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Anatomy and Function of the Intrathoracic Neurons Regulating the Mammalian Heart
Published in Irving H. Zucker, Joseph P. Gilmore, Reflex Control of the Circulation, 2020
Excitatory Amino Acid Receptors. When the excitatory amino acids glutamate or aspartate are injected into specific loci within an acutely decentralized stellate or middle cervical ganglion, cardiac chronotropism and/or inotropism can be augmented (Butler et al., 1989). These data imply that amino acids can also directly or indirectly activate the efferent postganglionic sympathetic neurons that innervate the heart. Neurons that can be activated by these amino acids are located throughout the stellate and middle cervical ganglia. Thus a number of chemicals appear to be capable of modifying intrathoracic ganglionic cardiac neurons.
Choreoathetosis
Published in Richard A. Jonas, Jane W. Newburger, Joseph J. Volpe, John W. Kirklin, Brain Injury and Pediatric Cardiac Surgery, 2019
David L. Wessel, Adre J. du Plessis
It remains unclear why the child with cyanotic heart disease who has progressed beyond early infancy appears to be more at risk to develop choreoathetosis. One possibility is increased susceptibility of the basal ganglia to injury after chronic hypoxia. Chaves and Scaltsas-Persson11 proposed that an acute insult during CPB/DHCA superimposed on chronic hypoxemia results in injury to vulnerable areas of the basal ganglia. Alternatively, time may be required to develop systemic-pulmonary collaterals and a cerebral steal capacity that is not as significant at an earlier age. Neuronal maturational differences might predispose the basal ganglia to increasing susceptibility at this age. Age-specific differences in regional cerebral metabolic rates for glucose have recently been demonstrated by positron emission tomography.22 It is still unknown why the basal ganglia are so susceptible to injury in this setting, and the exact mechanism of injury is also uncertain although an anoxic ischemic injury is most likely. Wical and Tomasi10 have suggested that glutamate or other excitatory amino acid neurotoxicity may lead to cellular dysfunction. The potential role of excitatory amino acids in the pathogenesis of anoxic-ischemic brain injury is currently the topic of active investigation,23,24 and the observation of a transient excessive glutamatergic innervation of the globus pallidus in the human infant is of particular interest in this regard.25
Overview of Neurotransmission: Relationship to the Action of Antiepileptic Drugs
Published in Carl L. Faingold, Gerhard H. Fromm, Drugs for Control of Epilepsy:, 2019
Glutamate and aspartate are excitatory amino acid neurotransmitters. Glutamate is found in higher concentrations than any other free amino acid in the CNS, being three or four times higher than taurine, or aspartate, and six times higher than GABA.75 The excitant amino acid neurotransmitters are the subject of intense current investigation in part because of their abundance and importance in so many neural pathways and in part because of studies implicating them in such pathological conditions as epilepsy, post-anoxic cell loss, and neurotoxicity (excitotoxicity).
A mechanistic overview of spinal cord injury, oxidative DNA damage repair and neuroprotective therapies
Published in International Journal of Neuroscience, 2023
Jaspreet Kaur, Aditya Mojumdar
A pathological condition occurs by over-activation of glutamatergic receptors leading to neuronal cell death, the mechanism is known as excitotoxicity [38, 42–44]. At the normal synapse level, the glutamate excitation is efficiently terminated by glutamate uptake mechanisms of nerve and glial cells [45]. There are specific transporter proteins in the cells that uptake the glutamate by using the electrochemical potential gradient of Na+ and K+ ions. It is an efficient mechanism of maintaining a higher intracellular glutamate concentration compared to the extracellular level. Several glutamate transporter proteins, excitatory amino acid transporters 1 to 5, have been studied and reviewed [46,47]. The mainly studied excitatory amino acid receptors are – N-methyl-D-aspartate (NMDA) receptors, α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) and kainate receptors. In physiologic conditions, these ion channels facilitate glutamate-mediated synaptic transmission. They have been studied and reviewed in detail [48–51].
Nose-to-brain delivery of borneol modified tanshinone IIA nanoparticles in prevention of cerebral ischemia/reperfusion injury
Published in Drug Delivery, 2021
Luting Wang, Lin Xu, Junfeng Du, Xiao Zhao, Mei Liu, Jianfang Feng, Kaili Hu
TSA is the major active ingredient of a Traditional Chinese Medicine (TCM) Salvia miltiorrhiza, which has been widely used for the treatment of cerebrovascular diseases (Han et al., 2008). Modern clinical and pharmacological studies have shown a variety of activities of TSA such as significant inhibition of the degree of peroxidation, decrease the toxicity of excitatory amino acid, inhibit Ca2+ overload, decrease NO release, inhibit mitochondrial damage, decrease oxygen free radicals level, regulate the immunoinflammatory process, and inhibit apoptosis (Dong et al., 2018). Besides the notable curative effects for cardiovascular and cerebrovascular diseases, TSA also indicates various activities that might be effective in protection for CIRI (Tang et al., 2010; Liu et al., 2010a, 2011). However, due to the poor solubility of TSA, rapid plasma clearance, and P-gp efflux, it is difficult to pass through the blood–brain barrier (BBB), which greatly limits its therapeutic effect on CIRI. In this study, polymeric NPs were chosen to improve the brain targeting of TSA after IN administration. The variability of polymer carrier can give drug delivery system many new characteristics. Polyester materials are widely used because of their biodegradability, good biocompatibility, and safety. Free design of polymer chain length can produce different particle size, drug delivery capacity, and biological effects.
Discovery of differentially expressed genes in the intestines of Pelteobagrus vachellii within a light/dark cycle
Published in Chronobiology International, 2020
Chuanjie Qin, Jiaxian Sun, Jun Wang, Yongwang Han, He Yang, Qingchao Shi, Yunyun Lv, Peng Hu
Moreover, a diurnal rhythmicity was noted for peptide absorption, for example, in nocturnal animals, the L-histidine absorption peak occurs during the dark phase(Furuya and Yugari 1974), which is coincident with higher expression levels of peptide transporter HPEPT1 (PEPT1) in the the dark compared with that in the light (Pan et al. 2002). In this study, b(0,+)-type amino acid transporter 1, sodium-coupled neutral amino acid transporter B, sodium-dependent neutral amino acid transporter 3, and excitatory amino acid transporter 1, all displayed upregulation at night, which contrasted with that of low affinity cationic amino acid transporter 2, a large neutral amino acids transporter. Excitatory amino acid transporter 1 is a sodium-dependent, high-affinity amino acid transporter that mediates the uptake of L-glutamate, L-aspartate, and D-aspartate (Arriza et al. 1994). The high-affinity transport of large neutral amino acids (e.g., phenylalanine, tyrosine, leucine, arginine, and tryptophan) is affected by sodium-independent, large neutral amino acids transporters. The peak time of mRNA expression was different for digestive enzymes and amino acid transporters within a light/dark cycle, which might suggest that the digestion and absorption of different amino acids was occurred at different times. Similarly, Senegalese sole (Solea senegalensis) showed their highest post-larval protein retention capacities when fed at nighttime (Marinho et al. 2014).