Department of Psychiatry, University of California, San Diego 9500 Gilman Drive, MC 0738 La Jolla, San Diego, CA 92093, USA.
Department of Neurosciences, University of California, La Jolla, San Diego, CA 92093, USA.
Viruses. 2021 Dec 10;13(12):2476. doi: 10.3390/v13122476.
Interoception, defined as the sense of the internal state of one's body, helps motivate goal-directed behavior. Prior work has shown that methamphetamine (METH) use disorder is associated with altered interoception, and that this may contribute to risky behavior. As people with HIV (PWH) may also experience disrupted bodily sensations (e.g., neuropathy), an important question is whether PWH with a history of METH use disorder might exhibit greater impairment of interoceptive processing.
Eighty-three participants stratified by HIV infection and a past history of methamphetamine use disorder experienced a soft touch paradigm that included slow brush strokes on the left forearm and palm during blood-oxygen level-dependent functional MRI acquisition. To assess differences in interoception and reward, voxelwise analyses were constrained to the insula, a hub for the evaluation of interoceptive cues, and the striatum, which is engaged in reward processing.
Overall, individuals with a history of METH use disorder had an attenuated neural response to pleasant touch in both the insula and striatum. Longer abstinence was associated with greater neural response to touch in the insula, suggesting some improvement in responsivity. However, only PWH with no METH use disorder history had lower brain activation in the insula relative to non-using seronegative controls.
Our findings suggest that while METH use disorder history and HIV infection independently disrupt the neural processes associated with interoception, PWH with METH use disorder histories do not show significant differences relative to non-using seronegative controls. These findings suggest that the effects of HIV infection and past methamphetamine use might not be additive with respect to interoceptive processing impairment.
内感受，即对自身身体内部状态的感知，有助于激发目标导向行为。先前的研究表明，甲基苯丙胺（METH）使用障碍与内感受改变有关，而这可能导致冒险行为。由于艾滋病毒（HIV）感染者（PWH）也可能经历身体感觉紊乱（例如，神经病），因此一个重要的问题是，是否有 METH 使用障碍史的 PWH 可能表现出更严重的内感受加工损伤。
83 名参与者根据 HIV 感染和过去的 METH 使用障碍史进行分层，在血氧水平依赖功能 MRI 采集期间经历了轻柔触摸范式，包括左前臂和手掌的缓慢刷动。为了评估内感受和奖励的差异，体素分析受到限制，只能在岛叶（评估内感受线索的枢纽）和纹状体（参与奖励处理）进行。
总体而言，有 METH 使用障碍史的个体在岛叶和纹状体对愉悦触摸的神经反应减弱。更长的禁欲时间与岛叶对触摸的神经反应增加有关，表明反应性有所改善。然而，只有没有 METH 使用障碍史的 PWH 相对于非使用的血清阴性对照，岛叶的大脑激活较低。
我们的发现表明，尽管 METH 使用障碍史和 HIV 感染独立地破坏了与内感受相关的神经过程，但有 METH 使用障碍史的 PWH 与非使用的血清阴性对照相比，并没有显示出显著的差异。这些发现表明，HIV 感染和过去使用 METH 的影响在对内感受加工损伤方面可能不是累加的。
