Dexmedetomidine, which is an α2 adrenergic receptor agonist with sedative, analgesic, anxiolytic and anti-sympathetic effects, has become a widely used drug in clinical anesthesia and intensive care unit (ICU). Compared with other drugs in the department of anesthesiology, dexmedetomidine has no obvious respiratory depression and no obvious hemodynamic changes, and can significantly reduce the dosage of sedative and analgesic drugs when combined with other anesthetics. In clinical applications, dexmedetomidine has been found to induce a sedative response that is associated with rapid arousal. Dexmedetomidine is traditionally thought to act through α2 adrenergic receptors to lower blood pressure, dilate blood vessels and lower heart rate, but it is unclear how it affects neural circuits in the brain. In recent years, there has been an increasing number of studies on the mechanism of action of dexmedetomidine, which has confirmed that the ventrolateral preoptic nucleus (VLPO), locus coeruleus (LC) and ventral tegmental area (VTA) of the hypothalamus are involved in the sedation mediated by dexmedetomidine, the dorsal root ganglion (DRG) and superior cervical ganglion (SCG) are involved in dexmedetomidine-mediated analgesia, and the hypothalamic preoptic area (PO) and hypothalamic paraventricular nucleus (PVN) are involved in the changes in body temperature and water-electrolyte balance mediated by dexmedetomidine, providing a new direction for understanding the mechanism of dexmedetomidine in the central nervous system.
SONG Yifan, JIANG Linhao, YANG Qianzi, LUO Yan. Research progress in the central nervous system mechanism of dexmedetomidine. Journal of Shanghai Jiao Tong University (Medical Science)[J], 2024, 44(5): 626-634 doi:10.3969/j.issn.1674-8115.2024.05.011
右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1]。1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2]。在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用。临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域。基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值。因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义。本文就近年来右美托咪定在中枢神经的作用机制做一综述。
在哺乳动物的新生儿时期,发育中的大脑,尤其是海马的齿状回,要经历许多的神经发生、突触发生和连接,这些是学习和记忆的基础,在此期间,海马受到外部刺激,例如感染、氧化应激、毒素均可能导致广泛且通常不可逆的神经元损伤以及可塑性受损[75]。在新生大鼠中使用高氧介导的脑损伤模型探究右美托咪定对齿状回神经发生的影响,发现暴露于高氧条件下显著降低了新生大鼠海马组织的增殖能力以及神经元标志物和转录因子的表达,神经可塑性调节因子也明显下降;然而,大鼠暴露在高氧前单次注射右美托咪定进行预处理,可以上调神经元分化、增殖、迁移和成熟[76]。对于新生后的缺氧大鼠,右美托咪定治疗后,缺氧后认知功能损害减轻,受损突触恢复、突触后密度蛋白-95(postsynaptic density protein-95,PSD95)和突触素蛋白表达增加[77]。由此可见,右美托咪定可以改善神经的可塑性,减轻其他不利影响导致的神经损伤。
The original manuscript was drafted by SONG Yifan and JIANG Linhao. The revision of the manuscript was reviewed and guided by YANG Qianzi and LUO Yan. All the authors have read the last version of paper and consented for submission.
利益冲突声明
所有作者声明不存在利益冲突。
COMPETING INTERESTS
All authors disclose no relevant conflict of interests.
CHIMA A M, MAHMOUD M A, NARAYANASAMY S. What is the role of dexmedetomidine in modern anesthesia and critical care?[J]. Adv Anesth, 2022, 40(1): 111-130.
EBERT T J, HALL J E, BARNEY J A, et al. The effects of increasing plasma concentrations of dexmedetomidine in humans[J]. Anesthesiology, 2000, 93(2): 382-394.
DE ZEN L, DIVISIC A, MOLINARO G, et al. Dexmedetomidine at home for intractable dystonia and insomnia in children with special needs: a case series[J]. J Pain Symptom Manage, 2023, 66(6): e653-e657.
MOON E J, KO I G, KIM S E, et al. Dexmedetomidine ameliorates sleep deprivation-induced depressive behaviors in mice[J]. Int Neurourol J, 2018, 22(Suppl 3): S139-S146.
HWANG L, KO I G, JIN J J, et al. Dexmedetomidine ameliorates memory impairment in sleep-deprived mice[J]. Anim Cells Syst (Seoul), 2019, 23(6): 371-379.
