ISOLATION OF INTRINSIC AND MOTOR MECHANISM OF THE MONKEY'S SPINAL CORD
ISOLATION OF INTRINSIC AND MOTOR MECHANISM OF THE MONKEY'S SPINAL CORD
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猴子脊髓的内在机制和运动机制的分离
DOI:
10.1152/jn.1941.4.5.388
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发表时间:
1941
影响因子:
2.5
通讯作者:
H. Howe
中科院分区:
文献类型:
--
作者:
S. S. Tower;D. Bodian;H. Howe
THE INTRINSIC MECHANISM of the spinal cord is compounded of nerve cells and nerve fibers: all the nerve fibers which both originate and terminate within the cord, and all the nerve cells giving rise to those fibers. The fibers in question for the most part compose the ground bundles or proprius system of the cord, running courses believed not to exceed seven segments up or down from their level of origin. But any of the long ascending fibers which send collaterals to the spinal grey matter must also be reckoned within the mechanism to the point, at least, where the last such collateral is given off. Correspondingly, the cells include small cells such as those in the substantia gelatinosa and the various sized association cells scattered throughout the grey which probably give rise only to intrinsic fibers, together with the larger cells which give rise to the long ascending systems but whose spinal collaterals enter into the system. Additionally, if any of the emerging ventral root fibers send recurrent (Golgi) collaterals back to the grey matter, then their cells of origin and fibers out to and including the collaterals form a part of the in. trinsic mech anism. Excluded are the long descending systems, the en tering fibers of the posterior roots, a. nd the cells a. nd fibers for the anterior roots when no collaterals are present.To isolate the entirety of the intrinsic mechanism of the cord would require transecting the neural axis at the end of the medulla and severing all posterior and anterior spinal roots. This is scarcely practicable. To isolate a portion of the mechanism requires, however, only a double transection of the cord (one section high, one section low), and severance of the roots between. If only the sensory roots be cut, the motor roots being left intact, a preparation might be obtained in which many problems of function and structure in the intrinsic cord mechanism could be investigated provided only that the isolated region of spinal cord survived. That it can survive both the considerable trauma of the operation and being so isolated for a period of months has already been demonstrated for puppies (Tower, 1937), and some of the problems have been examined. The present report deals with a repetition of the experiment on 3 nearly grown monkeys (Macaca mulatta), killed, however, after 10 d. ays or 2 weeks for chromatolysis studies on the isolated cord segments.