The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Stephen E. Glickman - One of the best experts on this subject based on the ideXlab platform.
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Sexual dimorphism of perineal muscles and motoneurons in spotted hyenas
The Journal of Comparative Neurology, 1996Co-Authors: Nancy G. Forger, Laurence G. Frank, S. Marc Breedlove, Stephen E. GlickmanAbstract:Female spotted hyenas are known for their male-like genitalia, high levels of aggression, and dominance over males, characteristics which are attributed to exposure to elevated levels of testosterone in utero. Although the nervous system of spotted hyenas has not previously been examined, one might predict that neural systems which are sexually dimorphic in other mammals would be monomorphic in this species. Spinal motoneurons which innervate muscles associated with the phallus are located in Onufs Nucleus and are more numerous in males than in females in a wide array of mammals. Onufs Nucleus was examined in adult and neonatal spotted hyenas and, contrary to expectation, was found to be sexually dimorphic in the typical mammalian pattern: Males have significantly more motoneurons in Onufs Nucleus than do females. This dimorphism was correlated with a previously undescribed dimorphism in the relevant target musculature. Specifically, the morphology of the bulbocavernosus muscle is distinctly different in male and female spotted hyenas. Pregnant hyenas were treated with anti-androgen in an attempt to interfere with the actions of androgen during fetal development. Motoneuron number in Onuf??s Nucleus and the morphology of the bulbocavernosus muscle were feminized in males exposed to anti-androgen in utero. © 1996 Wiley-Liss, Inc.
Ah Pullen - One of the best experts on this subject based on the ideXlab platform.
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Involvement of propriospinal paths subsequent to diphtheritic neuronopathy in Onuf's Nucleus.
1994Co-Authors: Ah PullenAbstract:Unilateral intramuscular injection of diphtheria toxin into the extenal anal sphincter of th cat produced the characteristic features of diphtheritic toxicity in ipsilateral pudendal motoneurones in Onufs Nucleus. Immunocytochemistry revealed abnormal phosphorylated neurofilament protein in intoxicated motoneurones. Wider examination also identified lesions in small diameter interneurones in laminae vii-viii, some large dimeter neurons in the sacral ventrolateral and ventro-medial nuclei projecting to pelvic floor muscles, and some small neurones oin L4-L7. Intramuscular injections of either collidal-gold-toxin conjugate of WGA=_HRp (trans-neuronal label) produced similar results, suggesting trans-neuronal spread of toxin and toxicitry via local segmetal interneuronal pathhways. Further evidence for this was obtained fololowing injections of toxin-conjugate or WGA-HRP into the anterior tibial muscle, and finding labelling of motoneurones in L4-7, but also small diameter interneurones in sacral segments, suggesting close synaptic lumbar-sacral coupling.
Nancy G. Forger - One of the best experts on this subject based on the ideXlab platform.
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Sexual dimorphism of perineal muscles and motoneurons in spotted hyenas
The Journal of Comparative Neurology, 1996Co-Authors: Nancy G. Forger, Laurence G. Frank, S. Marc Breedlove, Stephen E. GlickmanAbstract:Female spotted hyenas are known for their male-like genitalia, high levels of aggression, and dominance over males, characteristics which are attributed to exposure to elevated levels of testosterone in utero. Although the nervous system of spotted hyenas has not previously been examined, one might predict that neural systems which are sexually dimorphic in other mammals would be monomorphic in this species. Spinal motoneurons which innervate muscles associated with the phallus are located in Onufs Nucleus and are more numerous in males than in females in a wide array of mammals. Onufs Nucleus was examined in adult and neonatal spotted hyenas and, contrary to expectation, was found to be sexually dimorphic in the typical mammalian pattern: Males have significantly more motoneurons in Onufs Nucleus than do females. This dimorphism was correlated with a previously undescribed dimorphism in the relevant target musculature. Specifically, the morphology of the bulbocavernosus muscle is distinctly different in male and female spotted hyenas. Pregnant hyenas were treated with anti-androgen in an attempt to interfere with the actions of androgen during fetal development. Motoneuron number in Onuf??s Nucleus and the morphology of the bulbocavernosus muscle were feminized in males exposed to anti-androgen in utero. © 1996 Wiley-Liss, Inc.
Laurence G. Frank - One of the best experts on this subject based on the ideXlab platform.
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Sexual dimorphism of perineal muscles and motoneurons in spotted hyenas
The Journal of Comparative Neurology, 1996Co-Authors: Nancy G. Forger, Laurence G. Frank, S. Marc Breedlove, Stephen E. GlickmanAbstract:Female spotted hyenas are known for their male-like genitalia, high levels of aggression, and dominance over males, characteristics which are attributed to exposure to elevated levels of testosterone in utero. Although the nervous system of spotted hyenas has not previously been examined, one might predict that neural systems which are sexually dimorphic in other mammals would be monomorphic in this species. Spinal motoneurons which innervate muscles associated with the phallus are located in Onufs Nucleus and are more numerous in males than in females in a wide array of mammals. Onufs Nucleus was examined in adult and neonatal spotted hyenas and, contrary to expectation, was found to be sexually dimorphic in the typical mammalian pattern: Males have significantly more motoneurons in Onufs Nucleus than do females. This dimorphism was correlated with a previously undescribed dimorphism in the relevant target musculature. Specifically, the morphology of the bulbocavernosus muscle is distinctly different in male and female spotted hyenas. Pregnant hyenas were treated with anti-androgen in an attempt to interfere with the actions of androgen during fetal development. Motoneuron number in Onuf??s Nucleus and the morphology of the bulbocavernosus muscle were feminized in males exposed to anti-androgen in utero. © 1996 Wiley-Liss, Inc.
S. Marc Breedlove - One of the best experts on this subject based on the ideXlab platform.
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Sexual dimorphism of perineal muscles and motoneurons in spotted hyenas
The Journal of Comparative Neurology, 1996Co-Authors: Nancy G. Forger, Laurence G. Frank, S. Marc Breedlove, Stephen E. GlickmanAbstract:Female spotted hyenas are known for their male-like genitalia, high levels of aggression, and dominance over males, characteristics which are attributed to exposure to elevated levels of testosterone in utero. Although the nervous system of spotted hyenas has not previously been examined, one might predict that neural systems which are sexually dimorphic in other mammals would be monomorphic in this species. Spinal motoneurons which innervate muscles associated with the phallus are located in Onufs Nucleus and are more numerous in males than in females in a wide array of mammals. Onufs Nucleus was examined in adult and neonatal spotted hyenas and, contrary to expectation, was found to be sexually dimorphic in the typical mammalian pattern: Males have significantly more motoneurons in Onufs Nucleus than do females. This dimorphism was correlated with a previously undescribed dimorphism in the relevant target musculature. Specifically, the morphology of the bulbocavernosus muscle is distinctly different in male and female spotted hyenas. Pregnant hyenas were treated with anti-androgen in an attempt to interfere with the actions of androgen during fetal development. Motoneuron number in Onuf??s Nucleus and the morphology of the bulbocavernosus muscle were feminized in males exposed to anti-androgen in utero. © 1996 Wiley-Liss, Inc.
