Testosterone Treatment Mimics Seasonal Downregulation of Dopamine Innervation in the Auditory System of Female Midshipman Fish
Testosterone Treatment Mimics Seasonal Downregulation of Dopamine Innervation in the Auditory System of Female Midshipman Fish
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睾酮治疗模拟雌性见习鱼听觉系统多巴胺神经支配的季节性下调
DOI：
10.1093/icb/icab070
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发表时间：
2021
影响因子：
2.6
通讯作者：
Forlano, Paul M
中科院分区：
文献类型：
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作者：
Perelmuter, Jonathan T;Hom, Kelsey N;Mohr, Robert A;Demis, Lina;Kim, Spencer;Chernenko, Alena;Timothy, Miky;Middleton, Mollie A;Sisneros, Joseph A;Forlano, Paul M
在季节性繁殖的脊椎动物中，激素协调神经系统结构和功能的变化，以促进生殖准备和成功。类固醇激素通常通过调节神经调质间接发挥其作用，神经调质反过来又可以协调感觉输入与适当运动输出的调节。雌性平鳍见习鱼（Porichthys notatus）在夏季繁殖季节及时进行外周听觉灵敏度的提高，提高了它们检测配偶的能力，这是由类固醇激素调节的。生殖女性也表现出不同的听觉回路的儿茶酚胺神经支配相比，冬季，非生殖女性酪氨酸羟化酶（TH），在儿茶酚胺合成的限速酶测定。重要的是，从多巴胺能特异性前脑核到内耳的儿茶酚胺能输入在夏季减少，多巴胺抑制内耳的敏感性，这表明性腺类固醇可能通过调节多巴胺神经支配来改变听觉敏感性。在这项研究中，我们gonadectomized非生殖女性，植入他们与雌二醇（E2）或睾酮（T），并测量TH免疫反应（TH-IR）纤维在听觉核中的儿茶酚胺神经支配以前被证明是季节性的塑料。我们发现，治疗与T，而不是E2，减少TH-IR神经支配的听觉后脑。T-治疗还减少了前脑多巴胺能细胞群中投射到内耳和可能投射到听觉后脑的TH-ir纤维。治疗组血浆T升高与内耳TH阳性终末减少相关。这些T-治疗诱导的TH-IR纤维的变化模仿的季节性下调多巴胺在海军军官学校的内耳，并提供证据表明，类固醇激素调节外周听觉灵敏度介导的，在一定程度上，多巴胺。
In seasonally breeding vertebrates, hormones coordinate changes in nervous system structure and function to facilitate reproductive readiness and success. Steroid hormones often exert their effects indirectly via regulation of neuromodulators, which in turn can coordinate the modulation of sensory input with appropriate motor output. Female plainfin midshipman fish (Porichthys notatus) undergo increased peripheral auditory sensitivity in time for the summer breeding season, improving their ability to detect mates, which is regulated by steroid hormones. Reproductive females also show differences in catecholaminergic innervation of auditory circuitry compared with winter, non-reproductive females as measured by tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholaminergic synthesis. Importantly, catecholaminergic input to the inner ear from a dopaminergic-specific forebrain nucleus is decreased in the summer and dopamine inhibits the sensitivity of the inner ear, suggesting that gonadal steroids may alter auditory sensitivity by regulating dopamine innervation. In this study, we gonadectomized non-reproductive females, implanted them with estradiol (E2) or testosterone (T), and measured TH immunoreactive (TH-ir) fibers in auditory nuclei where catecholaminergic innervation was previously shown to be seasonally plastic. We found that treatment with T, but not E2, reduced TH-ir innervation in the auditory hindbrain. T-treatment also reduced TH-ir fibers in the forebrain dopaminergic cell group that projects to the inner ear, and likely to the auditory hindbrain. Higher T plasma in the treatment group was correlated with reduced-ir TH terminals in the inner ear. These T-treatment induced changes in TH-ir fibers mimic the seasonal downregulation of dopamine in the midshipman inner ear and provide evidence that steroid hormone regulation of peripheral auditory sensitivity is mediated, in part, by dopamine.