Document Detail


Cerebellar fastigial nuclei activity during blood pressure challenges.
MedLine Citation:
PMID:  16690795     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The cerebellar fastigial nuclei (FN) assist in regulating compensatory responses to large blood pressure changes and show structural injury and functional impairment to cardiovascular challenges in syndromes with sleep-disordered breathing. The patterned time course of FN responses to elevation or lowering of blood pressure and location of responsive regions within the nuclei are unclear. We evaluated FN neural activity in six anesthetized rats using optical imaging procedures during elevation and lowering of arterial pressure by phenylephrine and nitroprusside, respectively. Hypertension diminished optical correlates of FN neural activity, while measures of activity increased to hypotension, with peak neural responses occurring 5-10 s later than peak blood pressure changes. Blood pressure responses were followed by heart rate changes, and peak respiratory rates developed even later, in close temporal proximity to FN activity patterns. Although overall topographical response trends were similar, regional patterns of altered neural activity appeared to both hypertension and hypotension. The extent of neural change was greater during recovery from hypertension than for hypotension at high-dose levels. Blood pressure levels saturated with increasing phenylephrine doses, while FN activity continued to decline. No saturation appeared in heart or respiratory rate trends. The findings suggest that the FN compensate for large blood pressure changes by sympathoexcitatory and inhibitory processes, which accompany late-developing somatic or respiratory adjustments.
Authors:
D M Rector; C A Richard; R M Harper
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2006-05-11
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  101     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2006 Aug 
Date Detail:
Created Date:  2006-07-19     Completed Date:  2006-09-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  549-55     Citation Subset:  IM    
Affiliation:
Dept. of Neurobiology, Univ. of California at Los Angeles, Los Angeles, CA 90095-1763, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Anoxia / physiopathology
Blood Pressure / drug effects,  physiology*
Cerebellar Nuclei / physiology*
Dose-Response Relationship, Drug
Heart Rate / physiology
Hypertension / physiopathology*
Hypotension / physiopathology*
Male
Nitroprusside / pharmacology
Phenylephrine / pharmacology
Rats
Respiration
Sleep Apnea, Obstructive / physiopathology
Time Factors
Vasoconstrictor Agents / pharmacology
Vasodilator Agents / pharmacology
Grant Support
ID/Acronym/Agency:
HL-22418/HL/NHLBI NIH HHS; MH-60263/MH/NIMH NIH HHS
Chemical
Reg. No./Substance:
0/Vasoconstrictor Agents; 0/Vasodilator Agents; 15078-28-1/Nitroprusside; 59-42-7/Phenylephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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