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 movement involves 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 the final hand position), regardless of the initial hand position (different trails of dots). (a)–(f) Show the results of stimulation of six different locations. Adapted from Graziano et al., with permission from Elsevier.

Figure 5.

A monkey quickly learns to control the rate of action potentials (indicated by the series of black vertical lines in (a)–(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). Reprinted from Moritz et al., with permission from Nature Publishing Group.



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 USA 106(30): 12518–12523.

Baillieux H, De Smet HJ, Paquier PF, De Deyn PP and Marien P (2008) Cerebellar neurocognition: Insights into the bottom of the brain. Clinical Neurology and Neurosurgery 110(8): 763–773.

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.

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.

Calancie B, Needham‐Shropshire B, Jacobs P et al. (1994) Involuntary stepping after chronic spinal cord injury. Evidence for a central rhythm generator for locomotion in man. Brain 117(part 5): 1143–1159.

DeLong MR and Wichmann T (2007) Circuits and circuit disorders of the basal ganglia. Archives of Neurology 64(1): 20–24.

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.

Gandhi NJ and Katnani HA (2011) Motor functions of the superior colliculus. Annual Review of Neuroscience 34: 205–231.

Garcia AJ 3rd, Zanella S, Koch H, Doi A and Ramirez JM (2011) Chapter 3 – networks within networks: the neuronal control of breathing. Progress in Brain Research 188: 31–50.

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

Goulding M (2009) Circuits controlling vertebrate locomotion: moving in a new direction. Nature Reviews Neuroscience 10(7): 507–518.

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

Graziano M (2006) The organization of behavioral repertoire in motor cortex. Annual Review of Neuroscience 29: 105–134.

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.

Green AM and Kalaska JF (2011) Learning to move machines with the mind. Trends in Neuroscience 34(2): 61–75.

Grillner S and Jessell TM (2009) Measured motion: searching for simplicity in spinal locomotor networks. Current Opinion in Neurobiology 19(6): 572–586.

Grossmann KS, Giraudin A, Britz O, Zhang J and Goulding M (2010) Genetic dissection of rhythmic motor networks in mice. Progress in Brain Research 187: 19–37.

Guertin PA (2009) The mammalian central pattern generator for locomotion. Brain Research Reviews 62(1): 45–56.

Harkema SJ (2008) Plasticity of interneuronal networks of the functionally isolated human spinal cord. Brain Research Reviews 57(1): 255–264.

Hatsopoulos NG and Donoghue JP (2009) The science of neural interface systems. Annual Review of Neuroscience 32: 249–266.

Hatsopoulos NG and Suminski AJ (2011) Sensing with the motor cortex. Neuron 72(3): 477–487.

Helmholtz HL (1910) Handbuch der physiologischen optik (treatise on physiological optics). Hamburg: Verlag von Leopold Voss.

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.

Jankowska E (1992) Interneuronal relay in spinal pathways from proprioceptors. Progress in Neurobiology 38: 335–378.

Jordan LM, Liu J, Hedlund PB, Akay T and Pearson KG (2008) Descending command systems for the initiation of locomotion in mammals. Brain Research Reviews 57(1): 183–191.

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

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.

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. Neuroscientist 10(3): 247–259.

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.

Nicolelis MA and Lebedev MA (2009) Principles of neural ensemble physiology underlying the operation of brain–machine interfaces. Nature Reviews Neuroscience 10(7): 530–540.

Nudo RJ, Milliken GW, Jenkins WM and Merzenich MM (1996) Use‐dependent alterations of movement representations in primary motor cortex of adult squirrel monkeys. Journal of Neuroscience 16(2): 785–807.

O'Doherty JE, Lebedev MA, Ifft PJ et al. (2011) Active tactile exploration using a brain–machine–brain interface. Nature 479(7372): 228–231.

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.

Sanes JN and Donoghue JP (2000) Plasticity and primary motor cortex. Annual Review of Neuroscience 23: 393–415.

Schwartz AB (2007) Useful signals from motor cortex. Journal of Physiology 579(Pt 3): 581–601.

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.

Strick PL, Dum RP and Fiez JA (2009) Cerebellum and nonmotor function. Annual Review of Neuroscience 32: 413–434.

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.

Further Reading

Kandel ER, Schwartz JH and Jessell TM (2000) Principles of Neural Science, 4th edn. New York: McGraw‐Hill.

Kiehn O, Harris‐Warrick RM, Jordan LM, Hultborn H and Kudo N (1998) Neuronal Mechanisms for Generating Locomotor Activity. New York: The New York Academy of Sciences.

Nichols JG, Martin AR, Wallace BG and Fuchs PA (2001) From Neuron to Brain, 4th edn. Sunderland, MA: Sinauer Associates.

Purves D, Augustine GJ, Fitzpatrick D et al. (2008) Neuroscience, 4th edn. Sunderland, MA: Sinauer Associates.

Stein PSG, Grillner S, Selverston AI and Stuart DG (eds) (1997) Neurons, Networks, and Motor Behavior. Cambridge, MA: MIT Press.

Squire LR, Berg D, Bloom FE et al. (eds) (2008) Fundamental Neuroscience, 3th edn. San Diego: Academic Press.

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

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Berkowitz, Ari(Apr 2012) Motor Output from the Brain and Spinal Cord. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0000189.pub3]