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Sedation and Restraint for Standing Procedures
Published in Michele Barletta, Jane Quandt, Rachel Reed, Equine Anesthesia and Pain Management, 2023
Mechanism of action. Agonism of alpha-2 adrenoreceptors in the central nervous system (CNS). Inhibition of norepinephrine and dopamine storage and release.Decrease in firing rate of central and peripheral neurons.Decrease in CNS sympathetic output and peripheral sympathetic tone; increase in parasympathetic tone.Alpha-1 effects functionally antagonize the hypnotic effects of alpha-2 antagonism.
Epilogue: Discussion, Evaluation and Future Research
Published in Harald Maurer, Cognitive Science, 2021
Here, u(x,t) is interpreted as a neural field representing the local activity of a population of neurons at position n ∈ R. The second term on the right represents the synaptic input, with f o u interpreted as the firing rate function. There are several natural choices for the firing rate function. With a statistical mechanics approach to formulating mean-field neural equations, this all or nothing response is replaced by a smooth sigmoidal form (Wilson and Cowan 1972, Amari 1972), For an arbitrary firing rate response the model (11.1) is naturally written in the form
Brain Stimulation Therapies
Published in Bahman Zohuri, Patrick J. McDaniel, Electrical Brain Stimulation for the Treatment of Neurological Disorders, 2019
Bahman Zohuri, Patrick J. McDaniel
Following a series of new experiments and advanced theoretical studies, the Israeli physicists, led by Prof. Ido Kanter, of the Department of Physics and Gonda (Goldschmied) Multidisciplinary Brain Research Center at Bar-Ilan University, have demonstrated that each neuron has a maximal firing rate that is much lower than previously assumed. Hence, when stimulated too fast, neuronal response failures occur. “Neurons are like people,” said Prof. Kanter. “Stuttering occurs when we speak too fast, errors occur when we type too fast, and confusion emerges when we learn too fast.”
Consciousness in a Rotor? Science and Ethics of Potentially Conscious Human Cerebral Organoids
Published in AJOB Neuroscience, 2023
Federico Zilio, Andrea Lavazza
A recent study showed for the first time that cortical organoids can spontaneously develop periodic and regular oscillatory network electrical activity very similar to the EEG patterns of preterm babies (Trujillo et al. 2019). Even in the absence of external or subcortical inputs, ten-month-old HCOs can grow according to a specific genetic program, like all human beings, and manifest complex brain activity recorded with a multi-microelectrode array. “The spontaneous network formation displayed periodic and regular oscillatory events that were dependent on glutamatergic and GABAergic signaling” (ibidem). The firing rate, up to two or three per second, and the kind of waves—gamma, alpha, and delta—are all typical signs of a vital human brain. Indeed, a machine-learning model based on a preterm newborn’s EEG (ranging from 24–38 weeks) features was able to predict the organoid culture’s age based on the latter’s electrical activity. The software found no significant differences in EEG between the patterns of preterm infants and the patterns of HCOs. These results, although very relevant, do not mean that the recorded activity patterns give rise to the same subjective states as that can be found in preterm babies, such as pain sensations that fetuses after 24 weeks can likely experience.
5-HT1B receptor-AC-PKA signal pathway in the lateral habenula is involved in the regulation of depressive-like behaviors in 6-hydroxydopamine-induced Parkinson’s rats
Published in Neurological Research, 2023
Guo Yi Tang, Run Jia Wang, Yuan Guo, Jian Liu
In this study, only rats verified the location of the cannula, recording site, probe, and a near complete loss of TH immunoreactive (TH-ir) neurons in the right SNc were used to analyze behavioral, electrophysiological, and microdialysis data. Additionally, only rats with reduced striatal DA by >90% were considered for the analysis of Western blotting data. For electrophysiological data, basal firing activity of LHb neurons was recorded for 5 min before any treatment, and the following parameters were calculated: (i) mean firing rate; and (ii) coefficient of variation (COV, the ratio between standard deviation of the interspike interval and mean interspike interval, reflecting the degree of regularity of neuronal firing) [34]. After intra-LHb injection of CP93129 or SB216641, changes in the firing rate of the neurons were analyzed per 5 min epoch up to 25 min. The COV of the neurons was compared in a period of 5 min before and after injection of the drugs. For microdialysis data, the average of three consecutive dialysates before injection of the drugs was defined as 100% of basal transmitter release. In TH immunohistochemistry, three representative sections per rat were used to count TH-ir neurons in the SNc and VTA.
The effect of experimental shoulder pain on contralateral muscle force and activation
Published in Physiotherapy Theory and Practice, 2021
Scott K. Stackhouse, Brett A. Sweitzer, Philip W. McClure
Shoulder pain in the general population has a point prevalence between 7% and 26% (Luime et al., 2004), and painful conditions of the shoulder have been shown to impair muscle function and to be related to outcomes (Andersen, Holtermann, Jorgensen, and Sjogaard, 2008; Celik, Sirmen, and Demirhan, 2011; Joensen, Couppe, and Bjordal, 2009; MacDermid et al., 2004; McClure et al., 2004; Merolla et al., 2010; Sokk et al., 2007). The shoulder girdle is heavily reliant on muscle action to maintain stability, and abnormal EMG activation patterns of muscles surrounding the shoulder have been well documented in patients with painful shoulder conditions (Bigliani and Levine, 1997; Chester, Smith, Hooper, and Dixon, 2010; Glousman et al., 1988; Graichen et al., 2001; Lucas, Rich, and Polus, 2010; Ludewig and Cook, 2000). Therefore, experiencing shoulder pain may adversely affect a patient’s ability to recruit and drive the firing rate of key muscle groups.