Department of Biology, Gettysburg College, Gettysburg, PA 17325, United States.
Department of Biology, Gettysburg College, Gettysburg, PA 17325, United States.
Physiol Behav. 2023 May 1;263:114131. doi: 10.1016/j.physbeh.2023.114131. Epub 2023 Feb 14.
Across vertebrates, the midbrain periaqueductal gray (PAG) plays a critical role in social and vocal behavior. Dopaminergic neurotransmission also modulates these behaviors, and dopaminergic innervation of the PAG has been well documented. Nonetheless, the potential role of dopamine in shaping vocal production at the level of the PAG is not well understood. Here, we tested the hypothesis that dopamine modulates vocal production in the PAG, using a well-characterized vertebrate model system for the study of vocal communication, the plainfin midshipman fish, Porichthys notatus. We found that focal dopamine injections to the midshipman PAG rapidly and reversibly inhibited vocal production triggered by stimulation of known vocal-motor structures in the preoptic area / anterior hypothalamus. While dopamine inhibited vocal-motor output, it did not alter behaviorally-relevant parameters of this output, such as vocalization duration and frequency. Dopamine-induced inhibition of vocal production was prevented by the combined blockade of D1- and D2-like receptors but was unaffected by isolated blockade of either D1-receptors or D2-receptors. Our results suggest dopamine neuromodulation in the midshipman PAG may inhibit natural vocal behavior, in courtship and/or agonistic social contexts.
在脊椎动物中，中脑导水管周围灰质（PAG）在社交和发声行为中起着关键作用。多巴胺能神经传递也调节这些行为，并且 PAG 的多巴胺能神经支配已经得到充分证实。尽管如此，多巴胺在塑造 PAG 水平上的发声产生方面的潜在作用仍未得到很好的理解。在这里，我们使用已被充分证实的用于研究发声交流的脊椎动物模型系统——普通鲷鱼，Porichthys notatus，检验了多巴胺调节 PAG 发声产生的假设。我们发现，向鲷鱼 PAG 注射焦点多巴胺可快速且可逆地抑制由前脑区/下丘脑前区中已知的发声运动结构刺激引发的发声产生。虽然多巴胺抑制发声运动输出，但它不会改变这种输出的与行为相关的参数，例如发声持续时间和频率。D1- 和 D2-样受体的联合阻断可防止多巴胺诱导的发声抑制，但 D1-受体或 D2-受体的单独阻断对其无影响。我们的结果表明，鲷鱼 PAG 中的多巴胺神经调节可能会抑制求爱和/或竞争社会环境中的自然发声行为。
