Projections of the carotid sinus nerve to the medulla in the dog

1987 ◽  
Vol 18 (3) ◽  
pp. 437-445 ◽  
Author(s):  
Cheryl L. Chernicky ◽  
Karen L. Barnes ◽  
Carlos M. Ferrario ◽  
John P. Conomy
Keyword(s):  
Carotid Sinus ◽  
Carotid Sinus Nerve

Effect of a synthetic progestin on ventilatory response to hypoxia in anesthetized rats

1989 ◽  
Vol 67 (5) ◽  
pp. 1754-1758 ◽  
Author(s):  
H. Kimura ◽  
M. Mikami ◽  
T. Kuriyama ◽  
Y. Fukuda
Keyword(s):  
Regulatory Mechanism ◽  
Carotid Sinus ◽  
Ventilatory Response ◽  
Break Point ◽  
Male Rat ◽  
Carotid Sinus Nerve ◽  
Ventilatory Responses ◽  
Chlormadinone Acetate ◽  
Ventilatory Depression ◽  
Ventilatory Response To Hypoxia

Effects on ventilatory responses to progressive isocapnic hypoxia of a synthetic potent progestin, chlormadinone acetate (CMA), were determined in the halothane-anesthetized male rat. Ventilation during the breathing of hyperoxic gas was largely unaffected by treatment with CMA when carotid chemoreceptor afferents were kept intact. The sensitivity to hypoxia evaluated by hyperbolic regression analysis of the response curve did not differ between the control and CMA groups. The reduction of ventilation after bilateral section of the carotid sinus nerve (CSN) in hyperoxia was less severe in CMA-treated than in untreated animals. Furthermore, the CMA-treated rats showed a larger increase in ventilation during the hypoxia test and a lower PO2 break point for ventilatory depression. Inhibition of hypoxic ventilatory depression by CMA persisted even after the denervation of CSN. We conclude that exogenous progestin likely protects regulatory mechanism(s) for respiration against hypoxic depression through a stimulating action independent of carotid chemoreceptor afferents and without a change in the sensitivity of the ventilatory response to hypoxia.

Time-dependent phrenic nerve responses to carotid afferent activation: intact vs. decerebellate rats

1993 ◽  
Vol 265 (4) ◽  
pp. R811-R819 ◽  
Author(s):  
F. Hayashi ◽  
S. K. Coles ◽  
K. B. Bach ◽  
G. S. Mitchell ◽  
D. R. McCrimmon
Keyword(s):  
Phrenic Nerve ◽  
Carotid Sinus ◽  
Carotid Sinus Nerve ◽  
Short Term ◽  
Nerve Activity ◽  
A Value ◽  
Afferent Activation ◽  
Term Potentiation ◽  
Long Term Facilitation

The objectives were to determine 1) respiratory responses to carotid chemoreceptor inputs in anesthetized rats and 2) whether the cerebellar vermis plays a role in these responses. A carotid sinus nerve was stimulated (20 Hz) with five 2-min trains, each separated by approximately 3 min. During stimulation, respiratory frequency (f), peak amplitude of integrated phrenic nerve activity (integral of Phr), and their product (f x integral of Phr) immediately increased. As stimulation continued, integral of Phr progressively increased to a plateau [short-term potentiation (STP)], but f and f x integral of Phr decreased [short-term depression (STD)] to a value still above control. Upon stimulus termination, integral of Phr progressively decreased but remained above control; f and f x integral of Phr transiently decreased below baseline. After the final stimulation, integral of Phr remained above control for at least 30 min [long-term facilitation (LTF)]. Repeated 5-min episodes of isocapnic hypoxia also elicited STP, STD, and LTF. Vermalectomy lowered the CO2-apneic threshold and eliminated LTF. In conclusion, carotid chemoreceptor activation in rats elicits STP and LTF similar to that in cats; the vermis may play a role in LTF. A new response, STD, was observed.

Sign in / Sign up

Export Citation Format

Share Document