Projection of cervical dorsal root fibers to the medulla oblongata in the brush‐tailed possum, <i>Trichosurus vulpecula</i>

Culberson, James L.

doi:10.1002/aja.1001790305

Cited by 5 publications

(1 citation statement)

References 33 publications

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“…So far. the emphasis of the studies on the ECN in rodents has been on the specific pro jections from neck muscles [Mysicka and Zenker, 1981;Ammann et al, 1983] or focused much on the segmental connections of ECN [Basbaum and Hand, 1973;Imamura el al., 1986: Culberson. 1987: Pfaller and Arvidsson.…”

Section: Introductionmentioning

confidence: 99%

Musculotopic Organization of Muscle Afferents in the External Cuneate Nucleus of the Gerbil as Revealed by Transganglionic Transport of Horseradish Peroxidase

Lan

Wen²,

Shieh³

1994

Cells Tissues Organs

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The projections of muscle afferents from six regions (hand, forearm, arm, thorax, shoulder and neck) to the external cuneate nucleus (ECN) of gerbils were investigated using transganglionic transport of horseradish peroxidase (HRP). These were chiefly ipsilateral projections which terminated in six discrete longitudinal columns in the ECN. A medial cell column confined to the caudal ECN received projections from the hand muscles, while the ventromedial and ventro-lateral cell columns in the posterior half of the ECN received projections from the forearm and arm muscles respectively. In the caudal ECN, the thoracic and shoulder muscles were represented by the dorsomedial and dorsolateral cell columns respectively. The last mentioned two columns extended anteriorly into the rostral ECN occupying a dorsal and intermediate portion leaving the ventral portion which represented the neck muscles. The latter also extended posteriorly into the middle 1/3 of ECN occupying a lateral portion. Serial sections and reconstruction studies showed that the ECN was located in the dorsal region of the upper medulla, approximately 0.3–1.8 mm rostral to the obex. The rostro-caudal extent of the six cell columns from hand proximally to neck were measured to be 0.5–0.8, 0.3–1.1, 0.3–1.3, 0.4–1.8, 0.4–1.8 and 0.8–1.8 mm rostral to the obex.

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Section: Introductionmentioning

confidence: 99%

Musculotopic Organization of Muscle Afferents in the External Cuneate Nucleus of the Gerbil as Revealed by Transganglionic Transport of Horseradish Peroxidase

Lan

Wen²,

Shieh³

1994

Cells Tissues Organs

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Central distribution of cervical primary afferents in the rat, with emphasis on proprioceptive projections to vestibular, perihypoglossal, and upper thoracic spinal nuclei

Neuhuber¹,

Zenker²

1989

J of Comparative Neurology

251

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The projections of primary afferents from rostral cervical segments to the brainstem and the spinal cord of the rat were investigated by using anterograde and transganglionic transport techniques. Projections from whole spinal ganglia were compared with those from single nerves carrying only exteroceptive or proprioceptive fibers. Injections of horseradish peroxidase (HRP) or wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) were performed into dorsal root ganglia C2, C3, and C4. Free HRP was applied to the cut dorsal rami C2 and C3, greater occipital nerve, sternomastoid nerve, and to the C1/2 anastomosis, which contains afferents from suboccipital muscles and the atlanto-occipital joint. WGA-HRP injections into ganglia C7 and L5 were performed for comparative purposes. Injections of WGA-HRP or free HRP into rostral cervical dorsal root ganglia and HRP application to C2 and C3 dorsal rami produced labeling in dorsal and ventral horns at the level of entrance, the central cervical nucleus, and in external and main cuneate nuclei. From axons ascending to pontine and descending to upper thoracic spinal levels, medial collaterals were distributed to medial and descending vestibular, perihypoglossal and solitary nuclei, and the intermediate zone and Clarke's nucleus dorsalis in the spinal cord. Lateral collaterals projected mainly to the trigeminal subnucleus interpolaris and to lateral spinal laminae IV and V. Results from HRP application to single peripheral nerves indicated that medial collaterals were almost exclusively proprioceptive, whereas lateral collaterals were largely exteroceptive with a contribution from suboccipital proprioceptive fibers. WGA-HRP injections into dorsal root ganglia C7 and L5 failed to produce significant labeling within vestibular and periphypoglossal nuclei, although they demonstrated classical projection sites within the brainstem and spinal cord. The consistent collateralisation pattern of rostral cervical afferents along their whole rostrocaudal course enables them to contact a variety of precerebellar, vestibulospinal, and preoculomotor neurons. These connections reflect the well-known significance of proprioceptive neck afferents for the control of posture, head position, and eye movements.

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Central projections of cervical primary afferent fibers in the guinea pig: An HRP and WGA/HRP tracer study

Prihoda

Hiller

Mayr

1991

J of Comparative Neurology

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The central course and the projections of the first and the second cervical dorsal root ganglia and of suboccipital muscle primary afferent fibers in the guinea pig were studied by means of anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA/HRP) or aqueous solution of horseradish peroxidase (HRP). Injections of WGA/HRP into the second cervical dorsal root ganglion produced labeling in the dorsal and ventral horns. Within the spinal cord, the largest amount of HRP reaction product was found within the lateral third of the substantia gelatinosa and within the central cervical nucleus. The main area of termination in the medulla was the external cuneate nucleus. However, HRP reaction product was also found within the medial and inferior vestibular nuclei, cell group x, the perihypoglossal nuclei, the nucleus of the solitary tract, and the nucleus of the spinal trigeminal tract. Descending fibers could be detected as caudal as spinal segment T5. Injections of WGA/HRP into the first cervical dorsal root ganglion produced heavy terminal label within the central cervical nucleus but not within the substantia gelatinosa. Again, the external cuneate nucleus was the main area of termination within the medulla. Label could not be observed within the vestibular nuclear complex or within the spinal trigeminal nucleus. Injections of aqueous HRP into the suboccipital muscles produced heavy transganglionic label within the central cervical nucleus, whereas the substantia gelatinosa totally lacked terminal label. Ascending proprioceptive fibers reached the external cuneate nucleus and group x. Scanty projections could be detected within the vestibular nuclei as well as within the perihypoglossal nuclei except for the nucleus prepositus hypoglossi. Label was absent in the spinal trigeminal nucleus.

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Projection of cervical dorsal root fibers to the medulla oblongata in the brush‐tailed possum, Trichosurus vulpecula

Cited by 5 publications

References 33 publications

Musculotopic Organization of Muscle Afferents in the External Cuneate Nucleus of the Gerbil as Revealed by Transganglionic Transport of Horseradish Peroxidase

Musculotopic Organization of Muscle Afferents in the External Cuneate Nucleus of the Gerbil as Revealed by Transganglionic Transport of Horseradish Peroxidase

Central distribution of cervical primary afferents in the rat, with emphasis on proprioceptive projections to vestibular, perihypoglossal, and upper thoracic spinal nuclei

Central projections of cervical primary afferent fibers in the guinea pig: An HRP and WGA/HRP tracer study

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