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Cerebellar Afferents from neurons in the extraocular motor nuclei: a fluorescent retrograde double-labeling study in the sheep
No full textThe fluorescent retrograde double labeling technique has been used to identify within the extraocular motor nuclei of the sheep the neurons projecting to the cerebellum and to provide evidence whether they are motor neurons sending collaterals to the cerebellum or a separate population of neurons. The study was performed on eight sheep. The fluorescent tracers used were Fast Blue and the diamidino yellow dihydrochloride. In one and the same animal a fluorescent tracer was injected into the extraocular muscles (EOMs) and the other into bilateral points of the vermal folia II-V and paramedian lobule, or into the vermal folia VI, VIIA and VIIB, or into the underlying fastigial nuclei. Within the oculomotor, trochlear, and abducens nuclei, almost all of the motor neurons were labeled by the tracer injected into the EOMs and only a few cells were fluorescent for the tracer infiltrated into the cerebellum. These latter labelings were present bilaterally, and their number and distribution did not show apparent differences after injecting the paramedian lobule and the vermal folia or the fastigial nucleus. Along the rostrocaudal extent of the oculomotor and trochlear nuclei, the neurons projecting to the cerebellum were intermingled with the motor neurons located in the nuclear area facing the medial longitudinal fasciculus. In the abducens nucleus they were restricted to the caudal pole of the nucleus, which is located ventrolaterally to the genu of the facial nerve. Double-labeled neurons were never found. The absence of double-labeled cells, in spite of the efficiency of the tracer infiltration into the EOMs and into the cerebellum, demonstrates that the cerebellar projections from the extraocular motor nuclei are not collaterals of the motor neurons, but axons of a separate population of neurons. [...
ANALYSIS OF THE STERNOTRACHEALIS MUSCLE-FIBERS IN SOME ANSERIFORMES - HISTOCHEMISTRY AND SEX-DIFFERENCES
No full textDifferent intrafusal fiber composition of spindles in sheep and pig extraocular muscles.
No full textNerve fiber composition of the intracranial portion of the oculomotor, trochlear, and abducens nerves in the sheep
No full textIn the present investigation, the fiber content and the diameter spectra of the intracranial portion of the three oculomotor nerves (oculomotor, trochlear, and abducens nerves) were analysed in sheep by light and electron microscopy. It was determined that up to 14.98% of fibers in the oculomotor nerve, 17.01% in the trochlear nerve, and 11.87% in the abducens nerve were unmyelinated. The myelinated fibers showed a bimodal distribution in their size spectrum in all three nerves, with a majority of large myelinated axons, but a considerable proportion of small myelinated fibers, as well. The sensory function of the unmyelinated fibers present in the three oculomotor nerves is discussed also on the basis of our previous morphofunctional investigations. Anat Rec 260:294-298, 2000. (C) 2000 Wiley-Liss, Inc.[...
Sex differences in the histochemical characteristics of the sternotrachealis muscle of the duck.
No full textAN IMMUNOHISTOCHEMICAL APPROACH TO THE INTRAFUSAL FIBERS OF EXTRAOCULAR-MUSCLE SPINDLES IN SHEEP, COW, AND PIG
No full textSelective deafferentation of hand cutaneous territory is followed by changes in fibre type distribution of a forearm muscle in the horse.
No full textBased on previous observations that capsaicin can selectively damage group III and IV afferents and induce muscle fibre transformation, we hypothesized that eliminating, by means of capsaicin, the group III and IV afferents of a peripheral territory it could lead to a fibre transformation in a muscle involved in the flexor reflexes of the same peripheral territory. Therefore, capsaicin was injected into the palmar nerves of the forelimb of the horse to investigate if eliminating group III and IV afferents from the hand of the horse a muscle fibre transition would occur in the flexor carpi radialis (FCR) muscle, which is involved in the flexor reflexes of the finger itself. 120 days after capsaicin injection, type I slow fibres increased and type IIA fast fibres decreased. We presume that the long lasting deafferentation of the ergo-nociceptive fibres causes a plastic remodelling in the central nervous system and indirectly influences the motoneuron excitability via short or long loop-pathways enhancing their tonic discharge
[Determination of the peripheral field of several trigeminal afferent fibers present in the oculomotor nerve].
No full textSIMULTANEOUS CELL-DEATH IN THE TRIGEMINAL GANGLION AND IN GANGLION NEURONS PRESENT IN THE OCULOMOTOR NERVE OF THE BOVINE FETUS
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