Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China.
Shenzhen Key Lab of Neuropsychiatric Modulation and Collaborative Innovation Center for Brain Science, Guangdong Provincial Key Laboratory of Brain Connectome and Behavior, CAS Center for Excellence in Brain Science and Intelligence Technology, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen, 518055, China; McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Neurosci Lett. 2020 Jul 27;732:135059. doi: 10.1016/j.neulet.2020.135059. Epub 2020 May 23.
The dorsal periacqueductal gray (dPAG) is a midbrain structure having an essential role in coordinating defensive behaviors in response to aversive stimulation. However, the question of whether dPAG neurons can respond to aversive conditioning and retrieval, properties involved in emergence of negative emotional state, is still under debate. Here we used calcium imaging by fiber photometry to record the activity of dPAG and dPAG neuronal populations during unconditioned and conditioned aversive stimulation. Then, following an unconditioned stimulation we performed a retrieval experiment to quantify memory-like responses of dPAG neurons. This shown that whilst both dPAG and dPAG neuronal populations respond to direct US stimulation, and to CS stimulation during conditioning, only the dPAG population persisted in responding to the CS stimulation during retrieval. Finally to better understand these divergences in dPAG and dPAG responses, we investigated their respective connectivity patterns by performing a cell specific monosynaptic retrograde rabies virus tracing experiment. This revealed that different patterns of fibers projects to dPAG and dPAG, which could explain part of their response specificities. This may indicate that glutamatergic subpopulation is a main contributor of aversive memories in dPAG.
背侧导水管周围灰质（dorsal periaqueductal gray，dPAG）是中脑的一个结构，在协调对厌恶刺激的防御行为方面起着至关重要的作用。然而，关于 dPAG 神经元是否能对厌恶条件反射和检索做出反应，即涉及负面情绪状态出现的特性，这仍然存在争议。在这里，我们使用光纤光度法钙成像来记录未条件刺激和条件刺激期间 dPAG 和 dPAG 神经元群体的活动。然后，在未条件刺激后，我们进行了检索实验，以量化 dPAG 神经元的记忆样反应。结果表明，虽然 dPAG 和 dPAG 神经元群体都对直接 US 刺激以及条件刺激期间的 CS 刺激做出反应，但只有 dPAG 群体在检索期间持续对 CS 刺激做出反应。最后，为了更好地理解 dPAG 和 dPAG 反应之间的这些差异，我们通过进行特定细胞的单突触逆行狂犬病毒追踪实验来研究它们各自的连接模式。这表明不同的纤维投射模式投射到 dPAG 和 dPAG，这可以解释它们部分反应特异性的原因。这可能表明谷氨酸能亚群是 dPAG 中厌恶记忆的主要贡献者。
