CLP290 promotes the sedative effects of midazolam in neonatal rats in a KCC2-dependent manner: A laboratory study in rats

Molecular Signaling Effects behind the Spontaneous Soleus Muscle Activity Induced by 7-Day Rat Hindlimb Suspension

The elimination of ground reaction force (support withdrawal) vastly affects slow postural muscles in terms of their regulation and structure. One of the effects of support withdrawal in this study was an immediate postural muscle inactivation, followed by the daily gradual development of spontaneous activity of the slow postural soleus muscle in response to rat hindlimb suspension to mimic space flight. The origin of this activity is somewhat akin to muscle spasticity after spinal cord injuries and is the result of KCC2 content decline in the spinal cord's motor neurons. However, the physiological consequences of unloading-induced spontaneous activity remain unexplored. We have conducted an experiment with the administration of a highly specific KCC2 activator during 7-day unloading. For this experiment, 32 male Wistar rats were divided into 4 groups: C+placebo, C+CLP-290 (100 mg/kg b w), 7HS+placebo, and 7HS+CLP-hindlimb-suspended group with CLP-290 administration (100 mg/kg b w). The soleus muscles of the animals were dissected and analyzed for several proteostasis- and metabolism-related parameters. CLP-290 administration to the unloaded animals led to the upregulation of AMPK downstream (p-ACC) and mTOR targets (p-p70S6k and p-4E-BP) and an enhanced PGC1alpha decrease vs. the 7HS group, but neither prevented nor enhanced atrophy of the soleus muscle or myofiber CSA.

Effects of Midazolam on Antioxidant Levels, Biochemical and Metabolic Parameters in Eurygaster integriceps Puton (Hemiptera: Scutelleridae) Eggs Parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae)

Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is among the most important insect pests of wheat (Triticum sativum L.) and barley (Hordeum vulgare L.) grown in the Middle East. Biological and chemical methods are insufficient to control E. integriceps populations below economic thresholds. In this study, we investigated the effects of midazolam, a clinical drug, on selected metabolic enzyme activity, antioxidant levels, and biochemical parameters in E. integriceps eggs parasitized by Trissolcus semistriatus Nees (Hymenoptera: Scelionidae). Increasing concentrations of midazolam caused cell damage in the parasitized eggs due to its oxidative effects. Transferase enzymes, such as, aspartate transferase, alanine transferase, and gamma glutamyl transferase activities were altered following exposure. Metabolic enzymes, such as, creatine kinase, alkaline phosphatase, amylase, and lactate dehydrogenase also were adversely affected. Levels of the non-enzymatic antioxidants uric acid, bilirubin, and albumin also were altered.

Sevoflurane-based enhancement of phase-amplitude coupling and localization of the epileptogenic zone

OBJECTIVE

Phase-amplitude coupling between high-frequency (≥150 Hz) and delta (3-4 Hz) oscillations - modulation index (MI) - is a promising, objective biomarker of epileptogenicity. We determined whether sevoflurane anesthesia preferentially enhances this metric within the epileptogenic zone.

METHODS

This is an observational study of intraoperative electrocorticography data from 621 electrodes chronically implanted into eight patients with drug-resistant, focal epilepsy. All patients were anesthetized with sevoflurane during resective surgery, which subsequently resulted in seizure control. We classified 'removed' and 'retained' brain sites as epileptogenic and non-epileptogenic, respectively. Mixed model analysis determined which anesthetic stage optimized MI-based classification of epileptogenic sites.

RESULTS

MI increased as a function of anesthetic stage, ranging from baseline (i.e., oxygen alone) to 2.0 minimum alveolar concentration (MAC) of sevoflurane, preferentially at sites showing higher initial MI values. This phenomenon was accentuated just prior to sevoflurane reaching 2.0 MAC, at which time, the odds of a site being classified as epileptogenic were enhanced by 86.6 times for every increase of 1.0 MI.

CONCLUSIONS

Intraoperative MI best localized the epileptogenic zone immediately before sevoflurane reaching 2.0 MAC in this small cohort of patients.

SIGNIFICANCE

Prospective, large cohort studies are warranted to determine whether sevoflurane anesthesia can reduce the need for extraoperative, invasive evaluation.