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

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.

2001 ◽  
Vol 91 (4) ◽  
pp. 1713-1722 ◽  
Author(s):  
Fadi Xu ◽  
Tongrong Zhou ◽  
Tonya Gibson ◽  
Donald T. Frazier

Electrical stimulation of the rostral fastigial nucleus (FNr) alters respiration via activation of local neurons. We hypothesized that this FNr-mediated respiratory response was dependent on the integrity of the nucleus gigantocellularis of the medulla (NGC). Electrical stimulation of the FNr in 15 anesthetized and tracheotomized spontaneously breathing rats significantly altered ventilation by 35.2 ± 11.0% ( P < 0.01) with the major effect being excitatory (78%). This respiratory response did not significantly differ from control after lesions of the NGC via bilateral microinjection of kainic or ibotenic acid (4.5 ± 1.9%; P > 0.05) but persisted in sham controls. Eight other rats, in which horseradish peroxidase (HRP) solution was previously microinjected into the left NGC, served as nonstimulation controls or were exposed to either 15-min repeated electrical stimulation of the right FNr or hypercapnia for 90 min. Histochemical and immunocytochemical data showed that the right FNr contained clustered HRP-labeled neurons, most of which were double labeled with c-Fos immunoreactivity in both electrically and CO2-stimulated rats. We conclude that the NGC receives monosynaptic FNr inputs and is required for fully expressing FNr-mediated respiratory responses.


2020 ◽  
Author(s):  
Reiko Ashida ◽  
Peter Walsh ◽  
Jonathan C.W. Brooks ◽  
Richard J. Edwards ◽  
Nadia L. Cerminara ◽  
...  

AbstractDamage to the cerebellum during posterior fossa surgery can lead to ataxia and in paediatric cases, the risk of cerebellar mutism syndrome. Animal electrophysiological and human imaging studies have shown compartmentalisation of sensorimotor and cognitive functions within the cerebellum. In the present study, electrophysiological monitoring of sensory and motor pathways was carried out to assess the location of limb sensorimotor representation within the human cerebellum, as a potential approach for real time assessment of neurophysiological integrity to reduce the incidence of cerebellar surgical morbidities.Thirteen adult and paediatric patients undergoing posterior fossa surgery were recruited. For sensory mapping (n=8), electrical stimulation was applied to the median nerves, the posterior tibial nerves, or proximal and distal limb muscles and evoked field potential responses were sought on the cerebellar surface. For motor mapping (n=5), electrical stimulation was applied to the surface of the cerebellum and evoked EMG responses were sought in facial and limb muscles.Evoked potentials on the cerebellar surface were found in two patients (25% of cases). In one patient, the evoked response was located on the surface of the right inferior posterior cerebellum in response to stimulation of the right leg. In the second patient, stimulation of the extensor digitorum muscle in the left forearm evoked a response on the surface of the left inferior posterior lobe. In the motor mapping cases no evoked EMG responses could be found.Intraoperative electrophysiological mapping, therefore, indicates it is possible to record evoked potentials on the surface of the human cerebellum in response to peripheral stimulation.


1983 ◽  
Vol 54 (1) ◽  
pp. 215-224 ◽  
Author(s):  
S. G. Hendrix ◽  
N. M. Munoz ◽  
A. R. Leff

We studied the isometric response of bronchial smooth muscle in a single third-order bronchus of 24 dogs in situ. Length-tension studies were performed in six dogs by repeated injection of 10(-5) mol acetylcholine (ACh) into the right bronchoesophageal artery, and the resting tension (30.6 +/- 6.9 g/cm) and length (0.76 +/- 0.14 cm) permitting maximal contraction were determined. In eight other dogs, dose-related bronchial contraction was obtained with 10(-10) to 10(-5) mol intra-arterial (ia) ACh. Supramaximal electrical stimulation of the right cervical vagus nerve and bronchial parasympathetic ganglion stimulation with ia 1–1-dimethyl-4-phenylpiperazinium (DMPP) also caused bronchial contraction. The maximal response to ia ACh (28.5 +/- 1.7 g/cm), supramaximal electrical stimulation (15.2 +/- 1.1 g/cm), and ia DMPP (10.5 +/- 3.0 g/cm) was blocked by an ia dose of atropine (1–5 micrograms/kg) that did not alter the sympathetic relaxation response in the trachea. In four dogs, the bronchial response to sympathetic activation was studied by intravenous (iv) bolus injection of DMPP after cholinergic blockade with atropine. DMPP (25 micrograms/kg iv) caused 9.5 +/- 2.2 g/cm bronchial relaxation, which was blocked completely by 2–4 mg/kg iv propranolol. In six other dogs, hypoxia induced by ventilation with pure nitrogen caused bronchial contraction, which was blocked by vagotomy, atropine, and hexamethonium. We report a sensitive method for selective measurement of bronchial smooth muscle response in a single resistance bronchus. This preparation preserves regional innervation and circulation and permits selective physiological stimulation in situ.


2002 ◽  
Vol 282 (4) ◽  
pp. H1278-H1287 ◽  
Author(s):  
Pedro Boscan ◽  
Julian F. R. Paton

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.


1988 ◽  
Vol 66 (3) ◽  
pp. 380-384 ◽  
Author(s):  
Sylvain Foucart ◽  
Jacques de Champlain ◽  
Reginald Nadeau

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.


2002 ◽  
Vol 87 (4) ◽  
pp. 2195-2199 ◽  
Author(s):  
David L. Zealear ◽  
Ricardo J. Rodriguez ◽  
Thomas Kenny ◽  
Mark J. Billante ◽  
Young Cho ◽  
...  

