The Functional Morphology of the Hypothalamo-Hypophyseal Neurosecretory System (HHNS) After Direct and Reflex Stimulation of the Hypothalamus in Cats

1978 ◽  
pp. 132-132
Author(s):  
E. A Borisova ◽  
S. I. Teplov
Keyword(s):  
Functional Morphology ◽  
Neurosecretory System ◽  
Reflex Stimulation ◽  
Stimulation Of

THE EFFECT OF GONADECTOMY ON THE RESPONSE OF THE PITUITARY I. C. S. H.-CONTENT TO STEROID SEX HORMONES

1960 ◽  
Vol XXXV (II) ◽  
pp. 245-252 ◽  
Author(s):  
G. P. van Rees ◽  
F. J. A. Paesi
Keyword(s):  
Sex Hormones ◽  
Sex Steroids ◽  
Low Dose ◽  
Testosterone Propionate ◽  
Preceding Paper ◽  
Direct Consequence ◽  
Two Factors ◽  
Reflex Stimulation ◽  
Steroid Sex Hormones ◽  
Stimulation Of

ABSTRACT In the experiments reported in this paper the hypothesis that the decrease in the pituitary I. C. S. H.-content, which occurs after administration of steroid sex hormones in gonadectomized animals, is counteracted by a reflex stimulation of the hypophysis initiated by the operation has been investigated. If treatment with a low dose of testosterone propionate (100 μg) was started immediately after castration, the resulting decrease in the pituitary I. C. S. H.-content became more marked if the reflex stimulation of the hypophysis had been prevented. If, however, two months were allowed to elapse before the beginning of treatment, the presence or absence of this reflex was no longer of importance for the effect of testosterone propionate on the pituitary I. C. S. H.-content. And yet, in this case too, the decrease in the pituitary I. C. S. H.-content by testosterone propionate was less than in intact animals (see preceding paper). Hence this decrease appears to be counteracted by two factors: one rapidly occurring and short lasting, resulting from a reflex elicited by gonadectomy; the other gradually increasing in potency and possibly a direct consequence of the continued absence of pituitary inhibiting sex steroids.

Synaptic Responses of Neurons Controlling the Parotid and von Ebner Salivary Glands in Rats to Stimulation of the Solitary Nucleus and Tract

2008 ◽  
Vol 99 (3) ◽  
pp. 1267-1273 ◽  
Author(s):  
Takeshi Suwabe ◽  
Hideyuki Fukami ◽  
Robert M. Bradley
Keyword(s):  
Salivary Glands ◽  
Sensory Information ◽  
Salivary Secretion ◽  
Afferent Input ◽  
Membrane Hyperpolarization ◽  
Neuron Response ◽  
Glutamate Receptor Antagonists ◽  
Autonomic Neurons ◽  
Reflex Stimulation ◽  
Stimulation Of

Salivary secretion results from reflex stimulation of autonomic neurons via afferent sensory information relayed to neurons in the rostral nucleus of the solitary tract (rNST), which synapse with autonomic neurons of the salivatory nuclei. We investigated the synaptic properties of the afferent sensory connection to neurons in the inferior salivatory nucleus (ISN) controlling the parotid and von Ebner salivary glands. Mean synaptic latency recorded from parotid gland neurons was significantly shorter than von Ebner gland neurons. Superfusion of GABA and glycine resulted in a concentration-dependent membrane hyperpolarization. Use of glutamate receptor antagonists indicated that both AMPA and N-methyl-d-aspartate (NMDA) receptors are involved in the evoked excitatory postsynaptic potentials (EPSPs). Inhibitory postsynaptic potential (IPSP) amplitude increased with higher intensity ST stimulation. Addition of the glycine antagonist strychnine did not affect the amplitude of the IPSPs significantly. The GABAA receptor antagonist, bicuculline (BMI) or mixture of strychnine and BMI abolished the IPSPs in all neurons. IPSP latency was longer than EPSP latency, suggesting that more than one synapse is involved in the inhibitory pathway. Results show that ISN neurons receive both excitatory and inhibitory afferent input mediated by glutamate and GABA respectively. The ISN neuron response to glycine probably derives from descending connections. Difference in the synaptic characteristics of ISN neurons controlling the parotid and von Ebner glands may relate to the different function of these two glands.

scholarly journals Stimulus-secretion coupling in the neurohypophysis of the jerboa Jaculus orientalis.

