Department of Neuroscience and Cognition, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Golgasht Street, East Azarbayjan, Tabriz, Iran.
Department of Physiology, Faculty of Medicine, Tabriz University of Medical Sciences, Golgasht Street, East Azarbayjan, 51666-14766, Tabriz, Iran.
Exp Brain Res. 2023 Jun;241(6):1569-1583. doi: 10.1007/s00221-023-06577-x. Epub 2023 May 2.
Although the disruptive effects of spinal cord injury (SCI) on the hippocampus have been confirmed in some animal studies, no study has investigated its retrograde manifestations in the hippocampus of aged subjects. Herein, we compared the aged rats with young ones 3 weeks after the induction of SCI (Groups: Sham.Young, SCI.Young, Sham.Aged, SCI.Aged). The locomotion, hippocampal apoptosis, hippocampal rhythms (Delta, Theta, Beta, Gamma) max frequency (Max.rf) and power, hippocampal neurogenesis, and hippocampal receptors (NMDA, GABA A, Muscarinic1/M1), which are important in the generation of rhythms and neurogenesis, were compared in aged rats in contrast to young rats. At the end of the third week, the number of apoptotic (Tunel) cells in the hippocampus (CA1, DG) of SCI animals was significantly higher compared to the sham animals, and also, it was significantly higher in the SCI.Aged group compared to SCI.Young group. Moreover, the rate of neurogenesis (DCX, BrdU cells) and expression of M1 and NMDA receptors were significantly lower in the SCI.Aged group compared to SCI.Young group. The power and Max.fr of all rhythms were significantly lower in SCI groups compared to sham groups. Despite the decrease in the power of rhythms in the SCI.Aged group compared to SCI.Young group, there was no significant difference between them, and in terms of Max.fr index, only the Max.fr of theta and beta rhythms were significantly lower in the SCI.Aged group compared to SCI.Young group. This study showed that SCI could cause more neurodegeneration in the hippocampus of aged animals compared to young animals.
尽管一些动物研究已经证实了脊髓损伤（SCI）对海马体的破坏作用，但没有研究调查过其在老年动物海马体中的逆行表现。在此，我们比较了 SCI 诱导后 3 周的老年大鼠和年轻大鼠（组：假手术年轻组、SCI 年轻组、假手术老年组、SCI 老年组）。比较了老年大鼠与年轻大鼠之间的运动、海马体凋亡、海马体节律（Delta、Theta、Beta、Gamma）最大频率（Max.rf）和功率、海马体神经发生以及在节律和神经发生中起重要作用的海马体受体（NMDA、GABA A、毒蕈碱 1/M1）。在第 3 周结束时，与假手术动物相比，SCI 动物的海马体（CA1、DG）中的凋亡（Tunel）细胞数量显著增加，并且 SCI 老年组比 SCI 年轻组显著增加。此外，与 SCI 年轻组相比，SCI 老年组的神经发生率（DCX、BrdU 细胞）和 M1 和 NMDA 受体的表达显著降低。与假手术组相比，SCI 组的所有节律的功率和 Max.fr 均显著降低。尽管与 SCI 年轻组相比，SCI 老年组的节律功率降低，但两组之间没有显著差异，而且就 Max.fr 指数而言，只有 theta 和 beta 节律的 Max.fr 在 SCI 老年组中显著低于 SCI 年轻组。本研究表明，与年轻动物相比，SCI 可导致老年动物海马体中更多的神经退行性变。
