Department of Physiology, The Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
Faculty of Veterinary Medicine, Department of Veterinary Medicine Islamic Azad University of Kazeroon, Shiraz, Iran.
PLoS One. 2024 May 15;19(5):e0302850. doi: 10.1371/journal.pone.0302850. eCollection 2024.
Vascular dementia (VD) is a common type of dementia. This study aimed to evaluate the effects of low and high doses of lutein administration in bilateral-carotid vessel occlusion (2VO) rats.
The rats were divided into the following groups: the control, sham-, vehicle (2VO+V) groups, and two groups after 2VO were treated with lutein 0.5 (2VO+LUT-o.5) and 5mg/kg (2VO+LUT-5). The passive-avoidance and Morris water maze were performed to examine fear and spatial memory. The field-potential recording was used to investigate the properties of basal synaptic transmission (BST), paired-pulse ratio (PPR), as an index for measurement of neurotransmitter release, and long-term potentiation (LTP). The hippocampus was removed to evaluate hippocampal cells, volume, and MDA level.
Treatment with low and high doses improves spatial memory and LTP impairment in VD rats, but only the high dose restores the fear memory, hippocampal cell loss, and volume and MDA level. Interestingly, low-dose, but not high-dose, increased PPR. However, BST recovered only in the high-dose treated group.
Treatment with a low dose might affect neurotransmitter release probability, but a high dose affects postsynaptic processes. It seems likely that low and high doses improve memory and LTP through different mechanisms.
血管性痴呆（VD）是一种常见的痴呆症类型。本研究旨在评估叶黄素低、高剂量给药对双侧颈总动脉闭塞（2VO）大鼠的影响。
将大鼠分为以下几组：对照组、假手术组、载体组（2VO+V）以及 2VO 后用叶黄素 0.5mg/kg（2VO+LUT-o.5）和 5mg/kg（2VO+LUT-5）处理的两组。通过被动回避和 Morris 水迷宫实验评估恐惧和空间记忆。使用场电位记录评估基础突触传递（BST）、成对脉冲比（PPR），作为测量神经递质释放的指标，以及长时程增强（LTP）。取出海马评估海马细胞、体积和 MDA 水平。
低、高剂量治疗均可改善 VD 大鼠的空间记忆和 LTP 损伤，但只有高剂量恢复了恐惧记忆、海马细胞丢失、体积和 MDA 水平。有趣的是，低剂量而非高剂量增加了 PPR。然而，仅在高剂量治疗组中恢复了 BST。
低剂量治疗可能影响神经递质释放概率，但高剂量治疗影响突触后过程。低、高剂量可能通过不同的机制改善记忆和 LTP。
