Bistability with Hysteresis in the Activity of Vasopressin Cells
Bistability with Hysteresis in the Activity of Vasopressin Cells
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加压素细胞活性的双稳定性和滞后性
DOI：
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发表时间：
2007
影响因子：
3.2
通讯作者：
G. Leng
中科院分区：
文献类型：
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作者：
N. Sabatier;G. Leng
大细胞加压素神经元产生独特的“阶段性”电活动模式，在此期间，尖峰活动（爆发）与无尖峰或偶尔尖峰的时期交替。体内爆发终止的机制仍然不清楚。我们在体内记录了单相加压素细胞，在这里我们表明，在一些相细胞中的爆发终止之前是活性的短暂增加，与作为活性依赖性抑制的结果而结束的爆发一致。我们表明，extraditionally强加的活动增加，引起短暂刺激的终板的血管器，可以触发突发，如果给定的时候，一个细胞是沉默的，或停止突发，如果给定的时候，一个细胞是活跃的。因此，大细胞血管加压素系统是一个独立的单振荡器群体。人口作为一个整体是不敏感的瞬态变化输入电平，无论这些是兴奋性或抑制性。因此，加压素细胞群的作用就像一个“低通滤波器”;虽然输入速率的短暂大变化对整体影响不大，但通过进化出一种有效维持分泌的放电活动模式，细胞群对输入速率的小而持续的变化反应非常有效。我们注意到，这些滤波特性与通常与神经元相关的滤波特性相反。
Magnocellular vasopressin neurones generate distinctive ‘phasic’ patterns of electrical activity during which periods of spiking activity (bursts) alternate with periods of no spikes or occasional spikes. The mechanisms of burst termination in vivo are still not clearly understood. We recorded from single phasic vasopressin cells in vivo and here we show that burst terminations in some phasic cells is preceded by transient increases in activity, consistent with bursts ending as a result of activity‐dependent inhibition. We show that extrinsically imposed increases in activity, evoked by brief stimulation of the organum vasculosum of the lamina terminalis, can either trigger bursts if given when a cell is silent, or stop bursts if given when a cell is active. Thus, the magnocellular vasopressin system is a population of independent bistable oscillators. The population as a whole is insensitive to transient changes in input level, whether these are excitatory or inhibitory. The vasopressin cell population thus acts like a ‘low‐pass filter’; although brief large changes in input rate have little overall effect, the population responds very effectively to small, sustained changes in input rate by evolving a pattern of discharge activity that efficiently maintains secretion. We note that these filtering characteristics are the opposite of the filtering characteristics that are typically associated with neurones.