The effect of electrical stimulation of the denervated posterior cricoarytenoid (PCA) muscle on its subsequent reinnervation was explored in the canine. Eight animals were implanted with a planar array of 36 electrodes for chronic stimulation and recording of spontaneous and evoked electromyographic (EMG) potentials across the entire fan-shaped surface of a muscle pair. Normative EMG data were recorded from each electrode site before unilateral nerve section, and from the innervated partner after nerve section. After randomizing the animals to experimental and control groups, the right recurrent laryngeal nerve innervating the PCA abductor muscle and its adductor antagonists was sectioned and reanastomosed. The PCA muscle in four experimental animals was continuously stimulated during the 11-mo experiment, using a 1-s, 30-pps, biphasic pulse train composed of 1-ms pulses 2–6 mA in amplitude and repeated every 10 s. The remaining four animals served as nonstimulated controls. Appropriate reinnervation by native inspiratory motoneurons was indexed behaviorally by the magnitude of vocal fold opening and electromyographically by the potential across all electrode sites. Inappropriate reinnervation by foreign adductor motoneurons was quantitated by recording EMG potentials evoked reflexly by stimulation of sensory afferents of the laryngeal mucosa. All four experimental animals showed a greater level of correct PCA muscle reinnervation ( P < 0.0064) and a lesser level of incorrect reinnervation ( P < 0.0084) than the controls. Direct muscle stimulation also appeared to enhance the overall magnitude of reinnervation, but the effect was not as strong ( P < 0.113). These findings are consistent with a previous report and suggest that stimulation of a mammalian muscle may profoundly affect its receptivity to reinnervation by a particular motoneuron type.


2009 ◽  
Vol 61 (5) ◽  
pp. 1073-1082 ◽  
Author(s):  
Yiqun Xue ◽  
Xiying Chen ◽  
Thomas Grabowski ◽  
Jinhu Xiong

2000 ◽  
Vol 93 (5) ◽  
pp. 774-783 ◽  
Author(s):  
Maxwell Boakye ◽  
Sean C. Huckins ◽  
Nikolaus M. Szeverenyi ◽  
Bobby I. Taskey ◽  
Charles J. Hodge

Object. Functional magnetic resonance (fMR) imaging was used to determine patterns of cerebral blood flow changes in the somatosensory cortex that result from median nerve stimulation (MNS).Methods. Ten healthy volunteers underwent stimulation of the right median nerve at frequencies of 5.1 Hz (five volunteers) and 50 Hz (five volunteers). The left median nerve was stimulated at frequencies of 5.1 Hz (two volunteers) and 50 Hz (five volunteers). Tactile stimulation (with a soft brush) of the right index finger was also applied (three volunteers). Functional MR imaging data were transformed into Talairach space coordinates and averaged by group. Results showed significant activation (p < 0.001) in the following regions: primary sensorimotor cortex (SMI), secondary somatosensory cortex (SII), parietal operculum, insula, frontal cortex, supplementary motor area, and posterior parietal cortices (Brodmann's Areas 7 and 40). Further analysis revealed no statistically significant difference (p > 0.05) between volumes of cortical activation in the SMI or SII resulting from electrical stimuli at 5.1 Hz and 50 Hz. There existed no significant differences (p > 0.05) in cortical activity in either the SMI or SII resulting from either left- or right-sided MNS. With the exception of the frontal cortex, areas of cortical activity in response to tactile stimulation were anatomically identical to those regions activated by electrical stimulation. In the SMI and SII, activation resulting from tactile stimulation was not significantly different (p > 0.05) from that resulting from electrical stimulation.Conclusions. Electrical stimulation of the median nerve is a reproducible and effective means of activating multiple somatosensory cortical areas, and fMR imaging can be used to investigate the complex network that exists between these areas.


2018 ◽  
Vol 16 (2) ◽  
pp. 37-41
Author(s):  
Nikolay S Efimov ◽  
Yulia N Bessolova ◽  
Inessa V Karpova ◽  
Andrei A Lebedev ◽  
Petr D Shabanov

In the protocols of modern pharmacological studies of a self-stimulation reaction in rodents, stimulating electrodes are implanted as a rule unilaterally. The reinforcing properties of the left and right hypothalamus were suggested to be identical. The aim of the study was to clear up if the possibilities of the left and right hypothalamus to produce self-stimulation are similar or not. Methods. The study was carried out on adult male Wistar rats. The electrodes were implanted into the lateral hypothalamus bilaterally. The rats, in which an approach reaction was observed, learned self-stimulation in the Skinner box with stimulation of the left or right hypothalamus as a reinforcing agent descending thresholds of stimulation up to minimal one. Results. Self-stimulation of the left hypothalamus gave an approach reaction in the majority of rats (81.8%), self-stimulation reaction was developed in 72.7% of rats. Only 46.2% rats reacted on stimulation of the right hypothalamus, self-stimulation reaction was developed in 30.8% of rats. The thresholds of positive and negative reactions registered after electrical stimulation of both sides of hypothalamus were significantly differed (H(3, N = 31) = 14,92; p = 0,002). And these changes were not connected with lateralization but with sign of reaction: in general the thresholds of approach reaction were higher than thresholds of avoidance. Conclusion. In the paper, the fact of different possibility of approach reaction and self-stimulation development as a result of electrical stimulation of the left and right hypothalamus in rats has been described. After stimulation of the left hypothalamus, a possibility to receive positive reaction and to form self-stimulation on its basis is higher than after stimulation of the right hypothalamus. (For citation: Efimov NS, Bessolova YN, Karpova IV, et al. Asymmetry of reinforcing properties of the lateral hypothalamus in the self-stimulation test. Reviews on Clinical Pharmacology and Drug Therapy. 2018;16(2):37-41. doi: 10.17816/RCF16237-41).


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