CENTRAL STIMULATION OF RESPIRATION DURING HYPOXIA

1942 ◽  
Vol 136 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Carl A. Moyer ◽  
Henry K. Beecher
Keyword(s):  
Central Stimulation ◽  
Stimulation Of

Central Stimulation of Renin Secretion through Serotonergic, Noncardiovascular Mechanisms

1994 ◽  
Vol 60 (2) ◽  
pp. 205-214 ◽  
Author(s):  
Peter A. Rittenhouse ◽  
Erica A. Bakkum ◽  
Andrew D. Levy ◽  
Qian Li ◽  
Joseph M. Yracheta ◽  
...  
Keyword(s):  
Renin Secretion ◽  
Central Stimulation ◽  
Stimulation Of

scholarly journals Trigeminocardiac reflex during surgery in the cerebellopontine angle

1998 ◽  
Vol 5 (3) ◽  
pp. E9 ◽  
Author(s):  
Bernhard Schall ◽  
Rudolf Probst ◽  
Stephan Strebel ◽  
Peter Fuhr ◽  
Otmar Gratzl
Keyword(s):  
Blood Pressure ◽  
Trigeminal Nerve ◽  
Cerebellopontine Angle ◽  
Experimental Studies ◽  
Ocular Surgery ◽  
Trigeminocardiac Reflex ◽  
Arterial Blood ◽  
Nerve System ◽  
Central Stimulation ◽  
Stimulation Of

In different experimental studies authors have analyzed the autonomic responses elicited by the electrical, mechanical, or chemical stimulation of the trigeminal nerve system. The trigeminocardiac reflex (TCR) is a well-recognized phenomenon that consists of bradycardia, arterial hypotension, apnea, and gastric hypermotility. It occurs during ocular surgery and during other manipulations in and around the orbit. Thus far, it has not been shown that central stimulation of the trigeminal nerve can also cause this reflex. The TCR was defined as clinical hypotension with a drop in mean arterial blood pressure (MABP) of more than 20% and bradycardia lower than 60 beats/minute. Pre-, intra-, and postoperative heart rate (HR) and blood pressure were reviewed retrospectively in 125 patients who underwent surgery for tumors of the cerebellopontine angle (CPA), and they were divided into a TCR group and a non-TCR group. Of the 125 patients, 14 (11%) showed evidence of TCR during dissection of the tumor near the trigeminal nerve at the brainstem. Their HR fell 38% and their MABP fell 48% during operative procedures as compared with preoperative levels. After cessation of manipulation, the HR and the MABP returned to preoperative levels. Risk factors for the occurrence of TCR were compared with results from the literature. The authors' results show the possibility of occurrence of a TCR during manipulation of the central part of the trigeminal nerve when performing surgery in the CPA.

Rabbit cardiovascular responses to aortic nerve stimulation at fixed carotid pressure

1979 ◽  
Vol 236 (5) ◽  
pp. H769-H774
Author(s):  
H. O. Stinnett ◽  
D. F. Peterson ◽  
V. S. Bishop
Keyword(s):  
Heart Rate ◽  
Carotid Sinus ◽  
Cardiovascular Responses ◽  
Equilibrium Pressure ◽  
Aortic Nerve ◽  
Before And After ◽  
State Changes ◽  
Pressure Changes ◽  
Central Stimulation ◽  
Stimulation Of

