Motor Output from the Brain and Spinal Cord


All skeletal muscles are controlled by activation and inhibition of motor neurons in the spinal cord and brainstem. Motor neurons integrate information from a wide variety of sources in the brain and spinal cord. Simple limb reflexes and basic patterns of limb movements, including locomotion, are coordinated by spinal cord interneurons and sensory neurons. Descending inputs from the reticular formation, the vestibular nuclei and the superior colliculus in the brainstem are important in the control of automatic, axial, postural and locomotor movements. Descending inputs from several areas of the cerebral cortex and from the red nucleus are important in the control of voluntary, distal limb and fine movements. The basal ganglia in the basal forebrain and the cerebellum in the hindbrain are involved in the modification and learning of movements. These structures act indirectly on motor output, via outputs through the thalamus to widespread areas of the cerebral cortex.

Key Concepts

  • All voluntary movements involve motor neurons in the spinal cord and brainstem that cause contraction of skeletal muscles.
  • Neurons in many areas of the brain and spinal cord are active at overlapping times to control voluntary movements.
  • The spinal cord can produce coordinated movements of the limbs, such as locomotion, as well as simple reflexes.
  • The superior colliculus can trigger orienting movements, especially of the eyes and head.
  • Voluntary limb movements involve neurons in several parts of the cerebral cortex, including especially the frontal lobe, which project axons to the spinal cord.
  • Cortical movement control signals are modified by loops to and from the basal ganglia and the cerebellum, going through the thalamus.
  • The basal ganglia modify the speed and amplitude of movements and contribute to learning new movement sequences.
  • The cerebellum adapts movements to altered sensory feedback and may also contribute to a wide variety of other functions, including memory, language and emotion.
  • Patients with movement disorders may in the future be able to control a limb or prosthetic device with ‘their thoughts’, via a brain–machine interface that monitors the activity of some of their cortical neurons.

Keywords: motor neuron; interneuron; spinal cord; locomotion; central pattern generator; motor cortex; cerebellum; basal ganglia; superior colliculus; motor learning

Figure 1. Spinal cord organisation within each spinal segment.
Figure 2. Descending supraspinal pathways into the spinal cord.
Figure 3. The basal ganglia and the cerebellum indirectly modify cerebral cortical motor output (+ indicates an excitatory connection, and − indicates an inhibitory connection).
Figure 4. Prolonged electrical stimulation of a particular location within the frontal lobe of the cerebral cortex causes a monkey's arm to adopt a particular posture (changing hand position is indicated by trails of dots, which converge on the final hand position), regardless of the initial hand position (different trails of dots). (a–f) The results of stimulation of six different locations. Adapted from Graziano et al. ().
Figure 5. A monkey quickly learns to control the rate of action potentials (indicated by the series of black vertical lines in (a) and (b)) of one particular neuron in its motor cortex in a kind of video game (a), in response to an instructed cue (indicated by pink rectangles in (b)). An increase in the smoothed rate of action potentials above a certain threshold value triggers electrical stimulation of an extensor arm muscle, which extends the wrist, and provides the monkey feedback via cursor movement on the computer screen. The monkey correctly increases this neuron's firing rate when instructed to do so and not at other times (c). Moritz et al. (). Reproduced with permission of Springer Nature.


Andalman AS and Fee MS (2009) A basal ganglia‐forebrain circuit in the songbird biases motor output to avoid vocal errors. Proceedings of the National Academy of Sciences of the United States of America 106 (30): 12518–12523.

Barkan CL and Zornik E (2019) Feedback to the future: motor neuron contributions to central pattern generator function. The Journal of Experimental Biology 222 (16): jeb193318.

Basso MA and May PJ (2017) Circuits for action and cognition: a view from the superior colliculus. Annual Review of Vision Science 3: 197–226.

Bastian AJ (2008) Understanding sensorimotor adaptation and learning for rehabilitation. Current Opinion in Neurology 21 (6): 628–633.

Berkowitz A, Roberts A and Soffe SR (2010) Roles for multifunctional and specialized spinal interneurons during motor pattern generation in tadpoles, zebrafish larvae, and turtles. Frontiers in Behavioral Neuroscience 4: 36. DOI: 10.3389/fnbeh.2010.00036.

Bostan AC, Dum RP and Strick PL (2013) Cerebellar networks with the cerebral cortex and basal ganglia. Trends in Cognitive Sciences 17 (5): 241–254.

