Plastic and stable electrophysiological properties of adult avian forebrain song-control neurons across changing breeding conditions.
Plastic and stable electrophysiological properties of adult avian forebrain song-control neurons across changing breeding conditions.
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DOI：
10.1523/jneurosci.5571-08.2009
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发表时间：
2009-05-20
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影响因子：
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通讯作者：
Perkel DJ
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文献类型：
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作者：
Meitzen J;Weaver AL;Brenowitz EA;Perkel DJ
类固醇性激素驱动许多动物分类群的神经系统和行为变化，但将前者与后者整合仍然具有挑战性。应对这一挑战的一个有用的模式系统是季节性繁殖鸣禽。在这些物种中，血浆睾酮水平随季节而上升和下降，改变了歌曲行为，并导致歌曲控制系统（一组控制歌曲行为的离散核团）的急剧增长和退化。虽然核体积变化的细胞机制已被研究作为神经生长和退化的模型，但尚不清楚这些神经结构的变化是否伴随着自发放电率以外的电生理特性的变化。在这里，我们测试的假设，被动和主动的前脑歌曲控制核HVC和RA的神经元特性的变化在整个育种条件。我们将成年雄性甘氏白冠麻雀暴露于短日照或长日照光周期和系统性睾酮，分别模拟非繁殖和繁殖条件。我们在急性脑切片中从RA和HVC神经元进行了全细胞记录。我们发现：RA投射神经元的膜时间常数，电容，诱发和自发放电率都增加在繁殖条件下，测量的HVC中间神经元和投射神经元的电生理特性是稳定的整个繁殖条件。这种可塑性和稳定的内在特性的结合可能会直接影响歌曲控制系统在不同季节的运动控制，从而导致歌曲刻板性的变化。这些结果为整合类固醇激素如何调节细胞生理学以改变行为提供了一个有价值的框架。
Steroid sex hormones drive changes in the nervous system and behavior in many animal taxa, but integrating the former with the latter remains challenging. One useful model system for meeting this challenge is seasonally breeding songbirds. In these species, plasma testosterone levels rise and fall across the seasons, altering song behavior and causing dramatic growth and regression of the song-control system, a discrete set of nuclei that control song behavior. While the cellular mechanisms underlying changes in nucleus volume have been studied as a model for neural growth and degeneration, it is unknown whether these changes in neural structure are accompanied by changes in electrophysiological properties other than spontaneous firing rate. Here we test the hypothesis that passive and active neuronal properties in the forebrain song-control nuclei HVC and RA change across breeding conditions. We exposed adult male Gambel’s white-crowned sparrows to either short-day photoperiod or long-day photoperiod and systemic testosterone to simulate nonbreeding and breeding condition, respectively. We made whole cell recordings from RA and HVC neurons in acute brain slices. We found that: RA projection neuron membrane time constant, capacitance, and evoked and spontaneous firing rate were all increased in breeding condition; the measured electrophysiological properties of HVC interneurons and projection neurons were stable across breeding conditions. This combination of plastic and stable intrinsic properties could directly impact the song-control system’s motor control across seasons, underlying changes in song stereotypy. These results provide a valuable framework for integrating how steroid hormones modulate cellular physiology to change behavior.