Electrical activity of the sensory afferent pathway in the enteric nervous system

In this paper we develop a mathematical model for the electrical activity of the afferent pathway, formed from the coupled primary and secondary sensory neurons. The primary sensory neuron possesses the electrical properties of AH neurons and morphological characteristics of Dogiel type II neurons; the secondary sensory neuron displays the tonic type of electrical behavior and has morphological features of Dogiel type III neurons. Free nerve endings of the mechanoreceptor form the receptive field of the pathway. Based on the general principles of the Hodgkin-Huxley description of excitable cells, the model simulates the following sequence of events: stretch of the receptive field initiates the dendritic potential at the mechanoreceptors; the excitation causes soma action potential development at the primary sensory neuron which is followed by soma action potential generation at the secondary sensory neuron. Numerical calculations have shown that the model is capable of reproducing different electrical patterns within the pathway under normal physiological conditions and after treatment with charybdotoxin, iberiotoxin, tetrodotoxin, ω-conotoxin GVIA, A1-A2 purinoceptor agonists, a protein kinase C activator, and a δ-opioid receptor agonist. Comparison of the computational results with the results of experiments conducted on the neurons of the submucous and myenteric plexi of the small bowel demonstrates their good qualitative and quantitative agreement. © Springer-Verlag 1996

Simulations of Myenteric Neuron Dynamics in Response to Mechanical Stretch

Background. Intestinal sensitivity to mechanical stimuli has been studied intensively in visceral pain studies. The ability to sense different stimuli in the gut and translate these to physiological outcomes relies on the mechanosensory and transductive capacity of intrinsic intestinal nerves. However, the nature of the mechanosensitive channels and principal mechanical stimulus for mechanosensitive receptors are unknown. To be able to characterize intestinal mechanoelectrical transduction, that is, the molecular basis of mechanosensation, comprehensive mathematical models to predict responses of the sensory neurons to controlled mechanical stimuli are needed. This study aims to develop a biophysically based mathematical model of the myenteric neuron with the parameters constrained by learning from existing experimental data. Findings. The conductance-based single-compartment model was selected. The parameters in the model were optimized by using a combination of hand tuning and automated estimation. Using the optimized parameters, the model successfully predicted the electrophysiological features of the myenteric neurons with and without mechanical stimulation. Conclusions. The model provides a method to predict features and levels of detail of the underlying physiological system in generating myenteric neuron responses. The model could be used as building blocks in future large-scale network simulations of intrinsic primary afferent neurons and their network

Electrical activity of the sensory afferent pathway in the enteric nervous system

In this paper we develop a mathematical model for the electrical activity of the afferent pathway, formed from the coupled primary and secondary sensory neurons. The primary sensory neuron possesses the electrical properties of AH neurons and morphological characteristics of Dogiel type II neurons; the secondary sensory neuron displays the tonic type of electrical behavior and has morphological features of Dogiel type III neurons. Free nerve endings of the mechanoreceptor form the receptive field of the pathway. Based on the general principles of the Hodgkin-Huxley description of excitable cells, the model simulates the following sequence of events: stretch of the receptive field initiates the dendritic potential at the mechanoreceptors; the excitation causes soma action potential development at the primary sensory neuron which is followed by soma action potential generation at the secondary sensory neuron. Numerical calculations have shown that the model is capable of reproducing different electrical patterns within the pathway under normal physiological conditions and after treatment with charybdotoxin, iberiotoxin, tetrodotoxin, ω-conotoxin GVIA, A1-A2 purinoceptor agonists, a protein kinase C activator, and a δ-opioid receptor agonist. Comparison of the computational results with the results of experiments conducted on the neurons of the submucous and myenteric plexi of the small bowel demonstrates their good qualitative and quantitative agreement. © Springer-Verlag 1996

Electrical activity of the sensory afferent pathway in the enteric nervous system

In this paper we develop a mathematical model for the electrical activity of the afferent pathway, formed from the coupled primary and secondary sensory neurons. The primary sensory neuron possesses the electrical properties of AH neurons and morphological characteristics of Dogiel type II neurons; the secondary sensory neuron displays the tonic type of electrical behavior and has morphological features of Dogiel type III neurons. Free nerve endings of the mechanoreceptor form the receptive field of the pathway. Based on the general principles of the Hodgkin-Huxley description of excitable cells, the model simulates the following sequence of events: stretch of the receptive field initiates the dendritic potential at the mechanoreceptors; the excitation causes soma action potential development at the primary sensory neuron which is followed by soma action potential generation at the secondary sensory neuron. Numerical calculations have shown that the model is capable of reproducing different electrical patterns within the pathway under normal physiological conditions and after treatment with charybdotoxin, iberiotoxin, tetrodotoxin, ω-conotoxin GVIA, A1-A2 purinoceptor agonists, a protein kinase C activator, and a δ-opioid receptor agonist. Comparison of the computational results with the results of experiments conducted on the neurons of the submucous and myenteric plexi of the small bowel demonstrates their good qualitative and quantitative agreement. © Springer-Verlag 1996

Electrical activity of the sensory afferent pathway in the enteric nervous system

In this paper we develop a mathematical model for the electrical activity of the afferent pathway, formed from the coupled primary and secondary sensory neurons. The primary sensory neuron possesses the electrical properties of AH neurons and morphological characteristics of Dogiel type II neurons; the secondary sensory neuron displays the tonic type of electrical behavior and has morphological features of Dogiel type III neurons. Free nerve endings of the mechanoreceptor form the receptive field of the pathway. Based on the general principles of the Hodgkin-Huxley description of excitable cells, the model simulates the following sequence of events: stretch of the receptive field initiates the dendritic potential at the mechanoreceptors; the excitation causes soma action potential development at the primary sensory neuron which is followed by soma action potential generation at the secondary sensory neuron. Numerical calculations have shown that the model is capable of reproducing different electrical patterns within the pathway under normal physiological conditions and after treatment with charybdotoxin, iberiotoxin, tetrodotoxin, ω-conotoxin GVIA, A1-A2 purinoceptor agonists, a protein kinase C activator, and a δ-opioid receptor agonist. Comparison of the computational results with the results of experiments conducted on the neurons of the submucous and myenteric plexi of the small bowel demonstrates their good qualitative and quantitative agreement. © Springer-Verlag 1996