ZHAI Q, ZHANG Y, YE M, et al. Reducing complement activation during sleep deprivation yields cognitive improvement by dexmedetomidine[J]. Br J Anaesth, 2023, 131(3): 542-555.
NELSON L E, LU J, GUO T Z, et al. The alpha2-adrenoceptor agonist dexmedetomidine converges on an endogenous sleep-promoting pathway to exert its sedative effects[J]. Anesthesiology, 2003, 98(2): 428-436.
SZUMITA P M, BAROLETTI S A, ANGER K E, et al. Sedation and analgesia in the intensive care unit: evaluating the role of dexmedetomidine[J]. Am J Health Syst Pharm, 2007, 64(1): 37-44.
NACIF-COELHO C, CORREA-SALES C, CHANG L L, et al. Perturbation of ion channel conductance alters the hypnotic response to the alpha 2-adrenergic agonist dexmedetomidine in the locus coeruleus of the rat[J]. Anesthesiology, 1994, 81(6): 1527-1534.
BARENDS C R M, ABSALOM A, VAN MINNEN B, et al. Dexmedetomidine versus midazolam in procedural sedation. A systematic review of efficacy and safety[J]. PLoS One, 2017, 12(1): e0169525.
CHIU T H, CHEN M J, YANG Y R, et al. Action of dexmedetomidine on rat locus coeruleus neurones: intracellular recording in vitro[J]. Eur J Pharmacol, 1995, 285(3): 261-268.
SONG A H, KUCYI A, NAPADOW V, et al. Pharmacological modulation of noradrenergic arousal circuitry disrupts functional connectivity of the locus ceruleus in humans[J]. J Neurosci, 2017, 37(29): 6938-6945.
VOGT B A, HOF P R, FRIEDMAN D P, et al. Norepinephrinergic afferents and cytology of the macaque monkey midline, mediodorsal, and intralaminar thalamic nuclei[J]. Brain Struct Funct, 2008, 212(6): 465-479.
AKEJU O, LOGGIA M L, CATANA C, et al. Disruption of thalamic functional connectivity is a neural correlate of dexmedetomidine-induced unconsciousness[J]. eLife, 2014, 3: 04499.
WALSH J J, HAN M H. The heterogeneity of ventral tegmental area neurons: projection functions in a mood-related context[J]. Neuroscience, 2014, 282: 101-108.
TAYLOR N, CHEMALI J, BROWN E, et al. Activation of D1 dopamine receptors induces emergence from isoflurane general anesthesia[J]. Anesthesiology, 2013, 118(1): 30-39.
QIU G L, WU Y, YANG Z Y, et al. Dexmedetomidine activation of dopamine neurons in the ventral tegmental area attenuates the depth of sedation in mice[J]. Anesthesiology, 2020, 133(2): 377-392.
LU J, GRECO M A, SHIROMANI P, et al. Effect of lesions of the ventrolateral preoptic nucleus on NREM and REM sleep[J]. J Neurosci, 2000, 20(10): 3830-3842.
GAUS S E, STRECKER R E, TATE B A, et al. Ventrolateral preoptic nucleus contains sleep-active, galaninergic neurons in multiple mammalian species[J]. Neuroscience, 2002, 115(1): 285-294.
ARRIGONI E, FULLER P M. The sleep-promoting ventrolateral preoptic nucleus: what have we learned over the past 25 years?[J]. Int J Mol Sci, 2022, 23(6): 2905.
TSUTSUMI Y, MIZUNO Y, HAQUE T, et al. Widespread corticopetal projections from the oval paracentral nucleus of the intralaminar thalamic nuclei conveying orofacial proprioception in rats[J]. Brain Struct Funct, 2021, 226(4): 1115-1133.
BAKER R, GENT T C, YANG Q Z, et al. Altered activity in the central medial thalamus precedes changes in the neocortex during transitions into both sleep and propofol anesthesia[J]. J Neurosci, 2014, 34(40): 13326-13335.
YAMAKITA S, MATSUDA M, YAMAGUCHI Y, et al. Dexmedetomidine prolongs levobupivacaine analgesia via inhibition of inflammation and p38 MAPK phosphorylation in rat dorsal root ganglion[J]. Neuroscience, 2017, 361: 58-68.
