加拿大麦吉尔大学Rosemary C. Bagot团队发现，性别偏倚的神经编码在伏隔核传入纤维中驱动威胁辨别以抑制奖励行为。这一研究成果于2024年9月5日在线发表在国际学术期刊《自然—神经科学》上。

通过记录在厌恶性和中性提示期间的两个伏隔核（NAc）谷氨酸能传入纤维的神经活动，研究人员揭示了威胁提示辨别中的性别偏倚编码。在雄性小鼠中，来自腹侧海马的NAc传入纤维对威胁提示有优先激活。

在雌性小鼠中，这些腹侧海马-NAc投射纤维对威胁和非威胁提示都被激活，而来自内侧前额皮质的NAc传入纤维则更多地被脚电击激活，并能可靠地区分威胁与非威胁。

化学遗传学特定通路抑制研究发现，尽管具有类似的突触连接，腹侧海马-NAc和内侧前额皮质-NAc投射在提示介导的奖励动机行为抑制中表现出双重分离。研究人员认为这些性别偏倚可能反映了行为策略上的性别差异，这可能对理解性别在精神疾病风险中的差异具有重要意义。

据介绍，学习预测威胁是至关重要的，但同样重要（尽管常常被忽视）的是学习威胁的缺失。

附：英文原文

Title: Sex-biased neural encoding of threat discrimination in nucleus accumbens afferents drives suppression of reward behavior

Author: Muir, Jessie, Iyer, Eshaan S., Tse, Yiu-Chung, Sorensen, Julian, Wu, Serena, Eid, Rand S., Cvetkovska, Vedrana, Wassef, Karen, Gostlin, Sarah, Vitaro, Peter, Spencer, Nick J., Bagot, Rosemary C.

Issue&Volume: 2024-09-05

Abstract: Learning to predict threat is essential, but equally important—yet often overlooked—is learning about the absence of threat. Here, by recording neural activity in two nucleus accumbens (NAc) glutamatergic afferents during aversive and neutral cues, we reveal sex-biased encoding of threat cue discrimination. In male mice, NAc afferents from the ventral hippocampus are preferentially activated by threat cues. In female mice, these ventral hippocampus–NAc projections are activated by both threat and nonthreat cues, whereas NAc afferents from medial prefrontal cortex are more strongly recruited by footshock and reliably discriminate threat from nonthreat. Chemogenetic pathway-specific inhibition identifies a double dissociation between ventral hippocampus–NAc and medial prefrontal cortex–NAc projections in cue-mediated suppression of reward-motivated behavior in male and female mice, despite similar synaptic connectivity. We suggest that these sex biases may reflect sex differences in behavioral strategies that may have relevance for understanding sex differences in risk of psychiatric disorders.

DOI: 10.1038/s41593-024-01748-7

Source: https://www.nature.com/articles/s41593-024-01748-7