PMID- 9490856
OWN - NLM
STAT- MEDLINE
DCOM- 19980529
LR  - 20190512
IS  - 0022-3751 (Print)
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 508 ( Pt 1)
IP  - Pt 1
DP  - 1998 Apr 1
TI  - Role of spinal premotoneurones in mediating corticospinal input to forearm 
      motoneurones in man.
PG  - 301-12
AB  - 1. Evidence was sought to support the suggestion that corticospinal input can be 
      relayed to motoneurones (MNs) via a population of interneurones (premotoneurones) 
      in the cervical cord, and that this pathway operates in parallel with the direct 
      monosynaptic pathway. 2. Single motor units were recorded in forearm muscles and 
      post-stimulus time histograms (PSTHs) of their firing pattern were constructed 
      during voluntary activation. Weak transcranial magnetic stimulation of the 
      contralateral motor cortex was used to produce a small facilitation in the PSTH. 
      We then examined how the size of this peak was affected by low threshold 
      electrical stimulation of either the homonymous muscle nerve or the 
      musculo-cutaneous nerve at various interstimulus intervals (ISIs). 3. Homonymous 
      nerve stimulation had the following characteristics: (a) the cortical peak was 
      facilitated when stimuli were timed so that both inputs arrived simultaneously at 
      the MN; (b) the amount of facilitation was only slightly greater than the sum of 
      the effects of each stimulus given alone; and (c) facilitation affected even the 
      earliest bins of the cortically evoked peak. These three features are consistent 
      with a monosynaptic input onto the MN from both sources. 4. Stimulation of the 
      musculo-cutaneous nerve (which has no monosynaptic connections with forearm MNs) 
      had no effect at similar timings. It (a) produced facilitation only at longer 
      intervals corresponding to an extra central delay of 4-6 ms; (b) always gave a 
      significantly larger facilitation than expected from the algebraic sum of the 
      effects of each stimulus given alone; and (c) never affected the earliest bins of 
      the cortical peak. These features are compatible with interaction of peripheral 
      and cortical inputs at a population of premotoneurones. 5. These results confirm 
      the suggestion that premotoneurones mediate part of the cortical command to MNs 
      innervating forearm muscles. 6. Excitation is followed by an inhibition which may 
      almost completely suppress the cortical peak. It is suggested that cortical and 
      musculo-cutaneous volleys also converge onto inhibitory interneurones projecting 
      to the premotoneuronal pool.
FAU - Pauvert, V
AU  - Pauvert V
AD  - Laboratoire de Neurophysiologie Clinique, Reeducation, Hopital de la Salpetriere, 
      47 boulevard de l'Hopital, F-75651 Paris cedex 13, France.
FAU - Pierrot-Deseilligny, E
AU  - Pierrot-Deseilligny E
FAU - Rothwell, J C
AU  - Rothwell JC
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
SB  - IM
MH  - Adult
MH  - Cortical Spreading Depression/physiology
MH  - Electric Stimulation
MH  - Forearm/*innervation
MH  - Functional Laterality
MH  - Humans
MH  - Magnetics
MH  - Middle Aged
MH  - Motor Activity/*physiology
MH  - Motor Cortex/*physiology
MH  - Motor Neurons/*physiology
MH  - Movement/physiology
MH  - Muscle, Skeletal/*innervation
MH  - Skin/innervation
MH  - Spinal Cord/*physiology
MH  - Synapses/physiology
MH  - Synaptic Transmission/physiology
PMC - PMC2230869
EDAT- 1998/06/06 00:00
MHDA- 1998/06/06 00:01
PMCR- 1999/04/01
CRDT- 1998/06/06 00:00
PHST- 1998/06/06 00:00 [pubmed]
PHST- 1998/06/06 00:01 [medline]
PHST- 1998/06/06 00:00 [entrez]
PHST- 1999/04/01 00:00 [pmc-release]
AID - 10.1111/j.1469-7793.1998.301br.x [doi]
PST - ppublish
SO  - J Physiol. 1998 Apr 1;508 ( Pt 1)(Pt 1):301-12. doi: 
      10.1111/j.1469-7793.1998.301br.x.