Department of Pharmacology, University of Washington, Seattle, WA, USA.
Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA.
Nature. 2023 Jul;619(7969):332-337. doi: 10.1038/s41586-023-06246-7. Epub 2023 Jun 28.
Fast-acting neurotransmitters and slow, modulatory neuropeptides are co-released from neurons in the central nervous system, albeit from distinct synaptic vesicles. The mechanisms of how co-released neurotransmitters and neuropeptides that have opposing actions-for example, stimulatory versus inhibitory-work together to exert control of neural circuit output remain unclear. This has been difficult to resolve owing to the inability to selectively isolate these signalling pathways in a cell- and circuit-specific manner. Here we developed a genetic-based anatomical disconnect procedure that utilizes distinct DNA recombinases to independently facilitate CRISPR-Cas9 mutagenesis of neurotransmitter- and neuropeptide-related genes in distinct cell types in two different brain regions simultaneously. We demonstrate that neurons within the lateral hypothalamus that produce the stimulatory neuropeptide neurotensin and the inhibitory neurotransmitter GABA (γ-aminobutyric acid) utilize these signals to coordinately activate dopamine-producing neurons of the ventral tegmental area. We show that GABA release from lateral hypothalamus neurotensin neurons inhibits GABA neurons within the ventral tegmental area, disinhibiting dopamine neurons and causing a rapid rise in calcium, whereas neurotensin directly generates a slow inactivating calcium signal in dopamine neurons that is dependent on the expression of neurotensin receptor 1 (Ntsr1). We further show that these two signals work together to regulate dopamine neuron responses to maximize behavioural responding. Thus, a neurotransmitter and a neuropeptide with opposing signals can act on distinct timescales through different cell types to enhance circuit output and optimize behaviour.
快速作用的神经递质和缓慢的、调节性神经肽从中枢神经系统的神经元中共释放，尽管它们来自不同的突触小泡。共释放的具有相反作用的神经递质和神经肽（例如，刺激与抑制）如何协同作用以控制神经回路输出的机制仍不清楚。由于无法以细胞和回路特异性的方式选择性地分离这些信号通路，因此解决这个问题一直很困难。在这里，我们开发了一种基于遗传的解剖分离程序，该程序利用不同的 DNA 重组酶，同时在两个不同脑区的不同细胞类型中独立促进 CRISPR-Cas9 对神经递质和神经肽相关基因的突变。我们证明，产生兴奋性神经肽神经降压素和抑制性神经递质 GABA（γ-氨基丁酸）的外侧下丘脑神经元利用这些信号协调激活腹侧被盖区的多巴胺能神经元。我们表明，来自外侧下丘脑神经降压素神经元的 GABA 释放抑制腹侧被盖区中的 GABA 神经元，解除多巴胺神经元的抑制作用并导致钙的快速上升，而神经降压素直接在多巴胺神经元中产生依赖于神经降压素受体 1（Ntsr1）表达的缓慢失活钙信号。我们进一步表明，这两种信号协同作用以调节多巴胺神经元对行为反应的反应，从而最大化行为反应。因此，具有相反信号的神经递质和神经肽可以通过不同的细胞类型在不同的时间尺度上发挥作用，以增强回路输出并优化行为。
