Intra hippocampal injection of testosterone impaired acquisition, consolidation and retrieval of inhibitory avoidance learning and memory in adult male rats

The hippocampus is essentially involved in learning and memory, and is known to be a target for androgen actions. Androgen receptors are densely expressed in CA1 of rat hippocampus, and mediate the effects of testosterone (T) on learning and memory. T depletion or administration can modulate neural function and cognitive performance. We conducted series of experiments to further investigate the effect of castration or intra hippocampal injection of T on acquisition, consolidation and retrieval of inhibitory avoidance learning and memory. Male adult rats were bilaterally cannulated into CA1 of hippocampus, and then received T (1, 10, 20, 40 and 80mug/0.5mul/side) or vehicle (DMSO), 30min before training, immediately after training and 30min before retrieval in inhibitory avoidance task. Castration was made by gonadectomy of male rats and behavioral tests performed 4 weeks later. Our results showed that gonadectomy of male rats did not influence performance on inhibitory avoidance task, as compared to sham-operated rats. We have also found that pre-training, post-training and pre-retrieval intra CA1 injections of T significantly decreased step-through latencies in inhibitory avoidance learning at doses 1 and 80, 20, and 20 and 40mug/0.5mul/side, respectively. The data suggest that intra CA1 administration of T could impair learning and memory acquisition, consolidation and retrieval, while systemic androgen's depletion have no effect on memory, in inhibitory avoidance task.     

Effects of Angipars on oxidative inflammatory indices in a murine model of periodontitis

Background and the purpose of the study

There are strong evidences linking overproduction of reactive oxygen species and periodontal diseases. The aim of this study was to evaluate efficacy of Angipars a natural potent anti oxidative agent on markers of the oxidative damages and periodontal inflammation in the rat.

Methods

Periodontitis was induced by single injection of lipopolysaccharide (LPS) from E. coli (10 µg/µl saline) into rat mandibular gingiva. After 10 days, animals in the test group received Angipars (2.1 mg/kg) by gavage once a day and those of control group received same amount of vehicle. The amount of interleukin (IL)-1β, lipid peroxidation (LPO), and 8-hydroxydeoxyguanosine (8-OHdG) were measured in gingival biopsy samples and the degree of apical migration of junctional epithelium (JE), alveolar bone resorption, and the number of polymorphonuclears (PMN) were evaluated by histological analysis of block samples of the left mandibular first molars.

Results

Periodontitis group showed a significant increase in periodontal IL-1β, LPO, 8-OHdG, apical migration of JE, alveolar bone resorption and number of PMNs. Angipars treatment resulted in a significant decrease in gingival IL-1β, LPO, 8-OHdG and the apical migration of JE; however, the reduction of alveolar bone resorption was not significant. The number of PMN increased significantly after treatment with Angipars. While intake of vehicle resulted in a significant decrease in gingival IL-1β and LPO, the reduction of 8-OHdG, apical migration of JE, and alveolar bone resorption were not significant. Interestingly, PMNs were increased in groups received Angipars or the vehicle.

Conclusion

From the results of this study, it seems that Angipars is beneficial in periodontitis by reduction of inflammatory and oxidative damage. Unexpected increase of PMN count by Angipars strengthens the hypothesis that chronic inflammatory disorders like periodontitis may need more time to get best advantage of anti oxidative drugs like Angipars. Regarding role of microbes in pathogenesis of periodontitis, further studies should be focused on antimicrobial effects of Angipars.     

Changes in hippocampal connexin 36 mRNA and protein levels during epileptogenesis in the kindling model of epilepsy

Objective

Identification of key molecular changes occurring during epileptogenesis provides better understanding of epilepsy and helps to develop strategies to modify those changes and thus, block the epileptogenic process. Gap junctional communication is thought to be involved in epileptogenesis. This communication can be affected by changes in expression of gap junctional protein subunits called connexins (Cxs). One of the main brain regions involved in epileptogenesis is the hippocampus in which there is a network of gap junctional communication between different cell types.

Method

Cx36 and Cx43 expressions at both mRNA and protein level were measured in rat hippocampus during epileptogenesis in the kindling model of epilepsy.

Results

Cx36 expression at both mRNA and protein level was upregulated during acquisition of focal seizures but returned to basal level after acquisition of secondarily-generalized seizures. No change in Cx43 gene and protein expression was found during kindling epileptogenesis.

Conclusion

These results further point out the significance of Cx36 as a target to modify epileptogenic process and to develop antiepileptogenic treatments.     

Severe SARS‐CoV‐2 infection in a 32‐week pregnant woman treated with Remdesivir‐Dexamethasone combination therapy: A case report

This study shows that remdesivir and dexamethasone combination therapy can be considered as a suitable treatment choice for pregnant women infected with COVID‐19. It is worth mentioning that more studies are required to evaluate the efficacy and side effects of remdesivir monotherapy and its combination with dexamethasone during pregnancy.