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: 296/4/H1157    most recent 01219.2008v1 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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tsuchimochi, H. Articles by Kaufman, M. P. Search for Related Content PubMed PubMed Citation Articles by Tsuchimochi, H. Articles by Kaufman, M. P.

Both central command and exercise pressor reflex activate cardiac sympathetic nerve activity in decerebrate cats

Pennsylvania State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania

Submitted 19 November 2008 ; accepted in final form 19 February 2009

Both static and dynamic exercise are known to increase cardiac pump function as well as arterial blood pressure. Feedforward control by central command and feedback control by the exercise pressor reflex are thought to be the neural mechanisms causing these effects during exercise. It remains unknown as to how each mechanism activates cardiac sympathetic nerve activity (CSNA) during exercise, especially at its onset. Thus we examined the response of CSNA to stimulation of the mesencephalic locomotor region (MLR, i.e., central command) and to static muscle contraction of the triceps surae muscles or stretch of the calcaneal tendon in decerebrate cats. We found that MLR stimulation immediately increased CSNA, which was followed by a gradual increase in heart rate, mean arterial pressure, and ventral root activity in a stimulus intensity-dependent manner. The latency of the increase in CSNA from the onset of MLR stimulation ranged from 67 to 387 ms. Both static contraction and tendon stretch also rapidly increased CSNA. Their latency from the development of tension in response to ventral root stimulation ranged from 78 to 670 ms. These findings suggest that both central command and the muscle mechanoreflex play a role in controlling cardiac sympathetic outflow at the onset of exercise.

mechanoreflex; renal sympathetic nerve activity; group III and IV afferents

This article has been cited by other articles:

				V. Gerovasili, E. Tripodaki, E. Karatzanos, T. Pitsolis, V. Markaki, D. Zervakis, C. Routsi, C. Roussos, and S. Nanas Short-term Systemic Effect of Electrical Muscle Stimulation in Critically Ill Patients Chest, November 1, 2009; 136(5): 1249 - 1256. [Abstract] [Full Text] [PDF]