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Computational Neuroscience and Compartmental Modeling
Published in Bahman Zohuri, Patrick J. McDaniel, Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Bahman Zohuri, Patrick J. McDaniel
Further analyses of Figure 3.7 indicate that Neurons are broadly classified as unipolar (A and B), bipolar (C), or multipolar (D). Unipolar neurons are found in invertebrate nervous systems. Pseudo-bipolar cells are typical of vertebrate sensory neurons. Their cell bodies are found in the dorsal root ganglia of the spinal cord. Many different types of sensory endings exist. Spinal motor neurons cell bodies lie in the spinal cord; their axons travel to the muscles they innervate. Very complex multipolar architectures are found in CNS interneurons. The dendritic field of the cerebellar Purkinje cells is amazingly complex.42
The neurotrophic factor rationale for using brief electrical stimulation to promote peripheral nerve regeneration in animal models and human patients
Published in Ze Zhang, Mahmoud Rouabhia, Simon E. Moulton, Conductive Polymers, 2018
An important aspect of the combined treatment of electrical stimulation and androgens was that the androgens enhanced both axon outgrowth and the rate of axon regeneration (Sharma et al. 2009). Prior to this demonstration, only a conditioning lesion had been shown to be effective in accelerating the regeneration rate; indeed, the discovery of the efficacy of the conditioning lesion in promoting axon regeneration was a major advance in the 1970s (Bisby and Keen 1984; Carlsen 1983; McQuarrie 1978, 1981; McQuarrie et al. 1977; Oudega et al. 1994). By definition, the conditioning lesion is a crush injury induced prior to or at the same time as the “test” injury, with an injury 3 or more days prior to the test injury being the most effective in accelerating axon regeneration after the test injury itself. This efficacy in promoting regeneration of axons within the peripheral nervous system was also demonstrated within the central nervous system, with a crush of a peripheral nerve promoting regeneration of dorsal root ganglion sensory axons that were transected within the central nervous system (Neumann and Woolf 1999). In contrast, electrical stimulation of the peripheral nerve accelerated axon outgrowth but not the rate of regeneration of the central axons (Gordon et al. 2009). Cyclic AMP (cAMP), a key intermediary in the accelerated rate of regeneration by a conditioning lesion, may also be involved in the mechanism by which electrical stimulation accelerates axon outgrowth. Administration of rolipram that elevates cAMP by inhibiting phosphodiesterase, the enzyme that degrades cAMP, also promoted axon outgrowth across a suture line (Udina et al. 2010). It remains to be seen whether the efficacy of rolipram in promoting axon regeneration involves either or both accelerated axon outgrowth and an increased rate of regeneration.
Membrane Models
Published in Joseph D. Bronzino, Donald R. Peterson, Biomedical Engineering Fundamentals, 2019
Primary Afferents and Related Efferents A model comprising a fast sodium current, a delayed rectier potassium current, a calcium current, and a calcium-dependent potassium current was used to model primary aerents as well as interneurons and eerent neurons connected to the aerents by Saxena et al. (1997). A modication of the HH model was used in Amir et al. (2002) to model A-type dorsal root ganglion neuron cell bodies.
Effects of a 16-week Tai Chi intervention on cutaneous sensitivity and proprioception among older adults with and without sensory loss
Published in Research in Sports Medicine, 2021
Teng Zhang, Min Mao, Wei Sun, Li Li, Yan Chen, Cui Zhang, Xinyan Zhang, Qipeng Song
The significant interaction between the two groups in the heel supported our first hypothesis that TC improved cutaneous sensitivity at more sites among the older adults with sensory loss. PN, including sensory loss, caused a range of symptoms on the basis of the distribution and types of nerve fibres involved. In mammals, discriminative light touch perception was mediated by primary sensory neurons, namely, low-threshold mechanoreceptors (Fleming & Luo, 2013; Li et al., 2019). Cell bodies are located in the dorsal root ganglia and trigeminal ganglia, which extend a central projection innervating the spinal cord and brain stem and peripheral projection innervating the specialized mechanosensory end organs (Fleming & Luo, 2013). Among the older adults with sensory loss, peripheral nerves may have undergone morphological changes (Crone & Krarup, 2013). Major pathological changes in peripheral nerve fibres include axonal loss and demyelination. In most cases of demyelinating neuropathy, considerable axonal loss is found (Crone & Krarup, 2013). Therefore, the effects of TC intervention may be enhanced among the older adults with sensory loss. It is recommended the older adults begin TC exercises as early as possible.
Advanced methods of spinal stimulation in the treatment of chronic pain: pulse trains, waveforms, frequencies, targets, and feedback loops
Published in Expert Review of Medical Devices, 2019
Ankit Maheshwari, Jason E. Pope, Timothy R. Deer, Steven Falowski
The dorsal root ganglion houses primary sensory neurons of all modalities. It has been identified as an important site of aberrant activity in neuropathic pain. Electrical stimulation of the dorsal root ganglion has a potential to reduce neuronal excitability as well as modulating ectopic discharges. Since the time of our last review, there has been an increase in the application of dorsal root ganglion stimulation and clinical outcome studies have demonstrated its effectiveness for numerous chronic neuropathic pain conditions such as complex regional pain syndrome, post-herniorrhaphy groin pain, radicular pain (Table 6). Typically, this modality has been used for the treatment of distal neuropathic pain conditions which, in the past have been hard to treat with dorsal column stimulation.
Contact area affects frequency-dependent responses to vibration in the peripheral vascular and sensorineural systems
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Kristine Krajnak, G. R. Miller, Stacey Waugh
One day following the final exposure, rats were anesthetized using pentobarbital (100 mg/kg) and exsanguinated by cardiac puncture. Ventral tail arteries were dissected from the C15-18 regions of the tail. These segments were selected because the biodynamic response (amplitude of the tail/amplitude of the vibrating platform) to vibration is frequency-dependent in these regions of the tail; with the response at 62.5 Hz being around 1 (unity) and the response at 250 Hz being between two and three (i.e. resonance (Welcome et al. 2008)). The ventral tail artery, dissected from the C15-16 region of the tail was immediately placed into a cryovial, frozen in liquid nitrogen, and stored at −80°C until RNA was isolated. The C17-18 segments of each tail were placed in 15 ml conical tubes and immersion fixed overnight using 4% paraformaldehyde + 0.1M phosphate buffer, pH 7.3. The next morning, the ventral-tail artery was dissected from the fixed segment and placed in 2 ml cryovials containing 1.5 ml 10 mM phosphate buffered saline pH 7.4. Vials were stored at 4°C until processed for morphological analyses. Nerve samples were also collected from the C15-16 and C17-18 regions, along with dorsal root ganglia (DRG) adjacent to the L4-6 region of the spinal cord. These tissues were placed into cryovials, immediately frozen in liquid nitrogen and stored at −80°C until used for RT-PCR or measurement anti-oxidant enzymes.