Cre recombinase mediated deletion of the NMDA receptor in dopamine neurons

Cre重组酶介导多巴胺神经元中NMDA受体的缺失

• 批准号: 7966949
• 负责人: Cristina Backman
• 金额: $ 41.74万
• 依托单位: NATIONAL INSTITUTE ON DRUG ABUSE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7966949
• 关键词: Agreement; Animals; Area; Bilateral; Brain; Cannulas; Cells; Chemosensitization; Cocaine; Data; Dopamine; Implant; Injection of therapeutic agent; Label; Laboratories; Lesion; Long-Term Potentiation; Mediating; Mediator of activation protein; Midbrain structure; Mus; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; NR1 gene; Neurons; Paper; Peripheral; Pharmaceutical Preparations; Population; Prefrontal Cortex; Publishing; Reporting; Role; Synapses; Synaptic plasticity; Treatment Protocols; behavioral sensitization; cocaine exposure; dopamine system; dopaminergic neuron; mRNA Expression; patch clamp; receptor; recombinase; research study; response

DAT-NR1 KO mice were implanted with a bilateral cannula in the VTA to deliver specific NMDAR antagonists during a cocaine sensitization regimen, and our results have shown that sensitization can be equally blocked in DAT-NR1 KO and WT animals by simultaneous injection of an NMDAR antagonist in the VTA along with peripheral cocaine. Our experiments are now aimed at ruling out or including the mesocortical DA cell population as the mediator of VTA NMDA dependent sensitization. We are currently performing patch-clamp recordings from retrograde labeled neurons projecting to the prefrontal cortex in DAT-NR1 KO to determine if these dopamine neurons, due to low DAT levels and therefore lack of Cre, may express NMDAR currents. In addition, TH-NR1 KO animals are being generated, and if viable, will be used to determine the response to cocaine sensitization, as in these KO animals NMDAR currents will be eliminated in all dopamine cells. Possible pitfalls when using TH-NR1 animals is the unspecificity of the NR1 deletion, as NMDAR will be deleted in all cathecholaminergic brain areas. However, if TH-NR1 KO animals do not develop cocaine induced sensitization it will suggest the likelihood of an active role of the DA mesocortical projection for the initiation of sensitization.

在可卡因致敏方案期间，在DAT-NR 1 KO小鼠的VTA中植入双侧插管以递送特异性NMDAR拮抗剂，并且我们的结果表明，通过在VTA中沿着外周可卡因同时注射NMDAR拮抗剂，可以同等地阻断DAT-NR 1 KO和WT动物的致敏作用。我们的实验现在旨在排除或包括中皮层DA细胞群作为VTA NMDA依赖性敏化的介质。我们目前正在进行膜片钳记录从逆行标记的神经元投射到前额叶皮层的DAT-NR 1 KO，以确定这些多巴胺神经元，由于低DAT水平，因此缺乏Cre，可能会表达NMDAR电流。此外，正在产生TH-NR 1 KO动物，如果存活，将用于确定对可卡因致敏的反应，因为在这些KO动物中，所有多巴胺细胞中的NMDAR电流将被消除。当使用TH-NR 1动物时，可能的陷阱是NR 1缺失的非特异性，因为NMDAR将在所有胆碱能脑区中缺失。然而，如果TH-NR 1 KO动物没有产生可卡因诱导的致敏作用，则表明DA中皮层投射可能在致敏作用的启动中发挥积极作用。