Spinal Terminations of the Projection Fibres From the Motor Cortex of Primates

Hoff, Ebbe Curtis; Hoff, H. E.

doi:10.1093/brain/57.4.454

Cited by 82 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sometimes collections of dendrites can be seen in the ganglia. In animals given neurotoxic drugs the abnormalities consist of swelling and argentophilia of neurones, axonal fragmentation, retraction balls, and dendritic masses which are probably swollen boutons terminaux (Hoff and Hoff, 1934) and neurofibrillary tangles probably representing hypertrophy of the autonomic ground plexus (Smith, 1968). In the animals given syrup of senna by mouth, there was little change for about a month.…”

Section: Resultsmentioning

confidence: 99%

Effect of irritant purgatives on the myenteric plexus in man and the mouse.

Smith¹

1968

Gut

192

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Effect of irritant purgatives on the myenteric plexus in man and the mouse.

Smith¹

1968

Gut

192

View full text Add to dashboard Cite

“…No significant monosynaptic pathway exists in the cat (Lloyd, 1941;Bernhard & Bohm, 1954b;Hern & Phillips, 1959). In the primates Hoff & Hoff (1934) claimed that there were more pyramidal boutons applied to motoneurones in the baboon than in the macaque, and more still in the chimpanzee. In the cat the pyramidal system operates largely by influencing the interneurones mediating the segmental reflexes (Lundberg & Voorhoeve, 1961).…”

Section: Discussionmentioning

confidence: 99%

Minimal synaptic actions of pyrimidal impulses on some alpha motoneurones of the baboon's hand and forearm

Landgren¹,

Phillips²,

Porter³

1962

The Journal of Physiology

198

View full text Add to dashboard Cite

The method of direct electrical stimulation of populations of pyramidal neurones by weak surface-anodal shocks (Hern, Landgren, Phillips & Porter, 1962) creates specially favourable conditions for reinvestigating the question whether pyramidal neurones are connected monosynaptically with alpha motoneurones in the spinal cord.The scope of experiment has been deliberately restricted to the 'arm area ' of the cortex and to the alpha motoneurones of the forearm and hand. The arm area was chosen partly because it is more readily exposed than the leg area, and partly because the range and precision of hand movements, even in the baboon, would lead one to expect a powerful cortical command of these final common paths. This expectation is supported by the fact that the cortical electrical threshold for hand movements is lower than the threshold for other movements (Liddell & Phillips, 1950, 1951. To detect minimal synaptic transmission by pyramidal impulses and to measure its quantity and timing, we have made intracellular records from alpha motoneurones innervating the forearm and hand. By thus restricting stimulus and response to their minima, and by attending only to the earliest responses, which are, in fact, the only responses to be recorded at all under these conditions, it is possible to be reasonably sure that one is dealing with pure pyramidal actions, uncomplicated by the so-called extrapyramidal effects that would inevitably be stirred up by stronger and more prolonged electrical stimulation. Experience of these delicate methods has justified our belief that the extra hazards of surgical isolation of the pyramidal pathway by transecting the hind brain, sparing only the medullary pyramids (Lloyd, 1941;Preston & Whitlock, 1960, 1961, can be avoided in these special circumstances.

show abstract

“…Early observations by Hoff et al showed that unilateral lesions to the PT resulted in extensive bouton degeneration in the contralateral spinal gray matter; however, minor degeneration was observed within the dorsal and ventral horns of ipsilateral gray suggesting the presence of ipsilateral pyramidal projections [37]. …”

Section: Icst In Non-human Primatesmentioning

confidence: 99%

Preclinical and Clinical Evidence on Ipsilateral Corticospinal Projections: Implication for Motor Recovery

Alawieh

Tomlinson

Adkins

et al. 2017

Transl. Stroke Res.

View full text Add to dashboard Cite

Motor impairment is the most common complication after stroke, and recovery of motor function has been shown to be dependent on the extent of lesion in the ipsilesional corticospinal tract (iCST) and activity within ipsilesional primary and secondary motor cortices. However, work from neuroimaging research has suggested a role of the contralesional hemisphere in promoting recovery after stroke potentially through the ipsilateral uncrossed CST fibers descending to ipsilateral spinal segments. These ipsilateral fibers, sometimes referred to as “latent” projections, are thought to contribute to motor recovery independent of the crossed CST. The aim of this paper is to evaluate using cumulative evidence from animal models and human patients on whether an uncrossed CST component is present in mammals and conserved through primates and humans, and whether iCST fibers have a functional role in hemiparetic/hemiplegic human conditions. This review highlights that an ipsilateral uncrossed CST exists in human during development, but the evidence on a functionally relevant iCST component in adult humans is still elusive. In addition, this review argues that whereas activity within the ipsilesional cortex is essential for enhancing motor recovery after stroke, the role of iCST projections specifically is still controversial. Finally, conclusions from current literature emphasize the importance of activity in the ipsilesional cortex and the integrity of crossed CST fibers as major determinants of motor recovery after brain injury.

show abstract

Spinal Terminations of the Projection Fibres From the Motor Cortex of Primates

Cited by 82 publications

References 0 publications

Effect of irritant purgatives on the myenteric plexus in man and the mouse.

Effect of irritant purgatives on the myenteric plexus in man and the mouse.

Minimal synaptic actions of pyrimidal impulses on some alpha motoneurones of the baboon's hand and forearm

Preclinical and Clinical Evidence on Ipsilateral Corticospinal Projections: Implication for Motor Recovery

Contact Info

Product

Resources

About