Moreno Amielle, Gumaste Ankita, Adams Geoff K, Chong Kelly K, Nguyen Michael, Shepard Kathryn N, Liu Robert C
Neuroscience Graduate Program, Emory University, 1462 Clifton Road, Atlanta, GA, 30322, USA; Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA, 30322, USA.
Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA, 30322, USA; Neuroscience and Behavior Biology Program, Emory University, 1462 Clifton Road, Atlanta, GA, 30322, USA.
Hear Res. 2018 Sep;366:38-49. doi: 10.1016/j.heares.2018.06.020. Epub 2018 Jun 28.
When a social sound category initially gains behavioral significance to an animal, plasticity events presumably enhance the ability to recognize that sound category in the future. In the context of learning natural social stimuli, neuromodulators such as norepinephrine and estrogen have been associated with experience-dependent plasticity and processing of newly salient social cues, yet continued plasticity once stimuli are familiar could disrupt the stability of sensorineural representations. Here we employed a maternal mouse model of natural sensory cortical plasticity for infant vocalizations to ask whether the engagement of the noradrenergic locus coeruleus (LC) by the playback of pup-calls is affected by either prior experience with the sounds or estrogen availability, using a well-studied cellular activity and plasticity marker, the immediate early gene c-Fos. We counted call-induced c-Fos immunoreactive (c-Fos-IR) cells in both LC and physiologically validated fields within the auditory cortex (AC) of estradiol or blank-implanted virgin female mice with either 0 or 5-days prior experience caring for vocalizing pups. Estradiol and pup experience interacted both in the induction of c-Fos-IR in the LC, as well as in behavioral measures of locomotion during playback, consistent with the neuromodulatory center's activity being an online reflection of both hormonal and experience-dependent influences on arousal. Throughout core AC, as well as in a high frequency sub-region of AC and in secondary AC, a main effect of pup experience was to reduce call-induced c-Fos-IR, irrespective of estradiol availability. This is consistent with the hypothesis that sound familiarity leads to less c-Fos-mediated plasticity, and less disrupted sensory representations of a meaningful call category. Taken together, our data support the view that any coupling between these sensory and neuromodulatory areas is situationally dependent, and their engagement depends differentially on both internal state factors like hormones and external state factors like prior experience.
当一个社会声音类别最初对动物获得行为意义时，可塑性事件大概会增强其未来识别该声音类别的能力。在学习自然社会刺激的背景下，去甲肾上腺素和雌激素等神经调质与经验依赖性可塑性以及新突显的社会线索的处理有关，但一旦刺激变得熟悉，持续的可塑性可能会破坏感觉神经表征的稳定性。在这里，我们采用了一种针对幼崽叫声的自然感觉皮质可塑性的母鼠模型，以探讨通过播放幼崽叫声激活去甲肾上腺素能蓝斑核（LC）是否受声音的先前经验或雌激素水平的影响，我们使用了一种经过充分研究的细胞活性和可塑性标记物——即早基因c-Fos。我们在雌二醇或空白植入的未孕雌性小鼠的LC以及听觉皮层（AC）内经过生理学验证的区域中，对有或没有5天照料发声幼崽先前经验的小鼠，计数叫声诱导的c-Fos免疫反应性（c-Fos-IR）细胞。雌二醇和幼崽经验在LC中c-Fos-IR的诱导以及播放期间运动行为测量方面存在相互作用，这与神经调节中心的活动是激素和经验依赖性唤醒影响的在线反映一致。在整个AC核心区域，以及在AC的高频子区域和次级AC中，幼崽经验的主要作用是减少叫声诱导的c-Fos-IR，而与雌二醇水平无关。这与声音熟悉度导致较少的c-Fos介导的可塑性以及较少破坏有意义叫声类别的感觉表征这一假设一致。综上所述，我们的数据支持这样一种观点，即这些感觉和神经调节区域之间的任何耦合都取决于具体情况，它们的参与分别取决于内部状态因素如激素和外部状态因素如先前经验。
