Physical, chemical, and functional properties of neuronal membranes vary between species of Antarctic notothenioids differing in thermal tolerance.
Physical, chemical, and functional properties of neuronal membranes vary between species of Antarctic notothenioids differing in thermal tolerance.
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DOI：
10.1007/s00360-019-01207-x
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发表时间：
2019-04
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影响因子：
--
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中科院分区：
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神经元功能的破坏可能会影响热耐受性的极限。我们假设急性变暖神经元膜的结构和功能在南极notothenioid鱼Chaenocephalus aceratus更容易受到扰动比膜更耐热的notothenioid Notothenia coriiceps。对两种南极鱼类大脑的突触膜、线粒体膜和髓磷脂的流动性进行了量化。分析髓磷脂极性脂质组成和胆固醇含量；在突触膜中测量胆固醇。研究人员测定了两种膜相关蛋白乙酰胆碱酯酶（AChE）和Na+/K+- atp酶（NKA）的活性，这些蛋白来自于处于环境温度或暴露于临界热最大值（CTMAX）的动物大脑。针叶树的突触膜始终比粗叶树的突触膜更具流动性（P<0.0001）。尽管不同种属的髓磷脂和线粒体膜的流动性相似，但髓磷脂流动性对体外升温的敏感性在科里塞贝中高于在针叶树（P<0.001），这可能与科里塞贝髓磷脂中胆固醇含量较低有关（P<0.05）。在CTMAX的作用下，针叶树中AChE和NKA酶的活性均下降，而在山毛杨中则没有下降。我们认为，在变暖的情况下，棘鱼的突触膜的超流化可能解释了该物种更大的狭窄性，并且与神经系统的其他膜相比，棘鱼的热极限更可能受到突触膜扰动的影响。
Disruption of neuronal function is likely to influence limits to thermal tolerance. We hypothesized that with acute warming the structure and function of neuronal membranes in the Antarctic notothenioid fish Chaenocephalus aceratus are more vulnerable to perturbation than membranes in the more thermotolerant notothenioid Notothenia coriiceps. Fluidity was quantified in synaptic membranes, mitochondrial membranes, and myelin from brains of both species of Antarctic fishes. Polar lipid compositions and cholesterol contents were analyzed in myelin; cholesterol was measured in synaptic membranes. Thermal profiles were determined for activities of two membrane-associated proteins, acetylcholinesterase (AChE) and Na+/K+-ATPase (NKA), from brains of animals maintained at ambient temperature or exposed to their critical thermal maxima (CTMAX). Synaptic membranes of C. aceratus were consistently more fluid than those of N. coriiceps (P<0.0001). Although the fluidities of both myelin and mitochondrial membranes were similar among species, sensitivity of myelin fluidity to in vitro warming was greater in N. coriiceps than in C. aceratus (P<0.001), which can be explained by lower cholesterol contents in myelin of N. coriiceps (P<0.05). Activities of both enzymes, AChE and NKA, declined upon CTMAX exposure in C. aceratus, but not in N. coriiceps. We suggest that hyper-fluidization of synaptic membranes with warming in C. aceratus may explain the greater stenothermy in this species, and that thermal limits in notothenioids are more likely to be influenced by perturbations in synaptic membranes than in other membranes of the nervous system.
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DOI：
10.1007/bf00612674
发表时间：
1976-01-01
期刊：
JOURNAL OF COMPARATIVE PHYSIOLOGY
影响因子：
--
作者：
FRIEDLANDER, MJ;KOTCHABHAKDI, N;PROSSER, CL
通讯作者：
PROSSER, CL
影响因子：
1.6
作者：
Devor, Devin P.;Kuhn, Donald E.;Crockett, Elizabeth L.
通讯作者：
Crockett, Elizabeth L.
影响因子：
14.8
作者：
Dunkley, Peter R.;Jarvie, Paula E.;Robinson, Phillip J.
通讯作者：
Robinson, Phillip J.
影响因子：
2.8
作者：
Grim, J. M.;Miles, D. R. B.;Crockett, E. L.
通讯作者：
Crockett, E. L.
DOI：
10.1016/0005-2736(77)90131-6
发表时间：
1977-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
COSSINS, AR
通讯作者：
COSSINS, AR