Figure 1.

Schematic illustration of the reticulospinal system. (A) Higher central nervous system centres of motion control send their signals to the mesencephalic locomotor region (MLR). The MLR is bilaterally linked to its downstream target, the gigantocellular reticular nucleus (NRG), which gives rise to the reticulospinal tract and drives the central pattern generators (CPG) for motoneuron activation and locomotion. (B and C) Horizontal section of the human (B) and cross section of the rat (C) midbrain at the level of the superior colliculi depicting the MLR (B: landmarks based on Afshar et al⁹⁰; C: landmarks based on Paxinos and Watson⁹¹). CNF, cuneiform nucleus; PPN, pedunculopontine nucleus.