Release of a Neurosecretory Hormone as Peptide by Electrical Stimulation of Crab Pericardial Organs

1970 ◽  
Vol 53 (3) ◽  
pp. 679-686
Author(s):  
A. BERLIND ◽  
I. M. COOKE
Keyword(s):  
Peptide Binding ◽  
Compound Action Potential ◽  
Neural Stimulation ◽  
Distilled Water ◽  
Small Peptides ◽  
Free Peptide ◽  
Compound Action ◽  
Stimulation Of ◽  
Pericardial Organ ◽  
Bathing Fluid

1. Saline which had bathed an isolated crab pericardial organ was chromatographed on a column of Sephadex G-25. The fractions were divided and assayed for cardioexcitor activity and for ninhydrin colour following hydrolysis. 2. Fluid from pericardial organs which had been stimulated electrically to give a maximum propagated compound action potential showed both cardio-excitor activity and ninhydrin colour. These were always in the same fractions, which corresponded to the volume for elution of small peptides. Fluid from unstimulated preparations gave negative assays. 3. The cardio-excitor activity of fluid from stimulated pericardial organs and of distilled-water homogenates of pericardial organs behaved identically in Sephadex G-25 chromatography. 4. No evidence could be obtained of the cardio-excitor peptide binding to a protein. 5. This work provides evidence that neural stimulation of crab pericardial organs results in release to the bathing fluid of cardio-excitor hormone as free peptide.

Physiological studies of small mediastinal ganglia in the cardiopulmonary nerves of dogs

1984 ◽  
Vol 62 (9) ◽  
pp. 1244-1248 ◽  
Author(s):  
J. A. Armour
Keyword(s):  
Action Potential ◽  
Neuronal Cell ◽  
Compound Action Potential ◽  
Transitional Region ◽  
High Frequencies ◽  
Neuronal Cell Bodies ◽  
Wave Forms ◽  
Local Injections ◽  
Compound Action ◽  
Stimulation Of

Stimulation of the cranial end of a decentralized canine cardiopulmonary nerve results in the generation of a compound action potential which can be recorded at the caudal end. A region has been identified which, on stimulation, produces a compound action potential with complex configuration which is different from simpler wave forms obtained by stimulating 1 mm or more in either the rostral or caudal direction. Histological examination reveals that clusters of neuronal cell bodies are localized to this region of the nerve, whereas none is found to either side. Characteristics of the different wave forms evoked by changing the site of stimulation and reversing the stimulation and recording electrodes provide evidence for the existence of both afferent and efferent synaptic pathways. The compound action potential evoked by the most rostral stimulations and presumed to contain synaptic components was not altered by intravenously administered cholinergic and adrenergic pharmacological blocking agents (hexamethonium, atropine, phentolamine, or propranolol). It was, however, depressed by local injections of chymotrypsin or manganese into the functionally identified transitional region. It is concluded that synapses, which can be activated at relatively high frequencies (1–10 Hz) and may be important for rapidly changing local neural regulation of the heart and lungs, appear to exist within the course of cardiopulmonary nerves.

Stimulation of groups III and IV phrenic afferents reflexly decreases total lung resistance in dogs

1986 ◽  
Vol 61 (4) ◽  
pp. 1346-1351 ◽  
Author(s):  
L. W. McCallister ◽  
K. W. McCoy ◽  
J. C. Connelly ◽  
M. P. Kaufman
Keyword(s):  
Phrenic Nerve ◽  
Compound Action Potential ◽  
Motor Threshold ◽  
Group Iii ◽  
Airway Caliber ◽  
Lung Resistance ◽  
Cholinergic Tone ◽  
Total Lung Resistance ◽  
Compound Action ◽  
Stimulation Of

Little is known about the reflex effect on airway caliber evoked by stimulation of phrenic afferents. Therefore, in chloralose-anesthetized, paralyzed dogs, we recorded airflow, airway pressure, arterial pressure, and heart rate while electrically stimulating a phrenic nerve. Total lung resistance was calculated breath by breath. The phrenic nerve was stimulated at 3, 5, 20, 70, 140, and 200 times motor threshold and the compound action potential was recorded. Stimulation of the phrenic nerve at three and five times threshold, which activated groups I, II, and a few group III fibers, had no effect on any of the variables measured. Stimulation at 20 times threshold, which activated many group III fibers and groups I and II fibers, reflexly decreased resistance. Stimulation at 70, 140, and 200 times threshold, which activated groups I-IV fibers, evoked progressively greater decreases in lung resistance. The reflex bronchodilation evoked by phrenic nerve stimulation was unaffected by propranolol or phentolamine but was abolished by atropine. We conclude that activation of groups III and IV phrenic nerve afferents reflexly decreased total lung resistance by withdrawing cholinergic tone to airway smooth muscle.