REBOLLAR R E, GARCÍA PALACIOS M V, FERNÁNDEZ RIOBÓ M C, et al. Dexmedetomidine and perioperative analgesia in children[J]. Rev Esp Anestesiol Reanim (Engl Ed), 2022, 69(8): 487-492.
GRAPE S, KIRKHAM K R, FRAUENKNECHT J, et al. Intra-operative analgesia with remifentanil vs. dexmedetomidine: a systematic review and meta-analysis with trial sequential analysis[J]. Anaesthesia, 2019, 74(6): 793-800.
ZHU X, TANG H D, DONG W Y, et al. Distinct thalamocortical circuits underlie allodynia induced by tissue injury and by depression-like states[J]. Nat Neurosci, 2021, 24(4): 542-553.
ARAKAWA H, SUZUKI A, ZHAO S X, et al. Thalamic NMDA receptor function is necessary for patterning of the thalamocortical somatosensory map and for sensorimotor behaviors[J]. J Neurosci, 2014, 34(36): 12001-12014.
BORDI F, QUARTAROLI M. Modulation of nociceptive transmission by NMDA/glycine site receptor in the ventroposterolateral nucleus of the thalamus[J]. Pain, 2000, 84(2/3): 213-224.
CHEN J Y, LI H J, LIM G, et al. Different effects of dexmedetomidine and midazolam on the expression of NR2B and GABAA-α1 following peripheral nerve injury in rats[J]. IUBMB Life, 2018, 70(2): 143-152.
YOU H J, LEI J, XIAO Y, et al. Pre-emptive analgesia and its supraspinal mechanisms: enhanced descending inhibition and decreased descending facilitation by dexmedetomidine[J]. J Physiol, 2016, 594(7): 1875-1890.
ZHANG Z J, GUO J S, LI S S, et al. TLR8 and its endogenous ligand miR-21 contribute to neuropathic pain in murine DRG[J]. J Exp Med, 2018, 215(12): 3019-3037.
BERTA T, QADRI Y, TAN P H, et al. Targeting dorsal root ganglia and primary sensory neurons for the treatment of chronic pain[J]. Expert Opin Ther Targets, 2017, 21(7): 695-703.
WAN Y, YU Y, PAN X X, et al. Inhibition on acid-sensing ion channels and analgesic activities of flavonoids isolated from dragon′s blood resin[J]. Phytother Res, 2019, 33(3): 718-727.
WEI S, QIU C Y, JIN Y, et al. Dexmedetomidine inhibits ASIC activity via activation of α2A adrenergic receptors in rat dorsal root ganglion neurons[J]. Front Pharmacol, 2021, 12: 685460.
HARDING E K, FUNG S W, BONIN R P. Insights into spinal dorsal horn circuit function and dysfunction using optical approaches[J]. Front Neural Circuits, 2020, 14: 31.
LI J, TANG H Z, TU W F. Mechanism of dexmedetomidine preconditioning on spinal cord analgesia in rats with functional chronic visceral pain[J]. Acta Cir Bras, 2022, 37(2): e370203.
LU Y C, LIN B H, ZHONG J M. The therapeutic effect of dexmedetomidine on rat diabetic neuropathy pain and the mechanism[J]. Biol Pharm Bull, 2017, 40(9): 1432-1438.
PANG J, ZHANG S M, KONG Y, et al. The effect of dexmedetomidine on expression of neuronal nitric oxide synthase in spinal dorsal cord in a rat model with chronic neuropathic pain[J]. Arq Neuropsiquiatr, 2023, 81(3): 233-239.
JÄNIG W, HÄBLER H J. Neurophysiological analysis of target-related sympathetic pathways: from animal to human: similarities and differences[J]. Acta Physiol Scand, 2003, 177(3): 255-274.
YANG L, TANG J, DONG J, et al. Alpha2-adrenoceptor-independent inhibition of acetylcholine receptor channel and sodium channel by dexmedetomidine in rat superior cervical ganglion neurons[J]. Neuroscience, 2015, 289: 9-18.
BRUMMETT C M, HONG E K, JANDA A M, et al. Perineural dexmedetomidine added to ropivacaine for sciatic nerve block in rats prolongs the duration of analgesia by blocking the hyperpolarization-activated cation current[J]. Anesthesiology, 2011, 115(4): 836-843.
