Cerf-Ducastel Barbara, Murphy Claire
San Diego State University, San Diego, CA 92120-4913, USA.
Brain Res. 2003 Oct 3;986(1-2):39-53. doi: 10.1016/s0006-8993(03)03168-8.
Olfactory function is affected by aging and deficits often result in decreasing quality of life, health and safety. The present study investigated the cortical substrate of olfactory deficits related to aging with functional Magnetic Resonance Imaging (fMRI), with a retronasal olfactory stimulation protocol using flavored aqueous solutions presented to the mouth. Activation was found in young subjects in the piriform/amygdalar region and in the orbitofrontal cortex and in other areas previously found activated in neuroimaging studies using odorized air, including insula and cerebellum. Activation was seen in similar areas in old subjects but the degree of activation was significantly lower in regions receiving primary olfactory projections (piriform cortex, entorhinal cortex, and amygdala). This result supports the hypothesis of dysfunction and/or degeneration in areas critical to olfactory processing as a major cause of olfactory deficits in the older population.
嗅觉功能会受到衰老的影响，嗅觉减退常常导致生活质量、健康和安全水平下降。本研究采用功能磁共振成像（fMRI），通过向口腔呈现调味水溶液的鼻后嗅觉刺激方案，调查了与衰老相关的嗅觉减退的皮质基质。在年轻受试者中，梨状/杏仁核区域、眶额皮质以及先前在使用有气味空气的神经影像学研究中发现有激活的其他区域（包括岛叶和小脑）均有激活。老年受试者在类似区域也有激活，但在接受初级嗅觉投射的区域（梨状皮质、内嗅皮质和杏仁核）激活程度明显较低。这一结果支持了这样的假设，即对嗅觉处理至关重要的区域功能障碍和/或退化是老年人群嗅觉减退的主要原因。
