In situ demonstration of changes in the preoptico-neurohypophysical complex after electrical stimulation of the olfactory tract in the catfish Clarias batrachus (Linn.)

1973 ◽  
Vol 139 (1) ◽  
pp. 95-99 ◽  
Author(s):  
P. D. Prasada Rao ◽  
K. B. Dabhade
Keyword(s):  
Electrical Stimulation ◽  
Clarias Batrachus ◽  
Olfactory Tract ◽  
Stimulation Of

Integration of cornea and cardiorespiratory afferents in the nucleus of the solitary tract of the rat

2002 ◽  
Vol 282 (4) ◽  
pp. H1278-H1287 ◽  
Author(s):  
Pedro Boscan ◽  
Julian F. R. Paton
Keyword(s):  
Electrical Stimulation ◽  
Solitary Tract ◽  
Peripheral Chemoreceptor ◽  
Single Unit Recordings ◽  
Degree Of Convergence ◽  
High Degree ◽  
Working Heart ◽  
Stimulation Of ◽  
Nerve Discharge

We determined the activity of neurons within the nucleus of the solitary tract (NTS) after stimulation of the cornea and assessed whether this input affected the processing of baroreceptor and peripheral chemoreceptor inputs. In an in situ, unanesthetized decerebrate working heart-brain stem preparation of the rat, noxious mechanical or electrical stimulation was applied to the cornea, and extracellular single unit recordings were made from NTS neurons. Cornea nociceptor stimulation evoked bradycardia and an increase in the cycle length of the phrenic nerve discharge. Of 90 NTS neurons with ongoing activity, corneal stimulation excited 51 and depressed 39. There was a high degree of convergence to these NTS neurons from either baroreceptors or chemoreceptors. The excitatory synaptic response in 12 of 19 baroreceptive and 10 of 15 chemoreceptive neurons was attenuated significantly during concomitant electrical stimulation of the cornea. This inhibition was GABAA receptor mediated, being blocked by pressure ejection of bicuculline. Thus the NTS integrates information from corneal receptors, some of which converges onto neurons mediating reflexes from baroreceptors and chemoreceptors to inhibit these inputs.

In vivo modulation by α2-adrenoceptors of adrenal catecholamine release in the anaesthetized dog

1988 ◽  
Vol 66 (3) ◽  
pp. 380-384 ◽  
Author(s):  
Sylvain Foucart ◽  
Jacques de Champlain ◽  
Reginald Nadeau
Keyword(s):  
Electrical Stimulation ◽  
Splanchnic Nerve ◽  
Catecholamine Release ◽  
Agonist Stimulation ◽  
Control Stimulation ◽  
Anaesthetized Dog ◽  
Splanchnic Nerve Stimulation ◽  
Stimulation Of

In this study, the reversal of the potentiating effect of idazoxan, a selective α2-antagonist, on adrenal catecholamine release elicited by splanchnic nerve stimulation in anaesthetized and vagotomized dogs, was investigated with the use of oxymetazoline, a selective α2-agonist. Stimulation of the left splanchnic nerve (5.0-V pulses of 2 ms duration for 3 min at a frequency of 2 Hz) was applied before and 20 min after the i. v. injection of each drug. Blood samples were collected in the adrenal vein before and at the end of each stimulation. The results show that the release of catecholamines induced by electrical stimulation was potentiated by 50% after idazoxan injection (0.1 mg/kg). This enhanced response was significantly antagonized by the subsequent injection of oxymetazoline (2 μg/kg). The α2-modulating effect appears to be related to the amount of catecholamines released during the stimulation, since by subgrouping of the data on the basis of the degree of potentiation by idazoxan, it was observed that this drug was more efficient when catecholamine release was higher during control stimulation. In contrast, the reversing effect of oxymetazoline was found to be more pronounced when catecholamine release was lower. These results thus suggest that the sensitivity of the α2-adrenoceptor mechanism may depend upon the in situ concentration of adrenal catecholamine release during electrical stimulation and that the potentiating effect of α2-blockade can be reversed by activation of those receptors by a selective α2-agonist.

An Electrophysiological Study of the Photo-Excitative Neurones of Onchidium Verruculatum in Situ

1972 ◽  
Vol 57 (3) ◽  
pp. 661-671
Author(s):  
NOZOMU HISANO ◽  
HIDEKI TATEDA ◽  
MASUTARO KUWABARA
Keyword(s):  
Electrical Stimulation ◽  
Electrophysiological Study ◽  
Spontaneous Discharge ◽  
Light Stimulation ◽  
Direct Response ◽  
Intracellular Stimulation ◽  
The Right ◽  
Animal Preparation ◽  
Stimulation Of

1. The distribution of the axons of the photo-excitative neurones in Onchidium verruculatum has been traced by intracellular stimulation of the soma and extracellular stimulation of the axon. They send axon branches mainly into the pleuroparietal and abdominal nerves in both sides. 2. In the whole-animal preparation, photo-excitative spikes could be recorded from neither the soma nor the nerves of inherently photo-excitative neurones during light stimulation. ‘On’ and ‘off’ spikes were initiated only immediately after the beginning and the cessation of illumination of a whole animal. 3. ‘Off’ spikes originated from dorsal eyes and stalk eyes to which shadow stimuli were applied. Those spikes were not the direct response of photo-excitative neurones to light. 4. The excitation of the inherently photo-excitative neurones in situ was suppressed by inhibitory inputs coming through the right and left pleuro-parietal nerves. Cutting one (or some) of the pleuro-parietal nerves was the only condition that diminished the inhibitory inputs to the photo-excitative neurones in the present work. Adequate electrical stimulation of the pleuro-parietal nerves inhibited spikes of photo-excitative neurones due to photo-excitator or spontaneous discharge.

