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Anatomic patterning in the expression of vestibulosympathetic reflexesTo investigate the possibility that expression of vestibulosympathetic reflexes (VSR) is related to a nerve's anatomic location rather than its target organ, we compared VSR recorded from the same type of postganglionic fiber [muscle vasoconstrictor (MVC)] located at three different rostrocaudal levels: hindlimb, forelimb, and face. Experiments were performed on chloralose-anesthetized cats, and vestibular afferents were stimulated electrically. Single MVC unit activity was extracted by spike shape analysis of few-fiber recordings, and unit discrimination was confirmed by autocorrelation. Poststimulus time histogram analysis revealed that about half of the neurons were initially inhibited by vestibular stimulation (type 1 response), whereas the other MVC fibers were initially strongly excited (type 2 response). MVC units with types 1 and 2 responses were present in the same nerve fascicle. Barosensitivity was equivalent in the two groups, but fibers showing type 1 responses fired significantly faster than those giving type 2 responses (0.29 +/- 0.04 vs. 0.20 +/- 0.02 Hz). Nerve fibers with type 1 responses were most common in the hindlimb (21 of 29 units) and least common in the face (2 of 11 units), the difference in relative proportion being significant (P < 0.05, chi(2) test). These results support the hypothesis that VSR are anatomically patterned.
Document ID
20040141481
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Kerman, I. A.
(University of Melbourne Parkville, Victoria 3052, Australia)
Yates, B. J.
McAllen, R. M.
Date Acquired
August 22, 2013
Publication Date
July 1, 2000
Publication Information
Publication: American journal of physiology. Regulatory, integrative and comparative physiology
Volume: 279
Issue: 1
ISSN: 0363-6119
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: RO1-DC-00693
CONTRACT_GRANT: PO1-DC-03417
CONTRACT_GRANT: RO1-DC-03732
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Neuroscience

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