Innervation of the medial rectus muscle in the ratfish,Hydrolagus colliei
โ Scribed by Puzdrowski, R.L.
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 315 KB
- Volume
- 400
- Category
- Article
- ISSN
- 0021-9967
No coin nor oath required. For personal study only.
โฆ Synopsis
Oculomotor organization in elasmobranch fish (sharks, skates, and rays) differs from that in other vertebrates in that the medial rectus muscle is innervated by contralateral rather than ipsilateral motoneurons. Distinguishing whether this innervation pattern is unique to the elasmobranchs, or is the ancestral pattern for cartilaginous fishes, requires examination of a representative of the sister group to the elasmobranchs, the holocephalans (ratfish). In the present study, the innervation pattern of the medial rectus was examined in a ratfish, Hydrolagus colliei, by using biotinylated dextran amines (BDA, 3,000 MW). Labeled cells were revealed in the contralateral oculomotor nucleus. Therefore, an innervation pattern in which the medial rectus muscle is innervated by contralateral motoneurons is the primitive condition for cartilaginous fishes.
๐ SIMILAR VOLUMES
Polyneural innervation was studied in the psoas muscle in developing rats from P4 till P25 and at adult age, with the combined silveracetylcholinesterase technique. Nerve endings were counted, and endplates were measured. These data were compared with such data in the human. The end of polyneural in
Background. Extramedullary involvement of acute lymphoblastic leukemia (ALL) in sites outside the central nervous system (CNS) or testes is rare and may signal a refractory form of leukemia. Methods. The authors describe a child with ALL who experienced a relapse involving the inferior rectus muscl
Contractile measures on 67 single muscle units in the cat lateral rectus muscle were made in response to motoneuron stimulation. Simultaneous activation of four to five additional units, using muscle nerve stimulation, allowed an examination of unit force summation. Linear force addition was found i
Morphometric and histochemical methods were used to estimate the force-developing capabilities and fiber-type contents of four muscle complexes (rhomboideus, levator scapulae, trapezius, and sternomastoideus) that link the shoulder girdle to the skull and cervical vertebrae. Each complex contained a