Interspecies Comparisons for the C3-C4 Propriospinal System: Unresolved Issues
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There are conflicting views on the functional importance of the system of C3-C4 propriospinal neurones in the macaque, although the two sets of observations from the opposing laboratories are actually quite similar, both making the system appear much weaker than its well-known equivalent in the cat One group asserts, mainly via evidence derived from experiments with strychnine, that this is a consequence simply of inhibition of the propriospinal neurone. However, we ague here that this judgement is premature and that much more needs to be known about the neurones involved and their connectivity before the analogy with the system in the cat is safe. This is particularly important because of a similar analogy which has been made with respect to measurements in human subjects.
KeywordsTranscranial Magnetic Stimulation Pyramidal Tract Experimental Brain Research Lateral Reticular Nucleus Interspecies Comparison
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- Alstermark, B., and Kummel, H., 1990, Transneuronal transport of wheatgerm agglutinin conjugated horseradish peroxidase into last order spinal interneurones projecting to acromio-and spinodeltoideus motoneurones in the cat. 1. Location of labelled interneurones and influence of synaptic activity on the transneuronal transportExperimental Brain Research80, 83–95.CrossRefGoogle Scholar
- Alstermark, B., Lindström, S., Lundberg, A., and Sybirska, E., 1981, Integration in descending motor pathways controlling the forelimb in the cat. 8. Ascending projection to the lateral reticular nucleus from C3–C4 propriospinal neurones also projecting to forelimb motoneuronesExperimental Brain Research42, C3–C4.CrossRefGoogle Scholar
- Alstermark, B., and Lundberg, A., The C3–C4 propriospinal system: target-reaching and food-taking, in:Muscle Afferents and Spinal Control of MovementL. Jami, E. Pierrrot-Deseilligny and D. Zytnicki, eds., Pergamon, Oxford, pp. C3–C4.Google Scholar
- Alstermark, B., Lundberg, A., and Sasaki, S., 1984b, Integration in descending motor pathways controlling the forelimb in the cat. 12. Interneurones which may mediate descending feed-forward inhibition and feedback inhibition from the forelimb to C3–C4 propriospinal neuronesExperimental Brain Research 56C3–C4CrossRefGoogle Scholar
- Holmqvist, B. and Lundberg, A., 1961, Differential supraspinal control of synaptic actions evoked by volleys in the flexion reflex afferents in alpha motoneuronesActa Physiologica Scandinavica54, suppl. 186.Google Scholar
- Lemon, R.N., Kirkwood, P.A., Maier, M.A., Nakajima, K., and Nathan, P., 2002, Direct and indirect pathways for corticospinal control of upper limb motoneurones in the primate, inBrain Mechanisms for the Integration of Posture and MovementS. Mori, D.G. Stuart, M. Wiesendanger, eds., Progress in Brain Research, Elsevier, Amsterdam (Submitted).Google Scholar
- Pauvert, V., Pierrot-Desilligny, E., and Rothwell, J.C., 1998, Role of spinal premotoneurones in mediating corticospinal input to forearm motoneurones in manJournal of Physiology508, 310–312.Google Scholar