摘要:

15 cats were trained to cross a hurdle in a shuttle box when stimulated through a single bipolar electrode chronically implanted in the subthalamic, mesencephalic and most rostral pontine tegmentum. A lesion was then made through one or both electrode poles. Upon recovery, three patterns of response emerged: (1) crossing with higher threshold or longer latencies; (2) no crossing, or (3) no change in crossing. The response pattern correlated with the anatomic findings. The nine animals that crossed before but not after the lesion, showed either lesions or heavy axonal and terminal degeneration in the H2 field.

ISSN:0006-8977    

DOI:10.1159/000124399

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Following electrolytic lesions of the superior olivary nucleus (SO) of the bullfrog, Rana catesbeiana, the efferent pathways of this nucleus were studied with silver impregnation methods. The major projection was to the ipsilateral principal nucleus of the torus semicircularis. Less conspicuous degeneration was traced to the nuclei magnocellularis and commissuralis of the torus. No contribution was made to the tectum or nucleus isthmi. Other projections of the SO include a smaller contralateral projection to these same nuclei and to the ipsilateral nucleus lateralis profundus mesencephali. A system of connections between the acoustic nuclei was invariably interrupted with these lesions and the degeneration seen in the more dorsal acoustic areas was not entirely due to the destruction of SO neurons.

ISSN:0006-8977    

DOI:10.1159/000124400

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A morphometric analysis of the pyramidal tract''s relation to digital dexterity was performed on data from 69 mammals. The results show that the variation in digital dexterity among mammals corresponds most closely to the variation in place of termination of pyramidal tract fibers within the spinal cord, corresponds less closely to the variation in the size of the tract itself and its constituent fibers, and does not correspond reliably with any other feature yet reported. Since the termination of pyramidal tract fibers on or very near spinal motor neurons is a prerequisite even for the peculiar kind of dexterity seen in some non-primates (e.g., raccoon, kinkajou), this one feature alone seems to be a critical factor.

ISSN:0006-8977    

DOI:10.1159/000124401

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A morphometric analysis of the pyramidal tract''s relation to digital dexterity was performed on data from 69 mammals. The results show that the variation in digital dexterity among mammals corresponds most closely to the variation in place of termination of pyramidal tract fibers within the spinal cord, corresponds less closely to the variation in the size of the tract itself and its constituent fibers, and does not correspond reliably with any other feature yet reported. Since the termination of pyramidal tract fibers on or very near spinal motor neurons is a prerequisite even for the peculiar kind of dexterity seen in some non-primates (e.g., raccoon, kinkajou), this one feature alone seems to be a critical factor.

ISSN:0006-8977    

DOI:10.1159/000124402

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A morphometric analysis of the pyramidal tract''s relation to digital dexterity was performed on data from 69 mammals. The results show that the variation in digital dexterity among mammals corresponds most closely to the variation in place of termination of pyramidal tract fibers within the spinal cord, corresponds less closely to the variation in the size of the tract itself and its constituent fibers, and does not correspond reliably with any other feature yet reported. Since the termination of pyramidal tract fibers on or very near spinal motor neurons is a prerequisite even for the peculiar kind of dexterity seen in some non-primates (e.g., raccoon, kinkajou), this one feature alone seems to be a critical factor.

ISSN:0006-8977    

DOI:10.1159/000124403

出版商:S. Karger AG    

年代:1975

数据来源: Karger