1994 ◽  
Vol 195 (1) ◽  
pp. 19-34
Author(s):  
A Raji ◽  
J J Nordmann
Keyword(s):  
Time Course ◽  
Physiological State ◽  
Nerve Endings ◽  
Neurosecretory System ◽  
Channel Blockers ◽  
Vasopressin Release ◽  
Oxytocin Release ◽  
Stimulus Secretion Coupling ◽  
Stimulation Of

1. In many mammals, severe dehydration is known to cause exhaustion of the vasopressin content of the neural lobe. Here, we have examined the physiological state of the neurohypophysis of the jerboa Jaculus orientalis, a rodent inhabitant of a semi-desert climate. 2. Isolated neurohypophyses and neurosecretory nerve endings were perfused in vitro and vasopressin and oxytocin release were determined by radioimmunoassay. 3. Electrical stimulation of the neurohypophysis with bursts of pulses mimicking the activity of hypersecreting neuroendocrine neurones induced similar increases of secretion in both control animals and animals dehydrated for up to 2 months. Neurohormone release was greatly potentiated when the bursts of pulses were separated by silent intervals. 4. Prolonged stimulation of neurohypophyses from both control and dehydrated animals induced a sustained increase of vasopressin release; in contrast, oxytocin release under similar conditions showed a biphasic secretory pattern consisting of a transient increase that subsequently decreased to a steady level whose amplitude was similar to that for vasopressin. 5. K(+)-induced secretion was largely inhibited by the Ca2+ channel blockers nicardipine and omega-conotoxin, suggesting that in this neurosecretory system both L- and N-type calcium channels play a major role in stimulus-secretion coupling. Depolarization of isolated nerve endings using a fast-flow perifusion system showed that there was no difference in the amplitude and the time course of the secretory response in dehydrated and hydrated animals. 6. The results demonstrate that, despite the climatic conditions in which the jerboas live, their neural lobes retain the capacity to release, upon depolarization of the plasma membrane of the nerve endings, large amounts of neurohormone. It is concluded that the neurohypophyseal peptidergic release system in the dehydrated jerboa functions adequately even under extreme environmental stress.

Effect of baroreceptor reflex stimulation on blood flow to an atelectatic lung

1982 ◽  
Vol 52 (5) ◽  
pp. 1128-1132 ◽  
Author(s):  
W. B. Strawn ◽  
S. M. Hall ◽  
M. G. Levitzky
Keyword(s):  
Blood Flow ◽  
Carotid Sinus ◽  
Initial Period ◽  
Pulmonary Arteries ◽  
Baroreceptor Reflex ◽  
Physiological Salt Solution ◽  
Vascular Response ◽  
Left And Right ◽  
Reflex Stimulation ◽  
Stimulation Of

The effect of baroreceptor reflex stimulation by carotid sinus hypotension on the pulmonary vascular response to atelectasis was studied in eight dogs anesthetized with chloralose. Closed-chest dogs with electromagnetic flow probes previously implanted on their left (QL) and main (QT) pulmonary arteries had their left and right lungs ventilated separately. Their carotid sinuses were isolated bilaterally and perfused by a pulsatile pump with a physiological salt solution. After an initial period of bilateral 100% O2 ventilation with carotid sinus perfusion pressures (CSPP) set at each animal's initial mean arterial pressure (98 +/- 19 Torr), the left airway was occluded, QL/QT fell from 0.33 +/- 0.01 to 0.24 +/- 0.02 and PO2 fell from 323 +/- 35 Torr to 74 + 7 Torr. When CSPP was lowered to 21 +/- 3 Torr, there were no changes in QL/QT and PO2. These results suggest that stimulation of the baroreceptor reflex by carotid sinus hypotension does not interfere with the diversion of pulmonary blood flow away from a unilaterally atelectatic lung.

REFLEX STIMULATION OF RESPIRATION FROM INCREASE IN VENOUS PRESSURE

1932 ◽  
Vol 100 (2) ◽  
pp. 417-419 ◽  
Author(s):  
T. R. Harrison ◽  
W. G. Harrison ◽  
J. P. Marsh
Keyword(s):  
Venous Pressure ◽  
Reflex Stimulation ◽  
Stimulation Of

scholarly journals Role of indole derivative SS-68 in increasing the frequency range of cardiac rhythm control (reflex stimulation of the sinoatrial node)

