The olfactory tubercle (TUB), also called the tubular striatum, receives direct input from the olfactory bulb and, along with the nucleus accumbens, is one of the two principal components of the ventral striatum. As a key component of the reward system, the ventral striatum is involved in feeding behavior, but the vast majority of research on this structure has focused on the nucleus accumbens, leaving the TUB's role in feeding behavior understudied. Given the importance of olfaction in food seeking and consumption, olfactory input to the striatum should be an important contributor to motivated feeding behavior. Yet the TUB is vastly understudied in humans, with very little understanding of its structural organization and connectivity. In this study, we analyzed macrostructural variations between the TUB and the whole brain and explored the relationship between TUB structural pathways and feeding behavior, using body mass index (BMI) as a proxy in females and males. We identified a unique structural covariance between the TUB and the periaqueductal gray (PAG), which has recently been implicated in the suppression of feeding. We further show that the integrity of the white matter tract between the two regions is negatively correlated with BMI. Our findings highlight a potential role for the TUB–PAG pathway in the regulation of feeding behavior in humans.

嗅结节（TUB）也称为管状纹状体，接收来自嗅球的直接输入，与伏隔核一起是腹侧纹状体的两个主要组成部分之一。作为奖励系统的关键组成部分，腹侧纹状体参与摄食行为，但对该结构的绝大多数研究都集中在伏隔核上，而对 TUB 在摄食行为中的作用尚未得到充分研究。鉴于嗅觉在食物寻找和消费中的重要性，纹状体的嗅觉输入应该是动机性进食行为的重要贡献者。然而，人类对 TUB 的研究还很不足，对其结构组织和连接性知之甚少。在这项研究中，我们使用体重指数（BMI）作为女性和男性的代表，分析了 TUB 和全脑之间的宏观结构变化，并探讨了 TUB 结构通路与进食行为之间的关系。我们发现了 TUB 和导水管周围灰质 (PAG) 之间独特的结构协方差，最近与摄食抑制有关。我们进一步表明，两个区域之间白质束的完整性与 BMI 呈负相关。我们的研究结果强调了 TUB-PAG 通路在人类进食行为调节中的潜在作用。