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The gut microbiota (GM), as a forgotten organ, refers to the microbial community that resides in the gastrointestinal tract and plays a critical role in a variety of physiological activities in different body organs. The GM affects its targets through neurological, metabolic, immune, and endocrine pathways. The GM is a dynamic system for which exogenous and endogenous factors have negative or positive effects on its density and composition. Since the mid-twentieth century, laboratory animals are known as the major tools for preclinical research; however, each model has its own limitations. So far, two main models have been used to explore the effects of the GM under normal and abnormal conditions: the isolated germ-free and antibiotic-treated models. Both methods have strengths and weaknesses. In many fields of host-microbe interactions, research on these animal models are known as appropriate experimental subjects that enable investigators to directly assess the role of the microbiota on all features of physiology. These animal models present biological model systems to either study outcomes of the absence of microbes, or to verify the effects of colonization with specific and known microbial species. This paper reviews these current approaches and gives advantages and disadvantages of both models.

Early-life stress negatively alters mammalian brain programming. Environmental enrichment (EE) has beneficial effects on brain structure and function. This study aimed to evaluate the effects of postnatal environmental enrichment on long-term potentiation (LTP) induction in the hippocampal CA1 area of prenatally stressed female rats. The pregnant Wistar rats were housed in a standard animal room and exposed to traffic noise stress 2 hours/day during the third week of pregnancy. Their offspring either remained intact (ST) or received enrichment (SE) for a month starting from postnatal day 21. The control groups either remained intact (CO) or received enrichment (CE). Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area; then, LTP was induced by high-frequency stimulation. Finally, the serum levels of corticosterone were measured. Our results showed that while the prenatal noise stress decreased the baseline responses of the ST rats when compared to the control rats (P < 0.001), the postnatal EE increased the fEPSPs of both the CE and SE animals when compared to the respective controls. Additionally, high-frequency stimulation (HFS) induced LTP in the fEPSPs of the CO rats (P < 0.001) and failed to induce LTP in the fEPSPs of the ST animals. The enriched condition caused increased potentiation of post-HFS responses in the controls (P < 0.001) and restored the disrupted synaptic plasticity of the CA1 area in the prenatally stressed rats. Likewise, the postnatal EE decreased the elevated serum corticosterone of prenatally stressed offspring (P < 0.001). In conclusion, the postnatal EE restored the stress induced impairment of synaptic plasticity in rats' female offspring.

Background and purpose: Alpha-lipoic acid (ALA) is an antioxidant with radioprotective properties. We designed the current work to assess the neuroprotective function of ALA in the presence of oxidative stress induced by radiation in the brainstem of rats. Experimental approach: Whole-brain radiations (X-rays) was given at a single dose of 25 Gy with or without pretreatment with ALA (200 mg/kg BW). Eighty rats were categorized into four groups: vehicle control (VC), ALA, radiation-only (RAD), and radiation + ALA (RAL). The rats were given ALA intraperitoneally 1 h before radiation and killed following 6 h, thereafter superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and total antioxidant capacity (TAC) in the brainstem were measured. Furthermore, a pathological examination was carried out after 24 h, 72 h, and five days to determine tissue damage. Findings/Results: The findings indicated that MDA levels in the brainstem were 46.29 ± 1.64 μM in the RAD group and decreased in the VC group (31.66 ± 1.72 μM). ALA pretreatment reduced MDA levels while simultaneously increasing SOD and CAT activity and TAC levels (60.26 ± 5.47 U/mL, 71.73 ± 2.88 U/mL, and 227.31 ± 9.40 mol/L, respectively). The greatest pathological changes in the rat’s brainstems were seen in RAD animals compared to the VC group after 24 h, 72 h, and 5 days. As a result, karyorrhexis, pyknosis, vacuolization, and Rosenthal fibers vanished in the RAL group in three periods. Conclusion and implications: ALA exhibited substantial neuroprotectivity following radiation-induced brainstem damage.

