77
个编辑
更改
跳到导航
跳到搜索
第29行：
第29行： − + − + − + − Power law distributions of sequence sizes have also been observed in spikes from the isolated [[leech ganglion]] (V. Torre, conference talk) and in spikes from [[dissociated cortical cultures]] (L. Bettencourt; R. Alessio, personal communications), suggesting that the phenomenon of avalanches may be quite general to in-vitro preparations. Preliminary reports also indicate that avalanches are present in the superficial cortical layers of awake, resting primates (Petermann et al, 2006). These reports have not been published yet and are included here only to indicate that researchers are now exploring the avalanche concept in a variety of preparations.+ + + +
→Generality
[[沙堆模型|临界沙堆模型]]中的雪崩在其形成的模式中是随机的，与之相比，[[局部场电位]]的雪崩发生的时空模式比预期的偶然性更频繁（Beggs和Plenz，2004）。图中显示了一个急性皮层切片的几个这样的模式。这些模式在长达10个小时的时间内是可重复的，其时间精度为4ms（Beggs和Plenz，2004）。这些模式的稳定性和精确性表明，神经雪崩可以被[[神经网络]]用作存储信息的基底。在这个意义上，雪崩似乎与在动物执行认知任务时在体内观察到的动作电位序列相似。目前还不清楚体内数据的重复活动模式是否也是雪崩。
[[沙堆模型|临界沙堆模型]]中的雪崩在其形成的模式中是随机的，与之相比，[[局部场电位]]的雪崩发生的时空模式比预期的偶然性更频繁（Beggs和Plenz，2004）。图中显示了一个急性皮层切片的几个这样的模式。这些模式在长达10个小时的时间内是可重复的，其时间精度为4ms（Beggs和Plenz，2004）。这些模式的稳定性和精确性表明，神经雪崩可以被[[神经网络]]用作存储信息的基底。在这个意义上，雪崩似乎与在动物执行认知任务时在体内观察到的动作电位序列相似。目前还不清楚体内数据的重复活动模式是否也是雪崩。
===Generality===
===普遍性===
In the above example, avalanches are produced in cortical slice cultures bathed in culture medium, but it is also possible to produce avalanches in acute [[cortical slices]] when they are bathed in [[artificial cerebrospinal fluid]] with [[dopamine]] agonists and [[NMDA]] <!-- confirm NMDA; do you mean glutamate or do you mean NMDA receptors? Yes, I mean NMDA. -JB.--> (Beggs and Plenz, 2003; Stewart and Plenz, 2006), or with high K<sup>+</sup> and low Mg<sup>++</sup>. The different ways of inducing avalanches suggests that they are not particular to only one set of experimental conditions.
In the above example, avalanches are produced in cortical slice cultures bathed in culture medium, but it is also possible to produce avalanches in acute [[cortical slices]] when they are bathed in [[artificial cerebrospinal fluid]] with [[dopamine]] agonists and [[NMDA]] <!-- confirm NMDA; do you mean glutamate or do you mean NMDA receptors? Yes, I mean NMDA. -JB.--> (Beggs and Plenz, 2003; Stewart and Plenz, 2006), or with high K<sup>+</sup> and low Mg<sup>2+</sup>. The different ways of inducing avalanches suggests that they are not particular to only one set of experimental conditions.
====Preliminary Reports in Other Systems====
在上述示例中，雪崩是在浸泡在培养基中的皮层切片培养中产生的，但当急性皮层切片在含有[https://en.wikipedia.org/wiki/Dopamine 多巴胺]激动剂和[https://en.wikipedia.org/wiki/N-Methyl-D-aspartic_acid NMDA]（Beggs和Plenz，2003；Stewart和Plenz，2006）或高K<sup>+</sup>和低Mg<sup>2+</sup>的人工[https://en.wikipedia.org/wiki/Cerebrospinal_fluid 脑脊液]中浸泡时，也可能在急性皮层切片中产生雪崩。诱发雪崩的不同方式表明，它们不仅仅局限于一组实验条件。
====其他系统中的初步报告====
在离体水蛭神经节（V.Torre，conference talk）的棘波和分离皮层培养的棘波（L.Bettencourt；R.Alessio，personal communications）中也观察到序列大小的幂律分布，这表明雪崩现象可能在体外制剂中相当普遍。初步报告还表明，在清醒和休息的灵长类动物的表层皮层中存在雪崩（Petermann等人，2006年）。这些报告尚未发表，在此仅表明研究人员目前正在探索各种制剂中的雪崩概念。
==雪崩模型 Models of avalanches==
==雪崩模型 Models of avalanches==