Document Detail

Cardiovascular and single unit responses elicited by stimulation of the islands of Calleja and by changes in arterial pressure.
MedLine Citation:
PMID:  7812789     Owner:  NLM     Status:  MEDLINE    
Recent experiments in this laboratory have investigated the distribution of the nuclear protein Fos in the rat brain after unilateral electrical stimulation of the aortic depressor nerve and have revealed intense ipsilateral straining in the islands of Calleja. To test the hypothesis that the islands of Calleja may have a role in cardiovascular control, we tested the effect on arterial pressure and heart rate of microinjection of L-glutamate into the islands of Calleja of the artificially ventilated, urethane anesthetized rat. Microinjection of glutamate into the islands of Calleja resulted in a decrease in arterial pressure (24.5 +/- 1.5 mmHg) and heart rate (16.6 +/- 1.6 bpm). These responses were eliminated by i.v. injection of propranolol or by transection of the spinal cord at the C1 level. These results are the first demonstration that the islands of Calleja are involved in mediating cardiovascular reflexes primarily through an influence on sympathetic outflow to the heart and vessels. To determine the effects of increases or decreases of arterial pressure on single unit activity in the islands of Calleja, responses of single units in the islands to i.v. injection of phenylephrine or sodium nitroprusside were recorded. Of 87 units recorded from in the islands of Calleja, 40 (46%) responded to phenylephrine and 27 (68%) decreased their firing frequency. Of these 27, 16 (59.3%) increased their firing frequency to administration of nitroprusside. In addition, in 11 (31%) of 35 units recorded from in the islands, glutamate microinjection in the nucleus tractus solitarius decreased the firing frequency in 9 (82%) units.(ABSTRACT TRUNCATED AT 250 WORDS)
F R Calaresu; J Zhang; V C Chitravanshi; D J McKitrick
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Brain research     Volume:  655     ISSN:  0006-8993     ISO Abbreviation:  Brain Res.     Publication Date:  1994 Aug 
Date Detail:
Created Date:  1995-02-06     Completed Date:  1995-02-06     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0045503     Medline TA:  Brain Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  45-50     Citation Subset:  IM    
Department of Physiology, University of Western Ontario, London, Canada.
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MeSH Terms
Aorta / innervation,  physiology
Blood Pressure / physiology*
Electric Stimulation
Glutamic Acid / administration & dosage,  pharmacology
Hemodynamics / physiology*
Neurons / physiology*
Nitroprusside / pharmacology
Olfactory Bulb / cytology,  physiology*
Patch-Clamp Techniques
Phenylephrine / pharmacology
Pressoreceptors / physiology
Propranolol / pharmacology
Proto-Oncogene Proteins c-fos / metabolism
Rats, Wistar
Sympathetic Nervous System / drug effects,  physiology
Reg. No./Substance:
0/Proto-Oncogene Proteins c-fos; 15078-28-1/Nitroprusside; 525-66-6/Propranolol; 56-86-0/Glutamic Acid; 59-42-7/Phenylephrine

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