Background: Facing environmental factors during early postnatal life, directly or indirectly via mother-infant relationships, profoundly affects the structure and function of the mammals’ Central Nervous System (CNS). Objectives: This study aimed to evaluate the effect of morphine consumption during the lactation period on short-term synaptic plasticity of the hippocampal Cornu Ammonis 1 (CA1) neurons in rat offspring. Materials & Methods: In addition to a group of control mother rats (CO), three groups subcutaneously received 5 (M5), 10 (M10), or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, following the stimulation of the Schaffers’ collaterals, basic field Excitatory Post-Synaptic Potentials (fEPSPs) were recorded in their offspring’s hippocampal CA1 neuronal circuits. After the construction input/output curve, paired-pulse stimulations with the inter-stimulus intervals of 20, 80, and 200 ms were applied to determine the short-term synaptic plasticity, and the paired-pulse ratio was evaluated. Results: The baseline synaptic responses of the rats CA1 neurons whose mothers received 10 and 20 mg/kg morphine twice daily during the lactation period decreased compared to the CO animals (P

Abstract Background This study aimed to evaluate the effect of nanoemulsion containing peppermint and rosemary essential oils in rats with osteoarthritis (OA). Methods In this experimental study, we prepared a nanoemulsion containing peppermint and rosemary essential oils by spontaneous emulsification and evaluated the nanoemulsion’s dermal irritation and toxicity. Investigating the analgesic effect of the nanoemulsion, we randomly assigned 36 male rats to 6 groups: Control (saline injection into the knee), osteoarthritis (intra-articular injection of 2 mg monosodium iodoacetate), and four groups of OA treated with nanoemulsion gel, nanoemulsion solution, rosemary and peppermint essential oil gel, or diclofenac sodium. Treatments were administered topically at a dose of 1 ml daily. Using behavioral tests, we assessed pain on days 1, 4, 7, and 14 after injection. Finally, we did the histopathological and biochemical evaluation of rats’ knee joints. Results There were no irritation signs on the animals’ skin after receiving the nanoemulsion and no changes in the hematological and biochemical parameters of rats’ blood compared to the control group. Receiving nanoemulsion decreased the mechanical (P

Objective(s): In addition to genetic factors, environmental phenomena during postnatal age highly affect development and, in turn, function of the brain. The present work evaluates if morphine consumption during lactation period influences the spatial performances and synaptic plasticity in rats at neonatal period of age. Materials and Methods: Three groups of mothers were subcutaneously administered by 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, their offspring were introduced to Morris water maze for assessment of spatial learning and memory. Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area of hippocampus and, then, long term potentiation (LTP) was induced by tetanic stimulation. Results: We found that the M10 and M20 rats spent more time and traveled longer distance to find the hidden platform of maze when compared to the control animals (PConclusion: The present study provides behavioral and electrophysiological proofs for negative effect of morphine on the hippocampal-related function in the neonatally morphine-exposed rats.

Background and Aim: The frequent use of opioids changes function and plasticity of neural circuits. Exposing the immature nervous system to opioids can have deeper and more extensive impacts. The aim of this study was to investigate the effects of morphine consumption during lactation period on learning and memory of rats offspring. Material and Methods: This experimental study included 40 male Wistar rats with age range of 45-50 days. Animals were divided into control group (CO) and 3 experimental groups of rats whose mothers had received subcutaneous injections of 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during lactation period. Spatial learning was evaluated by Morris water maze (MWM) on 4 consecutive days (4 trials/day). Spatial memory retrieval was also evaluated on the last day. Results: Our results indicated that the rats whose mothers had received morphine during lactation period spent more time and traveled more distance to find the hidden platform than the controls in the learning stage. These differences were statistically significant when doses of 10 and 20 mg/kg morphine (P

DNA barcoding is a simple method for the identification of any species using a short genetic sequence from a standard genome section. The present study aimed at examining the nuclear and chloroplast diversity as well as the phylogenetic relationships of eight species of saffron including four spring-flowering and five autumn-flowering species from different parts of Iran, using the nuclear barcode and chloroplast genes to specify their evolutionary pathway and to examine their genetic affinity. First, PCR was performed using the primers designed based on the chloroplast barcodes of matK, trnL, and rbcL, and nuclear barcode of ITS. Then, the PCR products were purified and sequenced. The results of the phylogenetic tree indicated that the examined saffron species of Iran were separated from each other based on the sequences of ITS, matK, and trnL barcodes. In the rbcL barcode, the relationships of a number of species remained unresolved, and this genetic region could not appropriately discriminate the species. The ITS barcode was introduced as the best barcode due to its discriminatory power, a high number of SNPs, and its comprehensiveness in most species. Moreover, the matK and trnL barcodes were identified as complementary barcodes. The use of the four genetic regions in comparison with their individual use has caused these species to be well separated. Overall, the obtained phylogram showed that the cultivated species were more similar to C. pallasii subsp . haussknechtii species.