PURL
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Title:
RECONSTITUTION OF THE URODELE SPINAL CORD FOLLOWING UNILATERAL ABLATION - II. REGENERATION OF THE LONGITUDINAL TRACTS AND EXTOPIC SYNAPTIC UNIONS OF THE MAUTHNER'S FIBERS ( PARTIAL DOCUMENT )
Document Location:
Location - DOE/NNSA NUCLEAR TESTING ARCHIVE Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - NTA@NV.DOE.GOV
Document Type:
JOURNAL ARTICLE
Publication Date:
1952 Mar 31
Declassification Status:
Never classified
Accession Number:
NV0702338
OpenNet Entry Date:
1994 Aug 27
OpenNet Modified Date:
2017 Dec 21
Description/Abstract:
THIS PAPER DISCUSSES THE RECONSTITUTION OF THE URODELE SPINAL CORD FOLLOWING UNILATERAL ABLATION. UNILATERAL ABLATION OF THE PROSPECTIVE BRACHIAL SPINAL CORD IN THE NEURULA INVOLVED REMOVAL OF APPROXIMATELY HALF THE NEURAL CREST. NEVERTHELESS REGULATION OF THE REMAINING CREST CELLS EVENTUATED IN ESSENTIALLY NORMAL SPINAL GANGLIA, PIGMENT AND SHEATH CELLS. MEDIALLY REGENERATED DORSAL ROOTS DISPLAYED A PREDILECTION FOR THE DORSAL ASPECTS OF THE MARGINAL AREAS. MOST FREQUENTLY THESE FIBERS ENTERED THE SENSORY FUNICULAR AREAS DIRECTLY. ENTRANCE OF THE DORSAL ROOTS INTO MOTOR FUNICULI WAS FOLLOWED BY DORSAL DEFLECTION OF THE FIBERS IN THE MARGINAL AREA, RESULTING IN RE- ESTABLISHMENT OF PROPER TOPOGRAPHICAL RELATIONSHIPS. FUNCTIONAL TESTS INDICATED THAT REGENERATED DORSAL ROOTS PROPERLY ACTIVATED THE SPINAL COORDINATION CENTER. IPSILATERAL CUTANEOUS SENSIBILITIES WERE INVARIABLY RESTORED. IN OTHER CASES WHEN THE RIGHT ROOT ENTERED THE LEFT SENSORY FUNICULUS, STIMULATION OF THE RIGHT LIMB ELICITED APPROPRIATE RESPONSES BUT IN THE LEFT LIMB. REGENERATED LONGITUDINAL FIBERS IN MANY CASES WERE NOT APPLIED TO THE GREY. SUCH ISOLATED CABLES INDICATED THAT THE POSTERIOR ELONGATION OF MOTOR FUNICULAR FIBERS AND THE DEVELOPMENT OF ASCENDING AND DESCENDING SENSORY FUNICULAR FIBER, OCCURRED INDEPENDENTLY OF LOCAL SURFACE CONDITIONS IN THE MANTLE. REGENERATED M-AXONS, ESPECIALLY IN THE EARLY GROUPS, INDICATED THE AXON WAS RESPONDING TO MICROSCOPIC CUES IN ITS SURROUNDINGS BY: (1) COURSING IN ITS NORMAL LOCATION POSTERIOR TO THE OPERATED REGION; (2) RETURNING TO PROPER POSITION AFTER RUNNING IN AN ISOLATED CABLE, AND (3) RUNNING WITH THE NORMAL CONTRALATERAL M-AXON FOLLOWING A SECONDARY DECUSSATION IN THE OPERATED REGION. BEHAVING ATYPICALLY, THE GIANT AXON WAS GENERALLY LOCATED IN THE VENTRAL FUNICULUS, THOUGH IN THE PERIPHERAL REACHES OF THE MARGINAL AREA.