Briggman KL and Kristan WB (2008) Multifunctional pattern‐generating circuits. Annual Review of Neuroscience 31: 271–294.

Broussard DM, Titley HK, Antflick J and Hampson DR (2011) Motor learning in the vor: the cerebellar component. Experimental Brain Research 210 (3–4): 451–463.

Brown TG (1911) The intrinsic factors in the act of progression in the mammal. Proceedings of the Royal Society of London 84: 308–319.

Calabresi P, Picconi B, Tozzi A, Ghiglieri V and Di Filippo M (2014) Direct and indirect pathways of basal ganglia: a critical reappraisal. Nature Neuroscience 17 (8): 1022–1030.

Cote MP, Murray LM and Knikou M (2018) Spinal control of locomotion: individual neurons, their circuits and functions. Frontiers in Physiology 9: 784.

Del Negro CA, Funk GD and Feldman JL (2018) Breathing matters. Nature Reviews. Neuroscience 19 (6): 351–367.

Diedrichsen J, King M, Hernandez‐Castillo C, Sereno M and Ivry RB (2019) Universal transform or multiple functionality? Understanding the contribution of the human cerebellum across task domains. Neuron 102 (5): 918–928.

Doyon J, Bellec P, Amsel R, et al. (2009) Contributions of the basal ganglia and functionally related brain structures to motor learning. Behavioural Brain Research 199 (1): 61–75.

Ferreira‐Pinto MJ, Ruder L, Capelli P and Arber S (2018) Connecting circuits for supraspinal control of locomotion. Neuron 100 (2): 361–374.

Glickstein M (2007) What does the cerebellum really do? Current Biology 17 (19): R824–R827.

Graybiel AM (2008) Habits, rituals, and the evaluative brain. Annual Review of Neuroscience 31: 359–387.

Graziano MS (2016) Ethological action maps: a paradigm shift for the motor cortex. Trends in Cognitive Sciences 20 (2): 121–132.

Graziano MS, Taylor CS and Moore T (2002) Complex movements evoked by microstimulation of precentral cortex. Neuron 34 (5): 841–851.

Green AM and Angelaki DE (2010) Internal models and neural computation in the vestibular system. Experimental Brain Research 200 (3–4): 197–222.

Grillner S and El Manira A (2020) Current principles of motor control. Physiological Reviews 100: 271–320.

Helmholtz HL (1910) Handbuch der physiologischen optik (Treatise on Physiological Optics). Verlag von Leopold Voss: Hamburg.

von Holst E and Mittlestaedt H (1950) Das reafferenzprincip (the reafference principle). Naturwissenschaften 37: 464–476.

Hoppenbrouwers SS, Schutter DJ, Fitzgerald PB, Chen R and Daskalakis ZJ (2008) The role of the cerebellum in the pathophysiology and treatment of neuropsychiatric disorders: a review. Brain Research Reviews 59 (1): 185–200.

Keifer J and Houk JC (1994) Motor function of the cerebellorubrospinal system. Physiological Reviews 74 (3): 509–542.

Kiehn O (2016) Decoding the organization of spinal circuits that control locomotion. Nature Reviews. Neuroscience 17 (4): 224–238.

Kim LH, Sharma S, Sharples SA, et al. (2017) Integration of descending command systems for the generation of context‐specific locomotor behaviors. Frontiers in Neuroscience 11: 581.

Klarner T and Zehr EP (2018) Sherlock holmes and the curious case of the human locomotor central pattern generator. Journal of Neurophysiology 120 (1): 53–77.

Lee C, Rohrer WH and Sparks DL (1988) Population coding of saccadic eye movements by neurons in the superior colliculus. Nature 332: 357–360.

Lemon RN (2008) Descending pathways in motor control. Annual Review of Neuroscience 31: 195–218.

Li WC, Roberts A and Soffe SR (2010) Specific brainstem neurons switch each other into pacemaker mode to drive movement by activating NMDA receptors. Journal of Neuroscience 30 (49): 16609–16620.

Minassian K, Hofstoetter US, Dzeladini F, Guertin PA and Ijspeert A (2017) The human central pattern generator for locomotion: does it exist and contribute to walking? The Neuroscientist 23 (6): 649–663.

