THE BEHAVIOR OF CATS FOLLOWING BILATERAL REMOVAL OF THE ROSTRAL PORTION OF THE CEREBRAL HEMISPHERES

1938 ◽  
Vol 1 (1) ◽  
pp. 39-44 ◽  
Author(s):  
H. W. Magoun ◽  
S. W. Ranson
2004 ◽  
Vol 62 (2b) ◽  
pp. 406-412 ◽  
Author(s):  
José Eymard Homem Pittella ◽  
Sebastião Nataniel da Silva Gusmão

OBJECTIVE: A study was made of the brain lesions in 120 random victims of fatal road traffic accidents to determine the frequency and topographic distribution of diffuse axonal damage (DAI) in relation to the midline brain structures. METHOD: The identification of axons was carried out with a mouse antibody anti-neurofilament proteins 70-, 160-, and 210-kD. RESULTS: DAI was identified in 96 (80%) brains and classified as Grade 1 in 21.9%, as Grade 2 in 51%, and as Grade 3 in 27.1% of the patients. In spite of the diffuse distribution that is characteristic of DAI, damage occurred preferentially in the interhemispheric formations (corpus callosum and fornix) and rostral portion of the brainstem, usually to one side of the midline. CONCLUSION: From a mechanical point of view, the interhemispheric formations and the rostral portion of the brainstem act as fixating structures for the cerebral hemispheres during rotational acceleration of the head. It is known that the motion of the cerebral hemispheres is delayed at the points of fixation, where greater stress would be produced, particularly on the side subjected to greater displacement. The frequent involvement by DAI of deep, center-medial brain structures, usually to one side of the midline, supports the mechanism proposed above.


Author(s):  
Christine Chiarello ◽  
Kim Cannon ◽  
Lorie Richards ◽  
Lisa Maxfield

2011 ◽  
Vol 4 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Sergei V. Smirnov

Examination of the cranial morphology in Bombina orientalis (Anura: Discoglossidae) revealed the occurrence of additional dermal bones lying: a) between the nasals and frontoparietals, b) between frontoparietals, and c) on the tectum synoticum behind the frontoparietals. The presence of similar bones as well as extra ossifications lying in the midline in the rostral portion of skull was shown to be a rather common event among anurans. Based on the occurrence of bones with similar topology in crossopterygians and different stegocephalians, it was concluded that extra ossifications sporadically appearing in anurans are more likely to be ancient cranial elements than neomorphs. Additional dermal bones found in the anterior portion of the anuran skull are homologous to the postrostrals of crossopterygians; extra ossifications lying between the frontoparietals correspond to the bones with similar topology sporadically appearing in crossopterygians and stegocephalians; and extra bones situated behind the frontoparietals are homologous to the lateral extrascapulars (postparietals of stegocephalians) and the median extrascapular of crossopterygians. These extra bones were proposed to be inherited from the presumed common ancestor of all Gnathostomes and retained in anurans in the state of latent capacities. The sporadic appearance of these bones in anurans results from the phenotypical realization of these latent capacities.


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