Stimulation of the MLR inhibits the discharge of dorsal horn neurons responsive to muscular contraction

We found that electrical stimulation of the mesencephalic locomotor region (MLR) inhibited thp discharge of deep dorsal horn neurons receiving group I II afferent input from the triceps surae muscles. In contrast, contraction of these muscles induced by electrical stimulation of the: tibial nerve act ivated these dorsal hum neurons. Our findings show that descending central motor commands can inhibit dorsal horn interneurons receiving input from gr oup III afferents during exercise. (C) 2000 Elsevier Science B.V. All right s reserved.