The reduction of neuronal responses to repeated stimulus presentation occurs in many sensory neurons, also in the inferior colliculus of birds. The cellular mechanisms that cause response adaptation are not well described. Adaptation must be explicable by changes in the activity of input neurons, short-term synaptic plasticity of the incoming connections, excitability changes of the neuron under consideration or influences of inhibitory or modulatory network connections. Using whole-cell recordings in acute brain slices of the embryonic chicken brain we wanted to understand the intrinsic and synaptic contributions to adaptation in the core of the central nucleus of the inferior colliculus (ICCc). We described two neuron types in the chicken ICCc based on their action potential firing patterns: Phasic/onset neurons showed strong intrinsic adaptation but recovered more rapidly. Tonic/sustained firing neurons had weaker adaptation but often had additional slow components of recovery from adaptation. Morphological analysis suggested two neuron classes, but no physiological parameter aligned with this classification. Chicken ICCc neurons received mostly mixed AMPA- and NMDA-type glutamatergic synaptic inputs. In the majority of ICCc neurons the input synapses underwent short-term depression. With a simulation of the putative population output activity of the chicken ICCc we showed that the different adaptation profiles of the neuron classes could shift the emphasize of stimulus encoding from transients at long intervals to ongoing parts at short intervals. Thus, we report here that description of biophysical and synaptic properties can help to explain adaptive phenomena in central auditory neurons.

中文翻译：

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内在和突触动力学有助于适应下丘脑禽中央核的核心。

重复刺激呈现的神经元反应的减少在许多感觉神经元中也发生在鸟类的下丘。引起反应适应的细胞机制没有很好地描述。适应必须通过输入神经元活动的变化，传入连接的短期突触可塑性，所考虑的神经元的兴奋性变化或抑制性或调节性网络连接的影响来阐明。我们希望使用胚胎鸡脑的急性脑切片中的全细胞记录来了解下丘脑（ICCc）中央核的核心对适应的内在和突触贡献。我们根据鸡的ICCc动作电位触发模式描述了两种神经元类型：阶段性/发作性神经元显示出强大的内在适应能力，但恢复得更快。进补/持续激发神经元的适应性较弱，但通常具有从适应中恢复的其他缓慢成分。形态学分析建议两个神经元类，但没有生理参数与此分类相符。鸡ICCc神经元主要接受AMPA型和NMDA型谷氨酸能突触混合输入。在大多数ICCc神经元中，输入突触经历了短期抑郁。通过模拟鸡ICCc的假定种群输出活动，我们表明神经元类别的不同适应特征可以将刺激编码的重点从长间隔的瞬态转移到短间隔的持续部分。从而，