Molinari M, Chiricozzi FR, Clausi S, et al. (2008) Cerebellum and detection of sequences, from perception to cognition. Cerebellum 7 (4): 611–615.

Moritz CT, Perlmutter SI and Fetz EE (2008) Direct control of paralysed muscles by cortical neurons. Nature 456 (7222): 639–642.

Morton SM and Bastian AJ (2004) Cerebellar control of balance and locomotion. The Neuroscientist 10 (3): 247–259.

Moult PR, Cottrell GA and Li WC (2013) Fast silencing reveals a lost role for reciprocal inhibition in locomotion. Neuron 77 (1): 129–140.

Moulton EA, Schmahmann JD, Becerra L and Borsook D (2010) The cerebellum and pain: passive integrator or active participator? Brain Research Reviews 65 (1): 14–27.

Nelson AB and Kreitzer AC (2014) Reassessing models of basal ganglia function and dysfunction. Annual Review of Neuroscience 37: 117–135.

Omrani M, Kaufman MT, Hatsopoulos NG and Cheney PD (2017) Perspectives on classical controversies about the motor cortex. Journal of Neurophysiology 118 (3): 1828–1848.

Papale AE and Hooks BM (2018) Circuit changes in motor cortex during motor skill learning. Neuroscience 368: 283–297.

Peters AJ, Liu H and Komiyama T (2017) Learning in the rodent motor cortex. Annual Review of Neuroscience 40: 77–97.

Prut Y and Fetz EE (1999) Primate spinal interneurons show pre‐movement instructed delay activity. Nature 401 (6753): 590–594.

Sacchetti B, Scelfo B and Strata P (2009) Cerebellum and emotional behavior. Neuroscience 162 (3): 756–762.

Slutzky MW (2019) Brain‐machine interfaces: powerful tools for clinical treatment and neuroscientific investigations. The Neuroscientist 25 (2): 139–154.

Soffe SR (1989) Roles of glycinergic inhibition and n‐methyl‐d‐aspartate receptor mediated excitation in the locomotor rhythmicity of one half of the xenopus embryo central nervous system. The European Journal of Neuroscience 1: 561–571.

Sperry RW (1950) Neural basis of the spontaneous optokinetic response produced by visual inversion. Journal of Comparative and Physiological Psychology 43 (6): 482–489.

Stoodley CJ and Schmahmann JD (2010) Evidence for topographic organization in the cerebellum of motor control versus cognitive and affective processing. Cortex 46 (7): 831–844.

Talpalar AE, Endo T, Low P, et al. (2011) Identification of minimal neuronal networks involved in flexor‐extensor alternation in the mammalian spinal cord. Neuron 71 (6): 1071–1084.

Turner RS and Desmurget M (2010) Basal ganglia contributions to motor control: a vigorous tutor. Current Opinion in Neurobiology 20 (6): 704–716.

Wichmann T, DeLong MR, Guridi J and Obeso JA (2011) Milestones in research on the pathophysiology of Parkinson's disease. Movement Disorder 26 (6): 1032–1041.

Ziskind‐Conhaim L and Hochman S (2017) Diversity of molecularly defined spinal interneurons engaged in mammalian locomotor pattern generation. Journal of Neurophysiology 118 (6): 2956–2974.

Further Reading

Kandel ER, Schwartz JH, Jessell TM, Siegelbaum SA and Hudspeth AJ (2013) Principles of Neural Science, 5th edn. McGraw‐Hill: New York.

Luo L (2017) Principles of Neurobiology. Taylor & Francis Group: New York.

Nicolelis MA (2011) Beyond Boundaries. Times Books: New York.

Nicholls JG, Martin AR, Fuchs PA, et al. (2011) From Neuron to Brain, 5th edn. Sinauer Associates: Sunderland.

Purves D, Augustine GJ, Fitzpatrick D, et al. (2018) Neuroscience, 6th edn. Oxford University Press: New York.

Squire L, Berg D, Bloom FE, et al. (2013) Fundamental Neuroscience, 4th edn. Academic Press: Waltham.

Ziskind‐Conhaim L, Fetcho JR, Hochman S, MacDermott AB and Stein PSG (2010) Neurons and Networks in the Spinal Cord. Blackwell Publishing: Boston On behalf of the New York Academy of Sciences.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Berkowitz, Ari(May 2020) Motor Output from the Brain and Spinal Cord. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000189.pub4]