E. coli growth curve assay in BG-11 + sucrose v1

To obtain growth curves of KJK01 and pCSCX-KJK01 in BG-11 + sucrose and to characterize their growth. This also serves to estimate sucrose consumption and butanol production over time. This can be adapted for any other bacteria as well by giveing proper growth conditions, and using appropriate wavelength to measure the OD and giving proper time intervals based on whether the bacteria is slow growing or fast growing.

Maternal sucrose consumption alters behaviour and steroids in adult rat offspring

Maternal diets can have dramatic effects on the physiology, metabolism, and behaviour of offspring that persist into adulthood. However, the effects of maternal sucrose consumption on offspring remain unclear. Here, female rats were fed either a sucrose diet with a human-relevant level of sucrose (25% of kcal) or a macronutrient-matched, isocaloric control diet before, during, and after pregnancy. After weaning, all offspring were fed a standard low-sucrose rodent chow. We measured indicators of metabolism (weight, adipose, glucose tolerance, liver lipids) during development and adulthood (16-24 wk). We also measured food preference and motivation for sugar rewards in adulthood. Finally, in brain regions regulating these behaviours, we measured steroids and transcripts for steroidogenic enzymes, steroid receptors, and dopamine receptors. In male offspring, maternal sucrose intake decreased body mass and visceral adipose, increased preference for high-sucrose and high-fat diets, increased motivation for sugar rewards, and decreased mRNA levels of Cyp17a1 (an androgenic enzyme) in the nucleus accumbens. In female offspring, maternal sucrose intake increased basal corticosterone levels. These data demonstrate the profound, enduring, diverse, and sex-specific effects of maternal sucrose consumption on offspring phenotype.

Sucrose Consumption Alters Serotonin/Glutamate Co-localisation Within the Prefrontal Cortex and Hippocampus of Mice

The overconsumption of sugar-sweetened food and beverages underpins the current rise in obesity rates. Sugar overconsumption induces maladaptive neuroplasticity to decrease dietary control. Although serotonin and glutamate co-localisation has been implicated in reward processing, it is still unknown how chronic sucrose consumption changes this transmission in regions associated with executive control over feeding—such as the prefrontal cortex (PFC) and dentate gyrus (DG) of the hippocampus. To address this, a total of 16 C57Bl6 mice received either 5% w/v sucrose or water as a control for 12 weeks using the Drinking-In-The-Dark paradigm (n = 8 mice per group). We then examined the effects of chronic sucrose consumption on the immunological distribution of serotonin (5-HT), vesicular glutamate transporter 3 (VGLUT3) and 5-HT+/VGLUT3+ co-localised axonal varicosities. Sucrose consumption over 12 weeks decreased the number of 5-HT–/VGLUT3+ and 5-HT+/VGLUT3+ varicosities within the PFC and DG. The number of 5-HT+/VGLUT3– varicosities remained unchanged within the PFC but decreased in the DG following sucrose consumption. Given that serotonin mediates DG neurogenesis through microglial migration, the number of microglia within the DG was also assessed in both experimental groups. Sucrose consumption decreased the number of DG microglia. Although the DG and PFC are associated with executive control over rewarding activities and emotional memory formation, we did not detect a subsequent change in DG neurogenesis or anxiety-like behaviour or depressive-like behaviour. Overall, these findings suggest that the chronic consumption of sugar alters serotonergic neuroplasticity within neural circuits responsible for feeding control. Although these alterations alone were not sufficient to induce changes in neurogenesis or behaviour, it is proposed that the sucrose consumption may predispose individuals to these cognitive deficits which ultimately promote further sugar intake.

