Show simple item record

dc.contributor.authorDerojas, Teresa C.
dc.date.accessioned2020-11-01T21:50:38Z
dc.date.available2020-11-01T21:50:38Z
dc.date.issued1989-04
dc.identifier.urien
dc.identifier.urihttp://hdl.handle.net/10675.2/623658
dc.description.abstractStudies were conducted to determine if a selectjv~ vulnerability irrespective of axonal size occurs in the CNS with acrylamide {ACR} and in the PNS with another toxicant, 2,5-hexanedione {HD). In these studies two new and effective HD cat models have been introduced, the osmotic minipump and the subcutaneous injection models.. These models have an advantage ove~ the drinking water model previously used in that the rate of toxicant administration can be tightly controlled. By studying the behavioral consequences of HD intoxication it was. determined that the rate of toxicant administration is important in attaining a given behavioral deficit~ This contradicts previous reports. whi<:h. suggest that total HD dose,, and not the rate of toxicant administration, was the factor responsible for the behavioral and morphological changes· observed in HP toxicity •. These studies have added to the growing body of evidence. which directly opposes the classical hypothesis of selective vulnerability of axons in DA by suggesting that the largest diameter axons are not the most vulnerable to toxicant-induc·ed DA. In these studies smaller diameter axons were shown to be more vulnerable than the.largest diameter axons in the CNS utilizing ACR as the model toxicant, and in the peripheral nervous system utilizing HD. ACR impaired the ability to evoke a dorsal root reflex from the sural nerve {medium diameter) but not from the medial gastrocnemious nerve {largest diameter). HD affected the lengthfrequency response relationship. of secondary muscle spindle {Group II) to a greater extent than the primary muscle spindle (Group I). In addition, electron microscopic investigation of peripheral nerves from animals intoxicated with HD showed that unmyelinated fibers were undergoing degenerative changes at the same doses as myelinated axons of all diameters. An alternate hypothesis of selective vulnerability of slowly adapting systems in preference to rapidly adapting systems was also investigated. In these studies of primary muscle spindle afferent function (position and velocity sensitivity) and differential effect of HD on these two systems was not found. These data also suggested that a defect in muscle spindle afferent activity was not the genesis ·of the ataxia and motor incoordination induced by HD toxicity as was previously thought.en_US
dc.language.isoen_USen_US
dc.publisherAugusta Universityen_US
dc.rightsCopyright protected. Unauthorized reproduction or use beyond the exceptions granted by the Fair Use clause of U.S. Copyright law may violate federal law.en_US
dc.subjectacrylamideen_US
dc.subject2.5-hexanedioneen_US
dc.subjectdistal axonopathyen_US
dc.titleSelective vulnerability of axonal systems to acrylamide and 2,5-hexanedione toxicityen_US
dc.typeThesisen_US
dc.contributor.departmentDepartment of Pharmacology and Toxicologten_US
dc.description.advisorGoldstein, Barry D.
dc.description.degreeDoctor of Philosophyen_US
dc.description.committeeN/A, N/A
dc.embargoen
refterms.dateFOA2020-11-01T21:50:38Z


Files in this item

Thumbnail
Name:
deRojas_Teresa_PhD_1989.pdf
Size:
5.616Mb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record