MARHOFER D, KETTNER S C, MARHOFER P, et al. Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: a volunteer study[J]. Br J Anaesth, 2013, 110(3): 438-442.
WANG Z H, ZHOU W, DONG H P, et al. Dexmedetomidine pretreatment inhibits cerebral ischemia/reperfusion-induced neuroinflammation via activation of AMPK[J]. Mol Med Rep, 2018, 18(4): 3957-3964.
ZHANG Y Z, ZHOU Z C, SONG C Y, et al. The protective effect and mechanism of dexmedetomidine on diabetic peripheral neuropathy in rats[J]. Front Pharmacol, 2020, 11: 1139.
HU B, TIAN T, LI X T, et al. Dexmedetomidine postconditioning attenuates myocardial ischemia/reperfusion injury by activating the Nrf2/Sirt3/SOD2 signaling pathway in the rats[J]. Redox Rep, 2023, 28(1): 2158526.
LIN S, ZHOU G L, SHAO W, et al. Impact of dexmedetomidine on amino acid contents and the cerebral ultrastructure of rats with cerebral ischemia-reperfusion injury[J]. Acta Cir Bras, 2017, 32(6): 459-466.
ZHU Y L, LI S H, LIU J Y, et al. Role of JNK signaling pathway in dexmedetomidine post-conditioning-induced reduction of the inflammatory response and autophagy effect of focal cerebral ischemia reperfusion injury in rats[J]. Inflammation, 2019, 42(6): 2181-2191.
FENG X Y, MA W W, ZHU J, et al. Dexmedetomidine alleviates early brain injury following traumatic brain injury by inhibiting autophagy and neuroinflammation through the ROS/Nrf2 signaling pathway[J]. Mol Med Rep, 2021, 24(3): 661.
YANG L, WU H Y, YANG F L, et al. Identification of candidate genes and pathways in dexmedetomidine-induced neuroprotection in rats using RNA sequencing and bioinformatics analysis[J]. Ann Palliat Med, 2021, 10(1): 372-384.
ENDESFELDER S, MAKKI H, VON HAEFEN C, et al. Neuroprotective effects of dexmedetomidine against hyperoxia-induced injury in the developing rat brain[J]. PLoS One, 2017, 12(2): e0171498.
CHEN X H, CHEN D T, LI Q, et al. Dexmedetomidine alleviates hypoxia-induced synaptic loss and cognitive impairment via inhibition of microglial NOX2 activation in the hippocampus of neonatal rats[J]. Oxid Med Cell Longev, 2021, 2021: 6643171.
CHANG M, CHO S A, LEE S J, et al. Comparison of the effects of dexmedetomidine and propofol on hypothermia in patients under spinal anesthesia: a prospective, randomized, and controlled trial[J]. Int J Med Sci, 2022, 19(5): 909-915.
BEGEMANN K, NEUMANN A M, OSTER H. Regulation and function of extra-SCN circadian oscillators in the brain[J]. Acta Physiol (Oxf), 2020, 229(1): e13446.
LIU D Q, LI J Y, WU J Y, et al. Monochromatic blue light activates suprachiasmatic nucleus neuronal activity and promotes arousal in mice under sevoflurane anesthesia[J]. Front Neural Circuits, 2020, 14: 55.
MIZUNO T, HIGO S, KAMEI N, et al. Effects of general anesthesia on behavioral circadian rhythms and clock-gene expression in the suprachiasmatic nucleus in rats[J]. Histochem Cell Biol, 2022, 158(2): 149-158.
ZHU J, LU D, LIU J F. Intraoperative dexmedetomidine-related polyuria: a case report and review of the literature[J]. Int J Clin Pharmacol Ther, 2022, 60(4): 188-191.
RIVES J P, MILLET C, SCIARAFFA C, et al. Perioperative polyuria associated with dexmedetomidine administration during reconstruction breast surgery[J]. Anaesth Crit Care Pain Med, 2023, 42(5): 101290.
QIN C, LI J H, TANG K. The paraventricular nucleus of the hypothalamus: development, function, and human diseases[J]. Endocrinology, 2018, 159(9): 3458-3472.
YANG W Z, LI H, CHENG Z L, et al. Dex modulates the balance of water-electrolyte metabolism by depressing the expression of AVP in PVN[J]. Front Pharmacol, 2022, 13: 919032.
