Relationship between locus coeruleus discharge rates and rates of norepinephrine release within neocortex as assessed by in vivo microdialysis
Relationship between locus coeruleus discharge rates and rates of norepinephrine release within neocortex as assessed by in vivo microdialysis
复制标题
DOI：
10.1016/s0306-4522(99)00276-6
复制
发表时间：
1999-01-01
期刊：
影响因子：
3.3
通讯作者：
Abercrombie, ED
中科院分区：
文献类型：
--
作者：
Berridge, CW;Abercrombie, ED
在麻醉大鼠上观察了蓝斑去甲肾上腺素能神经元放电率与去甲肾上腺素释放率之间的关系。蓝斑神经元的神经元放电率的改变和量化使用组合记录输液探头。蓝斑周围注入胆碱能激动剂氨甲酰胆碱或α 2-激动剂可乐定，分别用于增强或抑制神经元放电活动。使用体内微透析和高压液相色谱电化学检测法测定前额叶皮质内细胞外去甲肾上腺素浓度的变化。在蓝斑放电活动的完全抑制和基础放电水平的约300-400%（1.58 +/- 0.29 Hz）之间观察到蓝斑活动和去甲肾上腺素透析液浓度之间的线性关系。高于这些水平，蓝斑放电率的增加并不伴随着透析液去甲肾上腺素浓度的类似增加。在一般情况下，无论是激活或抑制蓝斑神经元放电率出现改变放电活动和去甲肾上腺素流出在随后的时期之间的关系。一个例外，这是在恢复期间观察到相对高幅度的蓝斑激活。在蓝斑放电率增加超过450%的三个病例中，有两个病例去甲肾上腺素浓度恢复到基础水平的速度比蓝斑神经元放电率恢复到基础水平的速度更快，虽然有限，但后一种观察结果表明，在蓝斑以最高速率持续激活后，可能会发生去甲肾上腺素释放的失调，这可能会模仿那些与强烈的唤醒或压力有关的症状。(C)1999年IBRO。爱思唯尔科技有限公司出版
The relationship between discharge rates of locus coeruleus noradrenergic neurons and rates of norepinephrine release was examined in the anesthetized rat. Neuronal discharge rates of locus coeruleus neurons were altered and quantified using a combined recording-infusion probe. Peri-locus coeruleus infusions of either the cholinergic agonist, bethanechol, or the alpha(2)-agonist, clonidine, were used to enhance or suppress neuronal discharge activity, respectively. Alterations in concentrations of extracellular norepinephrine within the prefrontal cortex were determined using in vivo microdialysis and high-pressure liquid chromatography with electrochemical detection. A linear relationship between locus coeruleus activity and norepinephrine dialysate concentration was observed between complete suppression of locus coeruleus discharge activity and approximately 300-400% of basal discharge levels (1.58 +/- 0.29 Hz). Above these levels, increases in locus coeruleus discharge rates were not accompanied by similar increases in dialysate norepinephrine concentrations. In general, neither activation nor suppression of locus coeruleus neuronal discharge rates appeared to alter the relationship between discharge activity and norepinephrine efflux during subsequent epochs. The one exception to this was observed during recovery from relatively high-magnitude locus coeruleus activation. In two out of three cases in which locus coeruleus discharge rates were increased greater than 450%, a recovery of norepinephrine concentrations to basal levels occurred more quickly than the recovery of locus coeruleus neuronal discharge rates to basal levels.Although limited, these latter observations suggest that dysregulation of norepinephrine release may occur following sustained activation of locus coeruleus at the highest rates examined, which may mimic those associated with intense arousal or stress. (C) 1999 IBRO. Published by Elsevier Science Ltd.