Behavioral Profiling of Zebrafish (Danio rerio) Larvae: Activity, Anxiety, Avoidance, and Startle Response

Apart from morphological, biochemical, and genetic alterations induced by teratogen compounds, there is an increased interest in characterizing behavioral alterations. Behavior is a sensitive parameter that can provide information regarding developmental disruptions non-invasively. Behavioral disturbances interfere with animals' capacity to cope with the environment, having an impact on the organism's life. Hereby, behavioral assays consisting of recording larvae in multi-well plates, Petri dishes, or cuvettes and video analysis using adequate software, allowing teratogen screening of behavior, are proposed. Examples of how to evaluate locomotor, anxiety-like and avoidance-like behaviors, and the integrity of sensory-motor functions and learning are discussed in this chapter.

Anesthesia and Cognitive Outcome in Elderly Patients: A Narrative Viewpoint

Better ways to manage preoperative, intraoperative and postoperative care of surgical patients is the bailiwick of anesthesiologists. Although we care for patients of all ages, protecting the cognitive capacity of elderly patients more frequently requires procedures and practices that go beyond routine care for nonelderly adults. This narrative review will consider current understanding of the reasons that elderly patients need enhanced care, and recommendations for that care based on established and recent empirical research. In that latter regard, unless and until we are able to classify anesthetic neurotoxicity as a rare complication, the first-do-no-harm approach should: (1) add anesthesia to surgical intervention on the physiological cost side of the cost/benefit ratio when making decisions about whether and when to proceed with surgery; (2) minimize anesthetic depth and periods of electroencephalographic suppression; (3) limit the duration of continuous anesthesia whenever possible; (4) consider the possibility that regional anesthesia with deep sedation may be as neurotoxic as general anesthesia; and (5) when feasible, use regional anesthesia with light or no sedation.

Lithium chloride ameliorates cognition dysfunction induced by sevoflurane anesthesia in rats

Postoperative cognitive dysfunction is a common complication in elderly patients after surgeries involving anesthesia, but the underlying mechanisms are poorly understood. Lithium is a conventional treatment for bipolar disorder, which exerts a neuroprotective role in various diseases by inhibiting glycogen synthase kinase‐3β (GSK‐3β) in the brain and spinal cord. However, it is not known whether lithium chloride (LiCl) can protect against cognitive dysfunction induced by sevoflurane (SEV) anesthesia. Here, we examined the effects of LiCl on SEV‐induced cognitive dysfunction in rats and on SEV‐induced neuron apoptosis. We report that anesthesia with SEV significantly impaired memory performance, induced oxidative stress and hippocampal neuron apoptosis, and stimulated GSK‐3β activity. Treatment with LiCl ameliorated SEV‐induced cognitive disorder in rats by inhibiting the GSK‐3β/β‐catenin signaling pathway. In addition, LiCl reduced hippocampal neuron apoptosis and oxidative stress induced by SEV anesthesia. These results suggest that LiCl may have potential for development into a therapeutic agent for treatment of SEV anesthesia‐induced cognitive dysfunction.

Review on the use of zebrafish embryos to study the effects of anesthetics during early development

Over the years, the potential toxicity of anesthetics has raised serious concerns about its safe use during pregnancy. As evidence emerged from research in animal models, showing that some anesthetic drugs are potential teratogenic, the determination of the risk of exposures to anesthetic drugs at early life stages became mandatory. However, due to inaccessibility and ethical constrains related to experimental conditions, the use of early life stages in mammalian models is limited. In this regard, some animal and nonanimal models have been suggested to surpass mammalian use in experimentation. Among them, the zebrafish embryo test has been recognized as a promising alternative in toxicology research, as well as an inexpensive and practical test. Substantial information collected from developmental research following compounds exposure, has contributed to the application of zebrafish assays in research, although only a few studies have focused on the use of early life stages of zebrafish to evaluate the developmental effects of anesthetics. Based on the recent advances of science and technology, there is a clear potential for zebrafish early life stages to provide new insights into anesthetics teratogenicity. This review provides an overview of recent anesthesia research using zebrafish embryos, demonstrating its usefulness to the anesthesia field, discussing the recent findings on various aspects related to the effects of anesthetics during early life development and the strengths and limitations of this model system.

Behavioral Profiling of Zebrafish (Danio rerio) Larvae Following Teratogen Exposure

Apart from morphological, biochemical, and genetic alterations induced by teratogen compounds, there is an increase interest in characterizing behavioral alterations. Behavior is a sensitive parameter that can provide information regarding developmental disruptions noninvasively, as it is the result of brain processes. Behavioral disturbances interfere with animals' capacity to cope with the environment, having an impact on the organism's life. Hereby, it is proposed behavioral assays consisting on recording larvae in multiwell plates and video analysis with a proper software, allowing for teratogen screening of behavior. How to evaluate locomotor, anxiety-like and avoidance-like behaviors, and the integrity of sensory-motor functions and learning are discussed in this chapter.

