Wireless EEG Recording of Audiogenic Seizure Activity in Freely Moving Krushinsky-Molodkina Rats.

This study investigates audiogenic epilepsy in Krushinsky-Molodkina (KM) rats, questioning the efficacy of conventional EEG techniques in capturing seizures during animal restraint. Using a wireless EEG system that allows unrestricted movement, our aim was to gather ecologically valid data. Nine male KM rats, prone to audiogenic seizures, received implants of wireless EEG transmitters that target specific seizure-related brain regions. These regions included the inferior colliculus (IC), pontine reticular nucleus, oral part (PnO), ventrolateral periaqueductal gray (VLPAG), dorsal area of the secondary auditory cortex (AuD), and motor cortex (M1), facilitating seizure observation without movement constraints. Our findings indicate that targeted neural intervention via electrode implantation significantly reduced convulsive seizures in approximately half of the subjects, suggesting therapeutic potential. Furthermore, the amplitude of brain activity in the IC, PnO, and AuD upon audiogenic stimulus onset significantly influenced seizure severity and nature, highlighting these areas as pivotal for epileptic propagation. Severe cases exhibited dual waves of seizure generalization, indicative of intricate neural network interactions. Distinctive interplay between specific brain regions, disrupted during convulsive activity, suggests neural circuit reconfiguration in response to escalating seizure intensity. These discoveries challenge conventional methodologies, opening avenues for novel approaches in epilepsy research and therapeutic interventions.

Early-life maternal deprivation in rats increases sensitivity to the subsequent stressors: a pilot study.

Early life experiences, particularly maternal deprivation (MD), have long-lasting implications on emotional and cognitive development. Using Wistar rats as a model, this study explores the impact of MD followed by predator stress exposure (PSS) to simulate aspects of post-traumatic stress disorder (PTSD). A cohort of 41 male rat pups underwent MD from postnatal days 2 to 14, followed by PSS at day 90. Female rat pups were not included in the experiment. Behavior was subsequently assessed using the Elevated Plus Maze test 14 days post-PSS. While MD led to subtle changes such as decreased activity and increased anxiety-like behavior, PSS induced pronounced anxiogenic effects. Notably, PSS after MD resulted in decreased basal corticosterone levels, mirroring conditions observed in PTSD. The findings suggest that although MD itself does not induce significant behavioral changes, it predisposes individuals to heightened sensitivity to subsequent stressors. This study underscores the utility of a two-stage PSS model for more accurately reflecting the complexities inherent in stress-related disorders, including PTSD.

Stem cells and cardiac arrhythmias.

Recent discoveries in the physiology and pathology of myocardial progenitor cells have allowed researchers to better understand a variety of cardiac pathologies and look at the pathophysiology of arrhythmias from a different perspective. Since the myocardium is composed of a syncytium of electrically interconnected cells, the process of incorporation of newly formed or imported cells into its structure is particularly important. Progenitor cells are stimulated by spontaneous electrical activity, a lengthy action potential, and easily induced triggering activity. All these can lead to arrhythmias development via the three classical mechanisms (reentrancy, automatism, or triggering activity). Transplanted stem cells can influence the electrophysiological properties of cardiomyocytes, thus creating a proarrhythmic substrate. The islets of unbound cells can form an anatomical block, causing unidirectional blockages and recurrent arrhythmias. Similarly, stem cells are capable of establishing heterotopic excitation foci with cardiac stimulatory activity. Finally, the paracrine factors produced by stem cells can also cause proarrhythmic effects. The review examines the factors that influence the proarrhythmic properties of administered stem cells and the mechanisms of arrhythmia development. The results indicate that further research should be carried out to establish the possible impact of stem cells on the development of arrhythmias.

Recruitment of macrophages and bone marrow stem cells to regenerating liver promoted by sodium phthalhydrazide in mice.

Pharmacological interventions which could be hepatoprotective, depending on bioavailability, anti-inflammatory and macrophage-targeting potential of drugs, are still at early preclinical stages. Existing evidence from many animal models of liver injury, as well as from human data, indicate that pharmacological and/or phytochemical interventions have limited impact on liver recovery. Recent studies on stem cell therapies focused on different cell subsets involved in tissue repair, including monocytes/macrophages and bone marrow cells migrating to the injured liver. Partial hepatectomy (PH) resulted in a rapid increase of monocytes/macrophages in bone marrow and liver, which could be further enhanced by prior treatment of animals with sodium phthalhydrazide. Increased number of proliferating Ki67+ hepatocytes, increased total protein and albumin content in regenerating liver, recruitment of CD172a+ macrophages and more differentiated CD45lowCD117+ bone marrow cells, could be further promoted by the treatment of animals with 2 mg/kg b.w. phthalhydrazide, considered immunomodulatory, antioxidant and macrophage-silencing. Phenotypic polarization of macrophages can possibly explain the macrophage reparative capacities, protective against liver injury. Enhanced macrophage cell recruitment from bone marrow to regenerating liver can be possibly one of important events in hepatic recovery.

Prevalence of arrhythmias in patients with type 2 diabetes and the role of structural changes in myocardium in their development.

OBJECTIVE: The aim of the study was to evaluate the prevalence of arrhythmias in patients with type 2 diabetes and their relationships with the structural parameters of the heart. METHODS: A retrospective case-control study was conducted using clinical and biochemical profiles of patients with diabetes at the Endocrinology Centre and City Clinical Hospital No. 40, Ekaterinburg, Russia. RESULTS: The total study sample included 75 subjects. The average age (SD) was 48.2 (5.6) years, and the mean duration of diabetes (SD) was 6.2 (2.4) years. The most common type of extrasystoles were the single supraventricular extrasystoles, observed in 72.29% of cases (vs 38.89% in the control group) and paired supraventricular extrasystoles, which were identified in 30% of cases (vs 19.44% in the control group). Ventricular cardiac arrhythmias in the form of ventricular extrasystoles (VE) were identified in 25.71% of cases (13.89% in the control group). CONCLUSIONS: This study revealed the signs of the morphological restructuring of the right chambers of the heart and a relatively high prevalence of supraventricular arrhythmias in the early stages of type 2 diabetes. Moreover, according to the results, the incidence of some types of supraventricular arrhythmias and the occurrence of tachycardia episodes in patients with type 2 diabetes mostly depends on the restructuring of the right chambers of the heart, which may be caused by the peculiarities of the cardiac innervation, with the higher density of choline and adrenergic plexuses in the right chambers.