LR4V, lateral recess of the 4th ventricle; Mo5, motor trigeminal nucleus; Me5, mesencephalic trigeminal nucleus; PPTg, pedunculopontine tegmental nucleus; scp, superior cerebellar peduncule; SNR, substantia nigra, reticular part.