1. Prior stressor exposure delays the recovery of surgery-induced cognitive impairment and prolongs neuroinflammation in aged rats
- Author
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Lingwei Zhang, Hong Ma, Yaxuan Wang, Xuezhao Cao, Zhe Li, Wen-Fei Tan, and Yalei Gao
- Subjects
0301 basic medicine ,Male ,Aging ,medicine.medical_specialty ,medicine.medical_treatment ,Neuroscience(all) ,Interleukin-1beta ,Spatial Learning ,Clinical Neurology ,Hippocampus ,Hippocampal formation ,Rats, Sprague-Dawley ,03 medical and health sciences ,Inescapable tailshock (IS) ,0302 clinical medicine ,Postoperative Complications ,Neuroinflammation ,Antigens, CD ,Glial Fibrillary Acidic Protein ,medicine ,Memory impairment ,Animals ,Cognitive Dysfunction ,Glucocorticoids ,Molecular Biology ,Calcium metabolism ,Electroshock ,Interleukin-6 ,General Neuroscience ,Calcium-Binding Proteins ,Microfilament Proteins ,Interleukin ,Recovery of Function ,Prior stress ,Surgery ,Rats ,030104 developmental biology ,Cytokine ,Encephalitis ,Neurology (clinical) ,Cell activation ,Psychology ,030217 neurology & neurosurgery ,Stress, Psychological ,Postoperative cognitive dysfunction (POCD) ,Developmental Biology - Abstract
Increasing evidence indicates that stress potentiates pro-inflammatory response to a subsequent peripheral immune challenge. The present study investigated if prior exposure to inescapable tailshock (IS) delayed the recovery of surgery-induced spatial learning and memory impairment and prolonged hippocampus interleukin (IL)-1β and IL-6 expression. Methods A total of 192 aged rats were trained with Morris water-maze (MWM) for 6 consecutive days. A single session of inescapable tailshock was performed on day 6 after training. Then, the rats subjected to partial hepatectomy. Hippocampal-dependent spatial learning and memory were assessed on postoperative days 1, 3 and 7. The cytokines IL-1β and IL-6 and ionized calcium binding adaptor protein (Iba)-1 were measured at each time point. Cluster of differentiation 200 (CD200) was also measured to explore potential mechanisms of glial cell activation. Results Exposure of IS alone failed to affect the latency to platform and increase hippocampal cytokine levels at each time point. However, IS alone significantly increased the expression levels of Iba-1. A prolonged latency and additional significant increase in hippocampal levels of IL-1β and IL-6 were observed when partial hepatectomy was performed in aged rats exposed to IS 24 h later. The combination of IS and surgical trauma dramatically upregulated the levels of Iba-1 and significantly decreased the expression of CD200. Conclusion IS alone failed to induce cognitive deficits and increase pro-inflammatory cytokines expression. However, IS delayed the recovery of surgery-induced spatial learning and memory impairment and prolonged pro-inflammatory response to the subsequent surgery challenge.
- Published
- 2016
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