Anesthetics fragment hippocampal network activity, alter spine dynamics, and affect memory consolidation.
Yang Wei,Chini Mattia,Pöpplau Jastyn A,Formozov Andrey,Dieter Alexander,Piechocinski Patrick,Rais Cynthia,Morellini Fabio,Sporns Olaf,Hanganu-Opatz Ileana L,Wiegert J Simon
General anesthesia is characterized by reversible loss of consciousness accompanied by transient amnesia. Yet, long-term memory impairment is an undesirable side effect. How different types of general anesthetics (GAs) affect the hippocampus, a brain region central to memory formation and consolidation, is poorly understood. Using extracellular recordings, chronic 2-photon imaging, and behavioral analysis, we monitor the effects of isoflurane (Iso), medetomidine/midazolam/fentanyl (MMF), and ketamine/xylazine (Keta/Xyl) on network activity and structural spine dynamics in the hippocampal CA1 area of adult mice. GAs robustly reduced spiking activity, decorrelated cellular ensembles, albeit with distinct activity signatures, and altered spine dynamics. CA1 network activity under all 3 anesthetics was different to natural sleep. Iso anesthesia most closely resembled unperturbed activity during wakefulness and sleep, and network alterations recovered more readily than with Keta/Xyl and MMF. Correspondingly, memory consolidation was impaired after exposure to Keta/Xyl and MMF, but not Iso. Thus, different anesthetics distinctly alter hippocampal network dynamics, synaptic connectivity, and memory consolidation, with implications for GA strategy appraisal in animal research and clinical settings.
Volatile anesthetics versus intravenous anesthetics for noncardiac thoracic surgery: a systematic review and meta-analysis.
Fan Yuchao,Yu Deshui,Liang Xiao
INTRODUCTION:We performed this meta-analysis of randomized controlled trials (RCTs) to investigate two types of anesthetics for noncardiac thoracic surgery regarding their effects on clinical outcomes and the inflammatory response. EVIDENCE ACQUISITION:We searched Cochrane Library, PubMed and Embase for RCTs comparing volatile anesthetics to intravenous anesthetics for noncardiac thoracic surgery. EVIDENCE SYNTHESIS:This study reviewed 16 RCTs with 1467 patients. Volatile anesthetics reduced postoperative complications and the length of intensive care unit stay for lung surgery. They also lowered the concentrations of interleukin (IL)-1β, IL-6, IL-8 and tumour necrosis factor-α (TNF-α) in the airways of patients undergoing noncardiac thoracic surgery. However, there was no difference in short-term mortality, postoperative complications after esophagectomy, IL-1β, IL-6, IL-8 or TNF-α concentrations in the blood, IL-10 level in either the airway or the blood, overall monocyte chemoattractant protein-1. CONCLUSIONS:In lung surgery, but not esophagectomy, volatile anesthetics may be a better choice than intravenous anesthetics, possibly because volatile anesthetics reduce airway inflammation.