2021 ◽  
Vol 7 (3) ◽  
pp. 73-81
Author(s):  
Pavel A. Galenko-Yaroshevsky ◽  
Anatoly A. Nechepurenko ◽  
Tatiana G. Pokrovskaya ◽  
Nikolai L. Shimonovsky ◽  
Alexander S. Dukhanin ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Medulla Oblongata ◽  
High Frequency ◽  
Sinoatrial Node ◽  
Heart Rhythm ◽  
Cardiac Pacing ◽  
High Frequency Electromagnetic Field ◽  
Reflex Stimulation ◽  
Reflexogenic Zone ◽  
Stimulation Of

Introduction: Cardiac pacing is indicated for sick sinus syndrome. It is performed with a pacemaker via electrodes implanted in the heart. This technique has several disadvantages. The search for alternative methods of cardiac pacing is underway. One of them is control of heart rhythm through stimulation of the tragus. Objective: To perform the reflex stimulation of the sinoatrial node and to study the influence of the SS-68 substance on it. Materials and methods: Two electrodes were fixed in the reflexogenic zone of rabbits’ auricles, volleys of electrical impulses from an electrical stimulator were applied to the electrodes, and the synchronization range of volley frequency and cardiac contractions was recorded. This range was re-recorded again after injecting the SS-68 substance (2-phenyl-1-(3-pyrrolidine-1-cyclopropyl)-1H-indole hydrochloride) intravenously at a dose of 50 µg/kg. In other experiments on frogs in a high-frequency electromagnetic field, the process of excitation of the area of the medulla oblongata associated with the heart rhythm was visualized. After the application of SS-68 (50 μM) to the surface of this zone, the process of its excitation was recorded. Results and discussion: Stimulation of the auricular reflexogenic zone of rabbits produced a synchronization of volley frequency and heart rate in the range from 173.5 ± 2.0 to 214.0 ± 1.8 per minute. SS-68 extended this range from 168.2 ± 1.9 to 219.4 ± 1.5 per minute. In the frog’s medulla oblongata, an area synchronous to the heart rhythm glowed in the high-frequency electromagnetic field. SS-68 increased the area of glow by 131.0%. Conclusion: The substance SS-68 increases the frequency range of heart rhythm control by activating reflex stimulation of the sinoatrial node. The main point of application of SS-68 is the medulla oblongata. Glow in the high-frequency electromagnetic field reflects the process of neuron excitation. The increase in the glow zone under the influence of SS-68 indicates synchronously excited neurons, which leads to the assimilation of the central heart rhythm generation by the sinoatrial node.

Reflex control of the tracheal vasculature of sheep

1993 ◽  
Vol 75 (5) ◽  
pp. 2173-2179 ◽  
Author(s):  
S. E. Webber ◽  
J. G. Widdicombe
Keyword(s):  
Carotid Body ◽  
Muscle Tone ◽  
Intravenous Injections ◽  
Stretch Receptors ◽  
Pulmonary Stretch Receptors ◽  
Before And After ◽  
Cervical Trachea ◽  
Carotid Body Chemoreceptors ◽  
Reflex Stimulation ◽  
Stimulation Of

Arteries to the cervical trachea were perfused at constant flow in anesthetized sheep. Perfusion pressures (PP), blood pressure (BP), and changes in tracheal smooth muscle tone (Ptr) were measured. Stimulation of pulmonary C-fiber receptors decreased PP (-6.5%) and BP (-16.8%) and increased Ptr (+61.5%), changes prevented by vagotomy and therefore reflex. Stimulation of cardiac receptors and slowly adapting pulmonary stretch receptors decreased PP (-7.9%) and BP (-21.0) and increased Ptr (+19.0%), changes reversed by vagotomy and therefore reflex. Stimulation and inhibition of slowly adapting pulmonary stretch receptors had no vagal-dependent effect on PP and BP, but inflation decreased (-20.3%) and deflation increased Ptr (+35.2%), effects abolished by vagotomy and therefore reflex. Systemic hypoxia increased PP and BP before and after vagotomy (+12.2 and +40.3%), effects greatly reduced by cutting the carotid body nerves; it increased Ptr (+29.8%), an effect abolished by vagotomy and cutting the carotid body nerves. Systemic hypercapnia increased PP (+16.9%), BP (+20.5%), and Ptr (+36.2%), the first two responses being unaffected by vagotomy and the last almost abolished. Stimulation of carotid body chemoreceptors by KCN increased PP (+22.5%), BP (+104.7%), and Ptr (+8.5%), all responses prevented by cutting the carotid body nerves. Responses to intravenous injections of KCN were similar.

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