Ouda Ladislav, Druga Rastislav, Syka Josef
Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
Exp Gerontol. 2008 Aug;43(8):782-9. doi: 10.1016/j.exger.2008.04.001. Epub 2008 Apr 6.
Changes in the levels of calcium binding proteins are known to occur in different parts of the brain during aging. In our study we attempted to define the effect that aging has on the parvalbumin-expressing system of neurons in the higher parts of the central auditory system. Age-related changes in parvalbumin immunoreactivity were investigated in the inferior colliculus (IC), medial geniculate body (MGB) and auditory cortex (AC) in two rat strains, normally aging Long-Evans (LE) and fast aging Fischer 344 (F344). The results demonstrate that the changes in PV-immunoreactivity are strain-dependent with an increase in the number of PV-immunoreactive (PV-ir) neurons occurring in the inferior colliculus of old LE rats and a pronounced decline in the number of PV-ir neurons appearing in the auditory cortex of aged F344 animals. In some parts of the AC of old F344 animals no PV-ir neurons were present at all. The number of PV-ir neurons in the MGB in all examined animals was very low independent of the strain and age. The loss of PV-ir neurons in the auditory cortex of Fischer 344 rats with aging may contribute to the substantial deterioration of hearing function in this strain.
已知在衰老过程中，大脑不同部位会出现钙结合蛋白水平的变化。在我们的研究中，我们试图确定衰老对中枢听觉系统较高部位中表达小白蛋白的神经元系统的影响。在两种大鼠品系中，即正常衰老的长 Evans 大鼠（LE）和快速衰老的 Fischer 344 大鼠（F344），研究了下丘（IC）、内侧膝状体（MGB）和听觉皮层（AC）中小白蛋白免疫反应性的年龄相关变化。结果表明，小白蛋白免疫反应性的变化具有品系依赖性，老年 LE 大鼠下丘中表达小白蛋白免疫反应性（PV-ir）的神经元数量增加，而老年 F344 动物听觉皮层中 PV-ir 神经元数量则显著减少。在老年 F344 动物听觉皮层的某些部位，根本不存在 PV-ir 神经元。所有检查动物的 MGB 中 PV-ir 神经元数量都非常少，与品系和年龄无关。Fischer 344 大鼠听觉皮层中 PV-ir 神经元随年龄增长而丢失，可能导致该品系听力功能的严重衰退。