In pentobarbital-anesthetized rabbits with aortic nerves cut, reflex heart rate and mean arterial pressure (MAP) changes were quantified in response to maximal central stimulation of the left aortic nerve (LANS) before and during steady-state changes in isolated carotid intrasinus pressure (ISP). To distinguish possible vagally mediated cardiopulmonary influences, responses were measured before and after vagotomy. Changes in MAP observed by altering ISP within +/- 15 mmHg of the equilibrium pressure (EP) were linear and inversely correlated to changes in ISP, with a slope of approximately 3 both before and after vagotomy (r greater than or equal to 0.929, P less than 0.05). The peak fall in MAP during LANS was dependent upon ISP. The change in the MAP responses to LANS for each mmHg change in ISP ranged from 1.7 with vagi intact to 1.3 after vagotomy. Heart rate was unaltered by isolation of the carotid sinus and was independent of the small changes in ISP between +/- 15 mmHg of EP. These results indicate that blood pressure changes elicited by the aortic baroreflex are extremely sensitive to the degree of carotid sinus compensation. Thus, to assess the sensitivity of any arterial reflex area, the existing level of compensation by other barosensitive areas must be known.

Motivational and Perceptual Aspects of Subcortical Stimulation in Cats

1958 ◽  
Vol 194 (2) ◽  
pp. 427-432 ◽  
Author(s):  
Harold C. Nielson ◽  
Robert W. Doty ◽  
Lester T. Rutledge
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Minute Period ◽  
The Press ◽  
The Central Nervous System ◽  
Subcortical Stimulation ◽  
To Receive ◽  
Central Stimulation ◽  
Stimulation Of

Reports of others that animals will seek electrical stimulation of certain regions of the central nervous system are confirmed. A method is presented whereby these ‘motivational’ aspects of central stimulation can be analyzed and shown to be capable of change by training and to have a different threshold from the animal's ‘perception’ of this stimulation. Cats were trained to press a bar to receive pellets of meat. When each bar-press was accompanied by stimulation through electrodes implanted in the caudate nucleus or anterior hypothalamus, the animals continued pressing. If the press was paired with stimulation of the septal or habenular regions, pressing was abolished. Foot-shock paired with pressing also produced avoidance but pairing with a startling buzzer did not. Caudatal stimulation of 0.2 ma, 50/sec., 2-msec. pulses, was adequate as conditional stimulus to establish conditioned foreleg flexions to avoid an electric shock. Subsequent to the latter training two animals would no longer press the bar if pressing resulted in caudatal stimulation. Other cats would press as often as 1000 times in a 20-minute period to obtain caudatal stimulation if it were allowed at rapid rates and intensities five times that required to evoke conditioned flexion reflexes. The evidence suggests that avidity develops for stimulation of certain neural structures only if the stimulus is adequate to initiate some form of excessive, seizure-like activity.

BLOOD FLOW CHANGES IN THE PITUITARY NEURAL LOBE OF THE RABBIT ASSOCIATED WITH NEUROHYPOPHYSIAL HORMONE-RELEASING STIMULI

1973 ◽  
Vol 57 (1) ◽  
pp. 75-85 ◽  
Author(s):  
T. SOORIYAMOORTHY ◽  
A. LIVINGSTON
Keyword(s):  
Blood Flow ◽  
Vagal Stimulation ◽  
Significant Rise ◽  
Posterior Pituitary ◽  
Neural Lobe ◽  
Sympathomimetic Drugs ◽  
Pituitary Glands ◽  
Flow Changes ◽  
Central Stimulation ◽  
Stimulation Of

SUMMARY Blood flow rates in the posterior pituitary glands of rabbits were calculated by measuring the clearance of locally deposited 133Xe in saline detected by an externally located probe. These studies indicated that intraarterial injection of CaCl2 and central stimulation of a vagus (both hormone-releasing stimuli) caused a significant rise in blood flow, whilst during haemorrhage, also a release stimulus, the blood flow in the posterior pituitary was maintained. Pretreatment with atropine abolished the increase seen with CaCl2 and vagal stimulation and caused a significant fall in blood flow after haemorrhage. Parasympathomimetic drugs caused an increase in the flow which was also atropine-sensitive; sympathomimetic drugs and sympathetic blocking drugs caused no alteration in blood flow. These results indicate that there is a local increase in blood flow in the posterior pituitary which is associated with hormone-releasing stimuli and which is cholinergically mediated.

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