scholarly journals Platform for Closed Loop Neuromodulation Based on Dual Mode Biosignals

2017 ◽  
Author(s):  
Khalid B. Mirza ◽  
Nishanth Kulasekeram ◽  
Simon Cork ◽  
Stephen Bloom ◽  
Konstantin Nikolic ◽  
...  
Keyword(s):  
Closed Loop ◽  
Compound Action Potential ◽  
Open Loop ◽  
Neural Stimulation ◽  
Appetite Control ◽  
Chemical Signatures ◽  
Signal Mode ◽  
On Chip ◽  
Final System ◽  
Compound Action

AbstractClosed loop neuromodulation, where the stimulation is controlled autonomously based on physiological events, has been more effective than open loop techniques. In the few existing closed loop implementations which have a feedback, indirect non-neurophysiological biomarkers have been typically used (e.g. heart rate, stomach distension). Although these biomarkers enable automatic initiation of neural stimulation, they do not enable intelligent control of stimulation dosage. In this paper, we present a novel closed loop neuromodulation platform based on a dual signal mode that is detecting electrical and chemical signatures of neural activity. We demonstrated it on a case of vagus nerve stimulation (VNS). Vagal chemical (pH) signal is detected and used for initiatisng VNS and vagal compound action potential (CAP) signals are used to determine the stimulation dosage and pattern. Although we used the paradigm of appetite control and neurometabolic therapies, the platform developed here can be utilised for prototyping closed loop neuromodulation systems before adapting the final System-on-Chip (SoC) design.

scholarly journals Effect of Chronological Age on Pulse Rate Discrimination in Adult Cochlear-Implant Users

2021 ◽  
Vol 25 ◽  
pp. 233121652110073
Author(s):  
Kelly C. Johnson ◽  
Zilong Xie ◽  
Maureen J. Shader ◽  
Paul G. Mayo ◽  
Matthew J. Goupell
Keyword(s):  
Pulse Rate ◽  
Compound Action Potential ◽  
Action Potential Amplitude ◽  
Growth Functions ◽  
Evoked Compound Action Potential ◽  
Rate Discrimination ◽  
Amplitude Growth ◽  
Temporal Pulse ◽  
Compound Action Potential Amplitude ◽  
Compound Action

Cochlear-implant (CI) users rely heavily on temporal envelope cues to understand speech. Temporal processing abilities may decline with advancing age in adult CI users. This study investigated the effect of age on the ability to discriminate changes in pulse rate. Twenty CI users aged 23 to 80 years participated in a rate discrimination task. They attempted to discriminate a 35% rate increase from baseline rates of 100, 200, 300, 400, or 500 pulses per second. The stimuli were electrical pulse trains delivered to a single electrode via direct stimulation to an apical (Electrode 20), a middle (Electrode 12), or a basal location (Electrode 4). Electrically evoked compound action potential amplitude growth functions were recorded at each of those electrodes as an estimate of peripheral neural survival. Results showed that temporal pulse rate discrimination performance declined with advancing age at higher stimulation rates (e.g., 500 pulses per second) when compared with lower rates. The age-related changes in temporal pulse rate discrimination at higher stimulation rates persisted after statistical analysis to account for the estimated peripheral contributions from electrically evoked compound action potential amplitude growth functions. These results indicate the potential contributions of central factors to the limitations in temporal pulse rate discrimination ability associated with aging in CI users.

Tension response of mammalian muscle to intra-arterial acetylcholine

1960 ◽  
Vol 198 (3) ◽  
pp. 507-510 ◽  
Author(s):  
Peter T. Rowley ◽  
Jay B. Wells ◽  
Richard L. Irwin
Keyword(s):  
Dose Response ◽  
Contractile Response ◽  
Tibialis Anterior Muscle ◽  
Arterial Occlusion ◽  
Isometric Tension ◽  
Neural Stimulation ◽  
Dose Response Relationship ◽  
Mammalian Muscle ◽  
Tension Response ◽  
Stimulation Of

Using isometric tension recording of the tibialis anterior muscle of the cat, the response to intra-arterial acetylcholine injection was studied and compared to the response to electrical stimulation of the nerve. The amount of acetylcholine, the rate of injection and the volume of diluent injected are interrelated factors in the production of tension. Regardless of the amount and concentration of the acetylcholine injected, the contractile response of the muscle has a slower rate of rise and a longer duration than the response from single maximal impulse stimulation to the nerve and a maximal tension less than from a tetanic neural stimulation. The dose-response relationship between the injected acetylcholine and the resultant tension and its modification by curare are described. The steep portion of the dose-response curve was found to occur in most experiments between 0.5 and 6.0 µg. A method of supplying blood to the muscle is described which provides more reliable intermittent arterial occlusion during injection.

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