Focal Acidosis in the Pre-Bötzinger Complex Area of Awake Goats Induces a Mild Tachypnea

Authors

K. L. Krause, Medical College of Wisconsin
Hubert V. Forster, Medical College of Wisconsin
S. E. Davis, Medical College of WisconsinFollow
T. Kiner, Medical College of Wisconsin
Joshua M. Bonis, Medical College of Wisconsin
Lawrence Pan, Marquette UniversityFollow
B. Qian, Medical College of Wisconsin

Document Type

Article

Language

eng

Format of Original

10 p.

Publication Date

1-2009

Publisher

American Physiological Society

Source Publication

Journal of Applied Physiology

Source ISSN

0021-8987

Original Item ID

doi: 10.1152/japplphysiol.90547.2008

Abstract

There are widespread chemosensitive areas in the brain with varying effects on breathing. In the awake goat, microdialyzing (MD) 50% CO(2) at multiple sites within the medullary raphe increases pulmonary ventilation (Vi), blood pressure, heart rate, and metabolic rate (Vo(2)) (11), while MD in the rostral and caudal cerebellar fastigial nucleus has a stimulating and depressant effect, respectively, on these variables (17). In the anesthetized cat, the pre-Bötzinger complex (preBötzC), a hypothesized respiratory rhythm generator, increases phrenic nerve activity after an acetazolamide-induced acidosis (31, 32). To gain insight into the effects of focal acidosis (FA) within the preBötzC during physiological conditions, we tested the hypothesis that FA in the preBötzC during wakefulness would stimulate breathing, by increasing respiratory frequency (f). Microtubules were bilaterally implanted into the preBötzC of 10 goats. Unilateral MD of mock cerebral spinal fluid equilibrated with 6.4% CO(2) did not affect Vi, tidal volume (Vt), or f. Unilateral MD of 25 and 50% CO(2) significantly increased Vi and f by 10% (P < 0.05, n = 10, 17 trials), but Vt was unaffected. Bilateral MD of 6.4, 25, or 50% CO(2) did not significantly affect Vi, Vt, or f (P > 0.05, n = 6, 6 trials). MD of 80% CO(2) caused a 180% increase in f and severe disruptions in airflow (n = 2). MD of any level of CO(2) did not result in any significant changes in mean arterial blood pressure, heart rate, or Vo(2). Thus the data suggest that the preBötzC area is chemosensitive, but the responses to FA at this site are unique compared with other chemosensitive sites.

Comments

Journal of Applied Physiology, Vol. 106, No. 1 (January 2009): 241-250. DOI.

Recommended Citation

Krause, K. L.; Forster, Hubert V.; Davis, S. E.; Kiner, T.; Bonis, Joshua M.; Pan, Lawrence; and Qian, B., "Focal Acidosis in the Pre-Bötzinger Complex Area of Awake Goats Induces a Mild Tachypnea" (2009). Physical Therapy Faculty Research and Publications. 32.
https://epublications.marquette.edu/phys_therapy_fac/32