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
1
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
1
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
1
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
1
... 右美托咪定是一种选择性α2肾上腺素受体激动剂,通过作用于中枢神经系统和外周的α2受体产生相应的药理作用[1].1999年,右美托咪定被美国食品药品监督管理局(Food and Drug Administration,FDA)批准作为镇静剂用于重症监护室的患者管理;2009年被中国国家食品药品监督管理局批准用于气管插管和机械通气时的镇静[2].在过去的几年中右美托咪定在临床上的应用迅速扩大,已经在儿童镇静、口腔门诊患者镇静、局部镇痛的辅助、术后镇痛等领域展现出积极的作用.临床试验还发现右美托咪定可用于治疗慢性失眠[3],为其临床应用开辟了新的领域.基础研究方面则证实右美托咪定可以改善小鼠的抑郁样行为[4]、记忆障碍[5]和认知损伤[6],提示其可能具有更广泛的应用价值.因此,深入研究右美托咪定的作用机制对于发挥该药物的潜在价值并合理应用具有重要意义.本文就近年来右美托咪定在中枢神经的作用机制做一综述. ...
... 在哺乳动物的新生儿时期,发育中的大脑,尤其是海马的齿状回,要经历许多的神经发生、突触发生和连接,这些是学习和记忆的基础,在此期间,海马受到外部刺激,例如感染、氧化应激、毒素均可能导致广泛且通常不可逆的神经元损伤以及可塑性受损[75].在新生大鼠中使用高氧介导的脑损伤模型探究右美托咪定对齿状回神经发生的影响,发现暴露于高氧条件下显著降低了新生大鼠海马组织的增殖能力以及神经元标志物和转录因子的表达,神经可塑性调节因子也明显下降;然而,大鼠暴露在高氧前单次注射右美托咪定进行预处理,可以上调神经元分化、增殖、迁移和成熟[76].对于新生后的缺氧大鼠,右美托咪定治疗后,缺氧后认知功能损害减轻,受损突触恢复、突触后密度蛋白-95(postsynaptic density protein-95,PSD95)和突触素蛋白表达增加[77].由此可见,右美托咪定可以改善神经的可塑性,减轻其他不利影响导致的神经损伤. ...
1
... 在哺乳动物的新生儿时期,发育中的大脑,尤其是海马的齿状回,要经历许多的神经发生、突触发生和连接,这些是学习和记忆的基础,在此期间,海马受到外部刺激,例如感染、氧化应激、毒素均可能导致广泛且通常不可逆的神经元损伤以及可塑性受损[75].在新生大鼠中使用高氧介导的脑损伤模型探究右美托咪定对齿状回神经发生的影响,发现暴露于高氧条件下显著降低了新生大鼠海马组织的增殖能力以及神经元标志物和转录因子的表达,神经可塑性调节因子也明显下降;然而,大鼠暴露在高氧前单次注射右美托咪定进行预处理,可以上调神经元分化、增殖、迁移和成熟[76].对于新生后的缺氧大鼠,右美托咪定治疗后,缺氧后认知功能损害减轻,受损突触恢复、突触后密度蛋白-95(postsynaptic density protein-95,PSD95)和突触素蛋白表达增加[77].由此可见,右美托咪定可以改善神经的可塑性,减轻其他不利影响导致的神经损伤. ...
1
... 在哺乳动物的新生儿时期,发育中的大脑,尤其是海马的齿状回,要经历许多的神经发生、突触发生和连接,这些是学习和记忆的基础,在此期间,海马受到外部刺激,例如感染、氧化应激、毒素均可能导致广泛且通常不可逆的神经元损伤以及可塑性受损[75].在新生大鼠中使用高氧介导的脑损伤模型探究右美托咪定对齿状回神经发生的影响,发现暴露于高氧条件下显著降低了新生大鼠海马组织的增殖能力以及神经元标志物和转录因子的表达,神经可塑性调节因子也明显下降;然而,大鼠暴露在高氧前单次注射右美托咪定进行预处理,可以上调神经元分化、增殖、迁移和成熟[76].对于新生后的缺氧大鼠,右美托咪定治疗后,缺氧后认知功能损害减轻,受损突触恢复、突触后密度蛋白-95(postsynaptic density protein-95,PSD95)和突触素蛋白表达增加[77].由此可见,右美托咪定可以改善神经的可塑性,减轻其他不利影响导致的神经损伤. ...