Happer Joseph P, Courtney Kelly E, Baca Rachel E, Andrade Gianna, Thompson Courtney, Shen Qian, Liu Thomas T, Jacobus Joanna
Department of Psychiatry, University of California, San Diego, San Diego, CA, United States.
Department of Neurosciences, University of California, San Diego, San Diego, CA, United States.
Front Neurosci. 2024 Aug 16;18:1436951. doi: 10.3389/fnins.2024.1436951. eCollection 2024.
With the advent of electronic nicotine delivery systems, the use of nicotine and tobacco products (NTPs) among adolescents and young adults remains high in the US. Use of e-cigarettes additionally elevates the risk of problematic use of other substances like cannabis, which is often co-used with NTPs. However, their effects on brain health, particularly the hippocampus, and cognition during this neurodevelopmental period are poorly understood.
Healthy late adolescents/young adults ( = 223) ages 16-22 completed a structural MRI to examine right and left hippocampal volumes. Memory was assessed with the NIH Toolbox Picture Sequence Memory Test (PSMT) and Rey Auditory Verbal Learning Test (RAVLT). Cumulative 6-month NTP and cannabis episodes were assessed and modeled continuously on hippocampal volumes. Participants were then grouped based on 6-month NTP use to examine relationships with the hippocampus and memory: current users (CU) endorsed weekly or greater use; light/abstinent users (LU) endorsed less than weekly; and never users (NU).
NTP use predicted larger hippocampal volumes bilaterally while cannabis use had no impact nor interacted with NTP use. For memory, larger left hippocampal volumes were positively associated with PSMT performance, RAVLT total learning, short delay and long delay recall for the NU group. In contrast, there was a negative relationship between hippocampal volumes and performances for LU and CU groups. No differences were detected between NTP-using groups.
These results suggest that the hippocampus is sensitive to NTP exposure during late adolescence/young adulthood and may alter typical hippocampal morphometry in addition to brain-behavior relationships underlying learning and memory processes.
随着电子尼古丁输送系统的出现，美国青少年和年轻成年人中尼古丁和烟草制品（NTPs）的使用率仍然很高。使用电子烟还会增加使用大麻等其他物质出现问题的风险，大麻经常与NTPs共同使用。然而，人们对它们在这个神经发育阶段对大脑健康，特别是海马体以及认知的影响知之甚少。
16至22岁的健康青少年晚期/年轻成年人（n = 223）完成了一次结构磁共振成像（MRI），以检查左右海马体体积。使用美国国立卫生研究院（NIH）工具箱图片序列记忆测试（PSMT）和雷伊听觉词语学习测试（RAVLT）评估记忆力。评估了6个月内NTP和大麻使用的累计次数，并以海马体体积为连续变量进行建模。然后根据6个月内NTP的使用情况将参与者分组，以研究与海马体和记忆力的关系：当前使用者（CU）认可每周或更频繁的使用；轻度/不使用者（LU）认可少于每周的使用；从不使用者（NU）。
使用NTPs预测双侧海马体体积更大，而使用大麻既无影响，也不与NTPs的使用相互作用。对于记忆力，较大的左侧海马体体积与NU组的PSMT表现、RAVLT总学习量、短期延迟和长期延迟回忆呈正相关。相比之下，LU组和CU组的海马体体积与表现之间存在负相关。在使用NTPs的组之间未检测到差异。
这些结果表明，海马体在青少年晚期/年轻成年期对NTP暴露敏感，除了学习和记忆过程背后的脑-行为关系外，还可能改变典型的海马体形态测量。
