Opening of T-type Ca2+ channels and activation of HCN channels contribute in stress adaptation in cold water immersion stress-subjected mice

Genome of Russian Snow-White Chicken Reveals Genetic Features Associated with Adaptations to Cold and Diseases

Russian Snow White (RSW) chickens are characterized by high egg production, extreme resistance to low temperatures, disease resistance, and by the snow-white color of the day-old chicks. Studying the genome of this unique chicken breed will reveal its evolutionary history and help to understand the molecular genetic mechanisms underlying the unique characteristics of this breed, which will open new breeding opportunities and support future studies. We have sequenced and made a de novo assembly of the whole RSW genome using deep sequencing (250×) by the short reads. The genome consists of 40 chromosomes with a total length of 1.1 billion nucleotide pairs. Phylogenetic analysis placed the RSW near the White Leghorn, Fayoumi, and Houdan breeds. Comparison with other chicken breeds revealed a wide pool of mutations unique to the RSW. The functional annotation of these mutations showed the adaptation of genes associated with the development of the nervous system, thermoreceptors, purine receptors, and the TGF-beta pathway, probably caused by selection for low temperatures. We also found adaptation of the immune system genes, likely driven by selection for resistance to viral diseases. Integration with previous genome-wide association studies (GWAS) suggested several causal single nucleotide polymorphisms (SNPs). Specifically, we identified an RSW-specific missense mutation in the RALYL gene, presumably causing the snow-white color of the day-old chicks, and an RSW-specific missense mutation in the TLL1 gene, presumably affecting the egg weight.

The role of HCN channels on the effects of T-type calcium channels and GABAA receptors in the absence epilepsy model of WAG/Rij rats

In this study we used ivabradine (IVA), a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker, to identify its effect on spike-wave discharges (SWDs); and aimed to determine the role of IVA on the effects of T-type calcium channel blocker NNC 55-0396, GABAA receptor agonist muscimol and antagonist bicuculline in male WAG/Rij rats. After tripolar electrodes for electrocorticogram (ECoG) recordings were placed on the WAG/Rij rats' skulls, 5, 10, and 20 mg/kg IVA were intraperitoneally administered for 7 consecutive days and ECoG recordings were obtained on days 0th, 3rd, 6th, and 7th for three hours before and after injections. While acute injection of 5, 10, and 20 mg/kg IVA did not affect the total number and the mean duration of SWDs, subacute administration (7 days) of IVA decreased the SWDs parameters 24 hours after the 7th injection. Interestingly, when IVA was administered again 24 hours after the 6th IVA injection, it increased the SWDs parameters. Western-blot analyses showed that HCN1 and HCN2 expressions decreased and HCN4 increased in the 5-month-old WAG/Rij rats compared to the 1-month-old WAG/Rij and 5-month-old native Wistar rats, while subacute IVA administration increased the levels of HCN1 and HCN2 channels, except HCN4. Subacute administration of IVA reduced the antiepileptic activity of NNC, while the proepileptic activity of muscimol and the antiepileptic activity of bicuculline were abolished. It might be suggested that subacute IVA administration reduces absence seizures by changing the HCN channel expressions in WAG/Rij rats, and this affects the T-type calcium channels and GABAA receptors.

Diazepam ameliorates altered proinflammatory and cardiac markers in stress exposed rats

Regular exposure to stress causes alteration in biochemical parameter but till date no specific medicine prescribed for controlling it. Current study aimed to determine the effect of Diazepam on proinflammatory and cardiac markers in stress exposed rats. Male Wistar rats were divided into four groups with six animals in each group for 90 days study. Group-1 served as a Normal Control (NC), Groups-2, as a Disease Control (DC), Group-3 as a Diazepam Control (DMC) and Group-4 as a Disease + Diazepam Treatment (DT). DMC and DT animals exposed to regular stress by forced swimming exercise method for 90 days. DMC and DT received 5 mg/kg, p.o the daily dose of Diazepam. At the end of the protocol, animals were sacrificed. The level of serum proinflammatory marker interleukin-6 in DC increased significantly (p < 0.001) while restored significantly (p < 0.001) in DT. Level of interleukin-10 in DC decreased significantly (p < 0.001) while restored significantly (p < 0.001) in DT. Level of fibrinogen was also increased by stress, which was restored significantly (p < 0.05) by diazepam. Increased level of Creatine kinase-MB (CK-MB) by stress was restored significantly (p < 0.05) by diazepam. The level of cortisol was increased also significantly (p < 0.001) and restored to normal by diazepam. The level of C-reactive protein (CRP) and cholesterol was increased significantly (p < 0.01; p < 0.001) by stress while restored significantly (p < 0.01; p < 0.001) by diazepam. Findings from results suggest that diazepam ameliorates altered proinflammatory and cardiac markers in stress exposed rats.