Synaptic inhibition: its role in suprachiasmatic nucleus neuronal thermosensitivity and temperature compensation in the rat.
Synaptic inhibition: its role in suprachiasmatic nucleus neuronal thermosensitivity and temperature compensation in the rat.
复制标题
突触抑制：其在大鼠视交叉上核神经元热敏感性和温度补偿中的作用。
DOI：
10.1111/j.1469-7793.1998.793bd.x
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Boulant,JA
中科院分区：
文献类型：
--
作者：
Burgoon,PW;Boulant,JA
1分析了大鼠脑切片中视交叉上核（SCN）神经元的全细胞膜片钳记录，以了解温度变化期间自发突触活动的变化。虽然最近的研究已经确定了一些SCN神经元中的温度敏感性反应，但尚不清楚热信息是否或如何通过SCN神经网络进行通信，特别是因为SCN等生物钟被认为是温度补偿的。自发抑制性突触后电位（IPSPs）和电流（IPSCs）常被10-50 μ m的甲基碘化荷包牡丹碱（BMI）阻断。BMI用于验证抑制性突触能够增强或抑制SCN神经元的温度敏感性的假设。3温度对IPSP和IPSC的幅度具有相反的影响。加温降低IPSP振幅，但增加IPSC振幅。这表明，热诱导的IPSP振幅的变化主要是由突触后膜的电阻变化的影响。温度对IPSP幅值的影响有助于增强某些神经元的温度敏感性。4在许多SCN神经元中，温度影响IPSP和IPSC的频率。IPSP频率随温度升高而增加，冷却过程中频率降低，使几个SCN神经元对温度不敏感，使这些神经元在温度变化期间保持相对恒定的放电率。突触频率的这种温度调节变化提供了大鼠SCN的温度补偿机制。
1Whole‐cell patch clamp recordings of neurones in the suprachiasmatic nucleus (SCN) from rat brain slices were analysed for changes in spontaneous synaptic activity during changes in temperature. While recent studies have identified temperature‐sensitive responses in some SCN neurones, it is not known whether or how thermal information can be communicated through SCN neural networks, particularly since biological clocks such as the SCN are assumed to be temperature compensated.2Synaptic activity was predominantly inhibitory and mediated through GABAAreceptor activation. Spontaneous inhibitory postsynaptic potentials (IPSPs) and currents (IPSCs) were usually blocked with perifusion of 10–50 μmbicuculline methiodide (BMI). BMI was used to test hypotheses that inhibitory synapses are capable of either enhancing or suppressing the thermosensitivity of SCN neurones.3Temperature had opposite effects on the amplitude of IPSPs and IPSCs. Warming decreased IPSP amplitude but increased IPSC amplitude. This suggests that thermally induced changes in IPSP amplitude are primarily influenced by resistance changes in the postsynaptic membrane. The thermal effect on IPSP amplitude contributed to an enhancement of thermosensitivity in some neurones.4In many SCN neurones, temperature affected the frequency of IPSPs and IPSCs. An increase in IPSP frequency with warming and a decrease in frequency during cooling made several SCN neurones temperature insensitive, allowing these neurones to maintain a relatively constant firing rate during changes in temperature. This temperature‐adjusted change in synaptic frequency provides a mechanism of temperature compensation in the rat SCN.