HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 296/6/H1758    most recent 01045.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Diedrich, A. Articles by Furlan, R. PubMed PubMed Citation Articles by Diedrich, A. Articles by Furlan, R.

Lateralization of expression of neural sympathetic activity to the vessels and effects of carotid baroreceptor stimulation

¹Division of Clinical Pharmacology, Department of Medicine, Autonomic Dysfunction Center, Vanderbilt University, Nashville, Tennessee; and ²Department of Technologies for Health, Galeazzi Orthopaedic Institute, University of Milan, Milan; ³University of Milan, Milan; ⁴Internal Medicine "Bolognini" Hospital, Seriate, Bergamo; and ⁵Department of Bioengineering, Politecnico of Milan, Milan, Italy

Submitted 30 September 2008 ; accepted in final form 24 March 2009

Human studies suggest that cardiovascular neural sympathetic control is predominantly modulated by the right cerebral hemisphere. It is unknown whether post-ganglionic sympathetic activity [muscle sympathetic nerve activity (MSNA)] shows any functional asymmetry. Eight right-handed volunteers (3 women and 5 men, 32 ± 2 yr of age) underwent ECG, beat-by-beat blood pressure, respiratory activity, and simultaneous right and left MSNA recordings during spontaneous and controlled breathing (CB, 15 breaths/min, 0.25 Hz). Dynamic carotid baroreceptor stimulation was obtained by 0.1-Hz sinusoidal suction, from 0 to –50 mmHg, randomly applied to the right, left, and combined right and left sides of the neck during CB. Laterality was assessed by changes in the MSNA burst rate (in bursts/min, and bursts/100 beats), strength [amplitude (A) and area (AA)], and the oscillatory component at 0.1 Hz during baroreceptor stimulation. Amplitude parameters were normalized by CB burst mean amplitude and area of the same side. At rest, the right and left MSNA burst rate and total MSNA activity were similar. Conversely, the right MSNA normalized burst A_N (1.36 ± 0.18) and AA_N (1.31 ± 0.16) were larger than the left MSNA A_N (1.04 ± 0.09) and AA_N (1.02 ± 0.08). Unilateral and bilateral carotid baroreflex stimulation abolished the right prevalence of A_N and AA_N. In conclusion, the right lateralization of sympathetic activity to the vessels is indicated by normalized burst strength parameters of bilateral MSNA recordings at rest during spontaneous breathing. Carotid baroreceptor stimulation disrupted such expression of MSNA lateralization possibly by disturbing the synchronizing action of right cerebral hemisphere.

sympathetic control of circulation; muscle sympathetic nerve activity recording; burst amplitude; area; laterality