Days Of Habituation Research Articles

Positive correlation between n−6 : n−3 PUFA ratio intake with serum oxHDL/HDL-c ratio in patients with coronary artery disease

Background Coronary artery disease (CAD) is one of the most prevalent cardiovascular diseases where serum lipoprotein oxidation plays a significant role. Polyunsaturated fatty acids (PUFA) n−6 : n−3 unbalance ratio consumption, affects lipoprotein oxidation, and inflammation processes. This study aimed to analyze the relationship between n−6 : n−3 PUFA ratio intake with oxidized lipoproteins in individuals with CAD. Methods A cross-sectional study was performed including 105 subjects (51 diagnosed with CAD and 54 non-CAD) from western Mexico. Dietary information was collected using a habitual day food record. Serum oxidized low-density lipoprotein (oxLDL) and oxidized high-density lipoprotein (oxHDL) concentrations were quantified by enzyme linked immunosorbent assay. Results CAD subjects had higher oxHDL/HDL cholesterol (HDL-c) ratio [0.102 (0.092–0.112) vs. 0.080 (0.070–0.090), P = 0.004] and oxLDL/LDL cholesterol (LDL-c) ratio [129.2 (108–150.4) vs. 59.7 (39.3–80), P < 0.001] compared to non-CAD subjects. Risk factors associated with CAD were a high n−6 : n−3 PUFA ratio (odds ratio, OR = 2.3, P = 0.046), hypoalphalipoproteinemia in men (OR = 3.2, P = 0.014), moderate/high tobacco index (OR = 6.33, P = 0.003), elevated waist circumference in women (OR = 7, P = 0.004), hypertension (OR = 21.14, P < 0.001), and type 2 diabetes (OR: 25, P < 0.001). The oxHDL/HDL-c ratio was positively associated with the n−6 : n−3 PUFA ratio [r 2 = 28.3, B = 0.002 (0.001–0.003), P < 0.001] in CAD patients. Conclusions This study showed that a higher n−6 : n−3 PUFA ratio intake correlates with higher serum oxHDL/HDL-c in CAD patients.

Gut microbiome is dispensable for normal respiratory function and respiratory chemoreflex

Increasing evidence indicates that gut microbiota can influence changes in respiratory homeostasis. Alterations to the gut microbiome have been hypothesized to play roles in autoimmune diseases, social behavioral deficits, and metabolic diseases such as diabetes and cardiovascular disease. We therefore aimed to determine if a model of gut dysbiosis, the absence of a gut microbiome, would result in alterations to respiratory homeostasis. After 5 days of habituation inside the Gnotobiotic animal facility, we assayed 8-week-old C57Bl/6J germ-free (GF, n=24) and specific-pathogen-free (SPF, n=24) control mice under normoxic (21% O2,79% N2) conditions, followed by a hypercapnic challenge (5% CO2, 21% O2, 74% N2) and hypoxic challenge (10% O2, 90% N2). Importantly, this germfree model does not involve treatment with high-dose antibiotics, which have been implicated in neurotoxic sequela. Whole-body flow through plethysmography was used to monitor respiratory function and metabolic demand in conscious and unrestrained animals. Recordings were interrogated using our newly published open-source software, Breathe Easy, for breath cycle duration, respiratory rate (Vf), tidal volume (VT), minute ventilation (VE), oxygen consumption (VO2), and minute ventilation normalized by oxygen consumption (VE/VO2) during room air, initial hypoxic and hypercapnic exposures, and steady-state hypoxic and hypercapnic respiratory responses. A linear mixed effects model with a Tukey post-hoc test was performed to test for significant differences wherein respiratory outcomes were dependent variables, and strain and sex were independent variables. In male mice, there was a significant decrease in breath cycle duration during room air in GF compared to SPF controls. We also saw a significant decrease in ventilatory equivalents of oxygen in the initial hypoxic response in GF mice compared to SPF controls in males, but not in the steady-state of hypoxic exposure. Finally, we note a significant increase in oxygen consumption in females during room air measurements. Of note, female mice showed significant irregularity in all respiratory parameters except oxygen consumption whereas males only showed significant irregularity in breath cycle duration during hypoxic steady-state and the hypercapnic steady-state, and tidal volume in the initial hypoxic response. While there are significant changes, it remains to be determined what the underlying mechanisms are and how they may play a contributory role in pathophysiologies co-morbid with gut microbiome dysregulation. Taken together, these results suggest that the gut microbiome is largely dispensable for normal respiratory function and respiratory chemoreflexes in adult mice and that the lack of a gut microbiome, a model of gut dysbiosis, does not result in broad significant changes in respiratory homeostasis. NIH: 1F32HL160073-01A1, R01HL130249 44617-S4. BCM McNair Scholar Program, March of Dimes Basil O'Connor Research Award, Parker B. Francis Fellowship, CJ Foundation for SIDS. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Even or skewed dietary protein distribution is reflected in the whole-body protein net-balance in healthy older adults: A randomized controlled trial