Antidepressant like activity of Buspirone but not ondensetron in combination with Fluoxetine or Desipramine in mice

Background: The involvement of one or more 5-HT receptor sub-types in the pathophysiology of depression is still unclear. The study was performed to investigate the effect of ondansetron and buspirone on depression, and their interaction with fluoxetine or desipramine.Methods: The mice were administered ondansetron, buspirone alone and in combinations with fluoxetine or desipramine for 21 days, and the antidepressant effect was assessed by the immobility period and the sucrose consumption, on the tail suspension test (TST) and the chronic mild stress (CMS) models, respectively.Results: Both ondansetron and buspirone when given alone demonstrated slight non-significant decrease in the immobility time. Ondensetron when given in combination with fluoxetine (10 mg/kg; i.p.) and desipramine (15 mg/kg; i.p.), showed significant decrease in immobility time in comparison to the control group only. On the other hand, both the combinations of buspirone, either with fluoxetine or desipramine showed significant decrease in the immobility time when compared to the respective group. In CMS, the fluoxetine, desipramine, ondansetron, and buspirone showed gradual increase in the sucrose consumption, at the end of 4th, 5th, and 6th week, but the significant effect was observed only at the end of 6th week, as compared to the control. The combination of buspirone with desipramine but not with fluoxetine showed significant increase in sucrose consumption when compared to respective group.Conclusions: Therefore, the study indicates that both buspirone and ondansetron have a potential antidepressant like action, although buspirone has shown better antidepressant activity than ondansetron as observed in various combination groups.

Supramammillary neurons projecting to the septum regulate dopamine and motivation for environmental interaction in mice

The supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to elucidate how SuM neurons mediate such effects. Using optogenetics, we found that the excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by their projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway regulates arousal that reinforces and energizes behavioral interaction with the environment.

Coherent activity at three major lateral hypothalamic neural outputs controls the onset of motivated behavior responses

The lateral hypothalamus (LH) plays an important role in motivated behavior. However, it is not known how LH neural outputs dynamically signal to major downstream targets to organize behavior. We used multi-fiber photometry to show that three major LH neural outputs projecting to the dorsal raphe nucleus (DRN), ventral tegmental area (VTA), and lateral habenula (LHb) exhibit significant coherent activity in mice engaging motivated responses, which decrease during immobility. Mice engaging active coping responses exhibit increased activity at LH axon terminals that precedes an increase in the activity of serotonin neurons and dopamine neurons, indicating that they may play a role in initiating active responses stemming from LH signal transmissions. The optogenetic activation of LH axon terminals in either the DRN, VTA, or LHb was sufficient to increase mobility but had different effects on passive avoidance and sucrose consumption, suggesting that LH outputs use complementary mechanisms to control behavioral responses. Our results support the notion that the three LH neural outputs play complementary roles in initiating motivated behaviors.

Rhodosporidium sp. DR37: a novel strain for production of squalene in optimized cultivation conditions

Background Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, a new strain of Rhodosporidium sp. was isolated and identified, and its potential was investigated for production of squalene under various cultivation conditions. Results In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on modified YEPD medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Also, squalene content was obtained as 13.9% of total lipid. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20% v/v), pH 7, 25 °C) allowed highest squalene accumulation (619 mg/L) and content (21.6% of total lipid) in Rhodosporidium sp. DR37. Moreover, kinetic parameters including maximum specific cell growth rate (μmax, h−1), specific lipid accumulation rate (qp, h−1), specific squalene accumulation rate (qsq, h−1) and specific sucrose consumption rate (qs, h−1) were determined in optimized medium as 0.092, 0.226, 0.036 and 0.010, respectively. Conclusions This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. These findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale. Graphic abstract

Daphnetin Ameliorates Corticosterone-Induced Depressive-Like Behavior and Oxidative Stress in Mice Via Nuclear Factor Erythroid 2-Related Factor/Heme Oxygenase-1 Pathway

We have investigated the effect of daphnetin on depressive-like behavior and oxidative stress caused by corticosterone in mice. To this end, we have analyzed the effect of corticosterone alone and combination of corticosterone and daphnetin on three behavioral indices of depressive-like behavior - sucrose consumption rate, forced swimming test, and tail suspension test as well as biochemical markers of oxidative stress - malondialdehyde, nitrite, protein carbonyl, nonprotein sulfhydryl and glutathione contents as well as hippocampal cell apoptosis. The results support the conclusion that daphnetin diminished corticosterone induced depressive like behavior and oxidative stress by activating Nrf2/HO-1 pathway.