Longitudinal Dynamics of 3-Dimensional Components of Selfhood After Severe Traumatic Brain Injury: A qEEG Case Study

In this report, we describe the case of a patient who sustained extremely severe traumatic brain damage with diffuse axonal injury in a traffic accident and whose recovery was monitored during 6 years. Specifically, we were interested in the recovery dynamics of 3-dimensional components of selfhood (a 3-dimensional construct model for the complex experiential selfhood has been recently proposed based on the empirical findings on the functional-topographical specialization of 3 operational modules of brain functional network responsible for the self-consciousness processing) derived from the electroencephalographic (EEG) signal. The analysis revealed progressive (though not monotonous) restoration of EEG functional connectivity of 3 modules of brain functional network responsible for the self-consciousness processing, which was also paralleled by the clinically significant functional recovery. We propose that restoration of normal integrity of the operational modules of the self-referential brain network may underlie the positive dynamics of 3 aspects of selfhood and provide a neurobiological mechanism for their recovery. The results are discussed in the context of recent experimental studies that support this inference. Studies of ongoing recovery after severe brain injury utilizing knowledge about each separate aspect of complex selfhood will likely help to develop more efficient and targeted rehabilitation programs for patients with brain trauma.

Early childhood exposure to short periods of sevoflurane is not associated with later, lasting cognitive deficits

BACKGROUND

A detrimental effect of commonly used anesthetics on the neurodevelopmental and behavioral parameters has long been shown in young animals subjected to early childhood anesthesia. Epidemiologic studies suggest the possibility of a modestly elevated risk of adverse neurodevelopmental outcomes in children exposed to anesthesia during early childhood. However, these results are still preliminary and inconclusive.

AIM

To further elucidate the probability of occurrence of such adverse outcomes, we evaluated cognitive performance of children who underwent general anesthesia early in their childhood.

METHOD

One hundred and fifteen children aged 5-16 years with established glaucoma were included in the study. Of these, 68 children had a history of at least one general anesthesia with sevoflurane before age 3. Phonemic and semantic verbal fluency, and forward and backward digit span tests were performed to evaluate cognitive function in the study subjects.

RESULTS

The two-way anova revealed that all these variables showed significant changes in various age groups, but they were comparable among subjects with no, single, or multiple childhood anesthesia.

CONCLUSION

It can be concluded that brief periods of anesthesia with single anesthetic sevoflurane may be safe for children under age 3.

Comparison of the type and severity of early attentional network decline after total intravenous or epidural anesthesia in middle-aged women after gynecological surgery

Compared with regional anesthesia, general anesthesia may increase the risk of postoperative cognitive decline. This study aimed to investigate the type and severity of attentional network decline and the recovery of attentional networks in middle-aged women after gynecological surgery. A total of 140 consenting women undergoing elective gynecological surgery were enrolled in the study. Patients were assigned randomly to receive either total intravenous anesthesia or epidural anesthesia. To determine the efficacy of the attentional networks, patients were examined for alerting, orienting, and executive networks on the preoperative day and on the first and fifth postoperative days using the attentional network test. Significant differences were observed in the effect scores of the three attentional networks at all time points. These effect scores differed significantly between groups and between 1 and 5 days postoperation (DPO). Participants showed significantly lower effect scores for the alerting and orienting network tasks and had more difficulties in resolving conflict at 1 DPO compared with the baseline. On comparing effect scores between baseline and 5 DPO, no significant differences on the alerting and orienting network tasks were observed in the epidural anesthesia group, a significant difference on the orienting network task was observed in the general anesthesia group, and significant differences on the executive control network were observed in both the groups. Compared with epidural anesthesia, total intravenous anesthesia is more likely to impair and delay the recovery of attentional networks in middle-aged women undergoing elective hysterectomy. The executive control function showed marked damage and there were difficulties in recovery from either type of anesthesia.

Postoperative cognitive dysfunction in older adults: a call for nursing involvement

As the population continues to age and new medical developments make surgery at advanced ages increasingly possible, it is important to consider how older adults tolerate surgery and anesthesia. Considerable evidence shows that older adults have a higher risk of developing postoperative cognitive dysfunction (POCD), which leads to transient and sometimes long-term cognitive changes that may affect quality of life. Because little is known about how to prevent or treat POCD, it is important that nurses identify ways in which they can intervene to help patients who experience this disorder.

Pediatric anesthesia and neurodevelopmental impairments: a Bayesian meta-analysis

Experimental evidence of anesthesia-induced neurotoxicity has caused serious concern about the long-term effect of commonly used volatile anesthetic agents on young children. Several observational studies based on existing data have been conducted to address this concern with inconsistent results. We conducted a meta-analysis to synthesize the epidemiologic evidence on the association of anesthesia/surgery with neurodevelopmental outcomes in children. Using Bayesian meta-analytic approaches, we estimated the synthesized odds ratios (OR) and 95% credible interval (CrI) as well as the predictive distribution of a future study given the synthesized evidence. Data on 7 unadjusted and 6 adjusted measures of association were abstracted from 7 studies. The synthesized OR based on the 7 unadjusted measures for the association of anesthesia/surgery with an adverse behavioral or developmental outcome was 1.9 (95% CrI, 1.2-3.0). The most likely unadjusted OR from a future study was estimated to be 2.2 (95% CrI, 0.6-6.1). The synthesized OR based on the 6 adjusted measures for the association of anesthesia/surgery with an adverse behavioral or developmental outcome was 1.4 (95% CrI, 0.9-2.2). The most likely adjusted OR from a future study was estimated to be 1.5 (95% CrI, 0.5-4.0). We conclude that existent epidemiologic evidence suggests a modestly elevated risk of adverse behavioral or developmental outcomes in children who were exposed to anesthesia/surgery during early childhood. The evidence, however, is considerably uncertain.