Influence of Cholecystokinin-8 on Compound Nerve Action Potentials from Ventral Gastric Vagus in Rats

Mirza, Khalid B.; Alenda, Andrea; Eftekhar, Amir; Grossman, Nir; Nikolić, Konstantin; Bloom, Stephen R.; Toumazou, C.

doi:10.1142/s0129065718500065

Cited by 8 publications

(8 citation statements)

References 37 publications

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“…In ischemia reperfusion-and ethanolinduced gastric ulceration models, rats administered leptin [10 μg/kg body weight (BW)] showed significantly attenuated gastric lesions (Brzozowski et al, 2001). Notably, the protection conferred by leptin is as effective as that by CCK-8, a potent gastric protector (Mirza et al, 2018). Consistently, in rats with either indomethacin-induced or stress-induced gastric ulcer, leptin treatment (10 μg/kg BW, 6 h) significantly decreased the gastric ulcer index and neutrophil infiltration (Motawi et al, 2008;Khalefa et al, 2010).…”

Section: Stomachmentioning

confidence: 65%

Role of Leptin in the Digestive System

Kim

2021

Front. Pharmacol.

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Leptin is a pluripotent peptide hormone produced mainly by adipocytes, as well as by other tissues such as the stomach. Leptin primarily acts on the central nervous system, particularly the hypothalamus, where this hormone regulates energy homeostasis and neuroendocrine function. Owing to this, disruption of leptin signaling has been linked with numerous pathological conditions. Recent studies have also highlighted the diverse roles of leptin in the digestive system including immune regulation, cell proliferation, tissue healing, and glucose metabolism. Of note, leptin acts differently under physiological and pathological conditions. Here, we review the current knowledge on the functions of leptin and its downstream signaling in the gastrointestinal tract and accessory digestive organs, with an emphasis on its physiological and pathological implications. We also discuss the current therapeutic uses of recombinant leptin, as well as its limitations.

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Section: Stomachmentioning

confidence: 65%

Role of Leptin in the Digestive System

Kim

2021

Front. Pharmacol.

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“…The present study has several limitations. First, previous studies have reported that the frequency of cervical VNS used in different I/R injuries ranges from 2 to 20 Hz (Cao et al, 2017; Stauss, 2017; Mirza et al, 2018). In the present study, we evaluated the effect of VNS at 5 Hz in the retinal I/R model.…”

Section: Discussionmentioning

confidence: 99%

Vagal Nerve Stimulation Attenuates Ischemia-Reperfusion Induced Retina Dysfunction in Acute Ocular Hypertension

et al. 2019

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Purpose: The present study aimed to investigate whether cervical vagal nerve stimulation (VNS) could prevent retinal ganglion cell (RGC) loss and retinal dysfunction after ischemia/reperfusion (I/R) injury.Methods: First, rats were randomly divided into sham group (n = 4) and VNS group (n = 12). Activation of the nodose ganglia (NOG), nucleus of the solitary tract (NTS), superior salivatory nucleus (SSN), and pterygopalatine ganglion (PPG) neural circuit were evaluated by c-fos expression at 0 h after sham VNS and at 0 h (n = 4), 6 h (n = 4), 72 h (n = 4) after VNS. Secondly, rats were randomly assigned to I/R group (pressure-induced retinal ischemia for 1 h and reperfusion for 1 h in the right eye, n = 16) and I/R+VNS group (right cervical VNS for 2 h during the I/R period, n = 16). The left eye of each rat served as a control. Electroretinogram (ERG), RGC numbers, tumor necrosis factor-α (TNF-α) and vasoactive intestinal polypeptide (VIP) levels in retina were determined. Additionally, the level of VIP in PPG was evaluated.Results: In the first part of the study, compared with the sham group, the VNS group exhibited significantly increased expression of c-fos in NOG, NTS, SSN, and PPG tissues at 0, 6, and 72 h. In the second part of the study, compared with left eyes, retinal function in right eyes (as assessed by the a-wave, b-wave and the oscillatory potential amplitudes of ERG and RGC data) was significantly decreased by I/R. The decreased retinal function was attenuated by VNS. In addition, I/R induced an increase in inflammation, which was reflected by elevated TNF-α expression in the retina. VNS significantly attenuated the increase in I/R-induced inflammation. Moreover, VIP expression in the retina and PPG, which may contribute to the inhibition of the inflammatory response, was significantly increased after VNS.Conclusion: VNS could protect against retinal I/R injury by downregulating TNF-α. Upregulation of VIP expression due to activation of the NOG-NTS-SSN-PPG neural circuit may underlie to the protective effects of VNS.

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“…It links the gut to the brain and plays a crucial role in appetite control through interaction of several gut hormones [7]. It is well-established that cholecystokinin (CCK), secreted in the intestines, plays a crucial role in anorectic effects through the vagus nerve [8], [9]. In the experiments described in this paper, CCK is used to activate signalling in the vagus nerve by intravenous injection.…”

Section: A Neurochemical Changes In the Vagus Nervementioning

confidence: 99%

A Convolutional Neural Network for Classification of Nerve Activity Based on Action Potential Induced Neurochemical Signatures

Roever

Mirza

Nikolić

et al. 2020

2020 IEEE International Symposium on Circuits and Systems (ISCAS)

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Neural activity results in chemical changes in the extracellular environment such as variation in pH or potassium/sodium ion concentration. Higher signal to noise ratio make neurochemical signals an interesting biomarker for closed-loop neuromodulation systems. For such applications, it is important to reliably classify pH signatures to control stimulation timing and possibly dosage. For example, the activity of the subdiaphragmatic vagus nerve (sVN) branch can be monitored by measuring extracellular neural pH. More importantly, gut hormone cholecystokinin (CCK)-specific activity on the sVN can be used for controllably activating sVN, in order to mimic the gut-brain neural response to food intake. In this paper, we present a convolutional neural network (CNN) based classification system to identify CCK-specific neurochemical changes on the sVN, from non-linear background activity. Here we present a novel feature engineering approach which enables, after training, a high accuracy classification of neurochemical signals using CNN.

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Influence of Cholecystokinin-8 on Compound Nerve Action Potentials from Ventral Gastric Vagus in Rats

Abstract: This approach of characterizing the vagus nerve can be used in closed loop systems to determine when to initiate VNS and also to tune the stimulation dose, which is patient-specific and changes over time.

Cited by 8 publications

References 37 publications

Role of Leptin in the Digestive System

Role of Leptin in the Digestive System

Vagal Nerve Stimulation Attenuates Ischemia-Reperfusion Induced Retina Dysfunction in Acute Ocular Hypertension

A Convolutional Neural Network for Classification of Nerve Activity Based on Action Potential Induced Neurochemical Signatures

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