Metabolic Response to Electrical Stimulation in Separated Portions of Human Cerebral Tissues

1952 ◽  
Vol 98 (411) ◽  
pp. 265-272 ◽  
Author(s):  
H. McIlwain ◽  
P. J. W. Ayres ◽  
Olga Forda
Keyword(s):  
Electrical Stimulation ◽  
Chemical Analysis ◽  
Metabolic Response ◽  
Venous Blood ◽  
Blood Stream ◽  
Small Areas ◽  
Flow Information ◽  
The Brain ◽  
Stimulation Of

Electrical stimulation of different areas of the human brain has hitherto been confined to experiments with the brain in situ, in living subjects. It has been carried out while the brain received its blood supply from normal sources. By chemical analysis of the arterial and venous blood and measurement of its rate of flow, information has been obtained on how metabolic changes in the brain vary with changes in its activity. However, these conditions can give information only about gross biochemical changes associated with stimulation; they are cumbersome, and would not indicate abnormal reactions in small areas. Also, they detect differences only in substances which are actively exchanged with the blood stream.

Augmentation of alpha-adrenergic contractions in the trachealis muscle of living dogs

1983 ◽  
Vol 54 (6) ◽  
pp. 1558-1566 ◽  
Author(s):  
J. K. Brown ◽  
R. Shields ◽  
C. Jones ◽  
W. M. Gold
Keyword(s):  
Electrical Stimulation ◽  
Sympathetic Nerves ◽  
Cholinergic Agonists ◽  
Short Acting ◽  
In Situ Preparation ◽  
Anesthetized Dogs ◽  
Long Acting ◽  
Trachealis Muscle ◽  
Stimulation Of

Discrepancies exist between reported effects of histamine on the alpha-adrenergic responsiveness of the canine trachealis muscle. Therefore, using an in situ preparation described recently (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 49: 84–94, 1980), we tested the effects of histamine and other agents on alpha-adrenergic responses in the trachealis muscle of 34 anesthetized dogs. Under basal conditions, maximum alpha-adrenergic responses were small [3 +/- 1 (SE) g/cm] compared with those induced by a supramaximal parasympathetic stimulus (45 +/- 3 g/cm). After exposure of the muscle to histamine, responsiveness increased markedly to alpha-adrenergic stimuli, which included tracheal arterial injections of norepinephrine and phenylephrine or electrical stimulation of sympathetic nerves. Augmented alpha-adrenergic responsiveness persisted for 20 min after the end of contractions induced by histamine. Serotonin and long-acting, but not short-acting, cholinergic agonists also potentiated alpha-adrenergic responsiveness. We concluded that exposure of the trachealis muscle in living dogs to a variety of constrictor stimuli potently augmented its alpha-adrenergic responsiveness.

Olfactory evoked potentials: experimental and clinical studies

1996 ◽  
Vol 85 (6) ◽  
pp. 1122-1126 ◽  
Author(s):  
Masanori Sato ◽  
Namio Kodama ◽  
Tatsuya Sasaki ◽  
Mamoru Ohta
Keyword(s):  
Electrical Stimulation ◽  
Evoked Potentials ◽  
Olfactory System ◽  
Olfactory Nerve ◽  
Olfactory Mucosa ◽  
Content Type ◽  
Negative Peak ◽  
Olfactory Tract ◽  
Fine Print ◽  
Stimulation Of

✓ Olfactory evoked potentials (OEPs), obtained by electrical stimulation of the olfactory mucosa, were recorded in dogs and humans to develop an objective method for evaluating olfactory functions. In dogs, OEPs were recorded from the olfactory tract and the scalp. The latency of the first negative peak was approximately 40 msec. A response was not obtained after stimulation of the nasal mucosa and disappeared after sectioning of the olfactory nerve. With increasing frequencies of repetitive stimulation, the amplitude was reduced, suggesting that the response was synaptically mediated. These results demonstrate that evoked potentials from the olfactory tract and the scalp following electrical stimulation of the olfactory mucosa originate specifically from the olfactory system. In humans, a stimulating electrode with a soft catheter was fixed on the olfactory mucosa. The OEPs from the olfactory tract, recorded with a negative peak of approximately 27 msec, had similar characteristics to OEPs found in dogs. The OEPs from the olfactory tract in humans also originate specifically from the olfactory system. The authors postulate that OEPs obtained by electrical stimulation of the olfactory mucosa may prove useful for intraoperative monitoring of olfactory functions.

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