For older adults, the dietary protein intake has shown to be skewed towards the evening meal. Resultingly, the vital source of essential amino acids could be insufficient after some meals, while after the evening meal the dietary protein could be suboptimally utilized for protein synthesis. The present study explored if an even distribution of the protein intake could improve the dietary amino acid absorption and whole-body protein net-balance. Twenty-four healthy elderly males and females were included in a randomized controlled trial. Ten days of habituation to either an EVEN (n=12) or SKEWED (n=12) protein intake, was followed by a trial day. The total protein intake was controlled at 1.5g/kg LBM, divided into 30% at each main meal in EVEN, and into 15% at breakfast and lunch and 60% at dinner in SKEWED. Snacks with 5% of the protein intake were served between meals. Energy intake in the meals and snacks were equal in both groups. Intrinsically labelled 2H5-phenylalanine minced meat was served as the dietary protein to assess the amino acid absorption. On the trial day, infusion of 2H8-phenylalanine and 2H2-tyrosine, and blood samples taken over 11h were used to measure whole-body protein turnover. Vastus lateralis muscle biopsies were taken to measure 9h muscle protein FSR. Amino acid absorption rates and concentrations were greater in EVEN compared to SKEWED protein intake. Whole-body protein breakdown rates were lower with similar protein synthesis rates, and consequently the net-balance was greater in EVEN after breakfast and lunch compared to SKEWED and were the same in both groups after dinner. Muscle protein FSR were not different between EVEN and SKEWED. The whole-body protein net-balance was more positive in EVEN compared to SKEWED for an extended time of the measured period, driven by a lower whole-body protein breakdown in EVEN. NCT03870425, https://clinicaltrials.gov/ct2/show/NCT03870425.

An increase in spontaneous activity mediates visual habituation.

SUMMARYThe cerebral cortex is spontaneously active, but the function of this ongoing activity remains unclear. To test whether spontaneous activity encodes learned experiences, we measured the response of neuronal populations in mouse primary visual cortex with chronic two-photon calcium imaging during visual habituation to a specific oriented stimulus. We find that, during habituation, spontaneous activity increases in neurons across the full range of orientation selectivity, eventually matching that of evoked levels. This increase in spontaneous activity robustly correlates with the degree of habituation. Moreover, boosting spontaneous activity with two-photon optogenetic stimulation to the levels of visually evoked activity accelerates habituation. Our study shows that cortical spontaneous activity is linked to habituation, and we propose that habituation unfolds by minimizing the difference between spontaneous and stimulus-evoked activity levels. We conclude that baseline spontaneous activity could gate incoming sensory information to the cortex based on the learned experience of the animal.

An assessment of the spontaneous locomotor activity of BALB/c mice

The surrounding environment affects the behavior of an animal. Therefore, long-term observation of an animal's behavior in its natural breeding environment is an effective approach to predict and understand animal behavior in greater detail. Spontaneous locomotor activity (SLA), the movement of animals in their breeding environment, is one of the most important behavioral indices for experimental animals. We here established an SLA measurement system using image analyses to obtain basic data from BALB/c mice. To record the movement of the mice, we used an infrared video camera. SLA of mice were calculated by detecting their geometric center in each frame. This system could detect the mouse correctly more than 99.999% in all frames. Further, we investigated the effects of habituation, age, and sex on the SLA of BALB/c mice. Three days of habituation were required to decrease the SLA of mice placed in novel cages. The 16- and 32-week-old mice were less active than 4-week-old mice. No significant differences were detected between males and females. We also found that BALB/c and C57BL/6 mice differed in their active and resting rhythms. In conclusion, we developed an SLA measurement system and obtained basic SLA data from BALB/c mice.

High dietary ω-6:ω-3 PUFA ratio and simple carbohydrates as a potential risk factors for gallstone disease: A cross-sectional study

Background & aimsGallstone disease (GD) is a major cause for consultation at general surgery services worldwide. In fact, GD has a strong relationship with environmental factors. However, specific characteristics in the Mexican population have not been established. The aim of this study was to compare the dietary components, physical activity, body composition and serum lipids in women with and without GD. Methods54 women with GD and 75 without GD from West Mexico were enrolled in a cross-sectional study. Dietary intake was obtained through a habitual day food record and analyzed using the Nutritionist Pro™ software. Physical activity was evaluated in accordance with WHO recommendations. Body fat percentage (BF%) was estimated by bioimpedance (InBody 370) and serum lipids were measured using dry chemistry (Vitros-250 Analyzer). Student's t-test and binary logistic regression model were used. ResultsWomen with GD presented a higher BF% (40 ± 8.7 vs 35.21 ± 9.8%, p = 0.004), an elevated dietary ω-6:ω-3 polyunsaturated fatty acids (PUFA) ratio (18.0 ± 11.4 vs 10.9 ± 4.7, p<0.001) and a higher simple carbohydrates (sCH) intake (28.3 ± 17.8 vs 13.23 ± 8.2%, p<0.001) as well as lower HDL-cholesterol levels (37.43 ± 8.5 vs 46.6 ± 12.02 mg/dL, p<0.001) compared with women without GD. Furthermore, it was foun d a higher ω-6:ω-3 PUFA ratio (OR: 3.9, 95% CI 1.52–10.38, p = 0.005) and excessive sCH consumption (OR: 7.4, 95% CI 1.92–28.65, p = 0.004). ConclusionWe suggest that a high dietary ω-6:ω-3 PUFA ratio and an excessive sCH intake are associated with an increased risk of GD in women.

157 The Circadian Variation of Sleep in Postmenopausal Women

Abstract Introduction During menopause, 40-60% of women report sleep complaints. Despite the fact that menopause is associated with fluctuations in sex hormones that can affect circadian physiology, the role of circadian factors in sleep disturbances after menopause is not well understood. The present study aims to understand the circadian variation of sleep occurring after menopause. Methods Eight healthy postmenopausal women (PMW; 54.8±3.4 years, one taking hormones) without sleep complaints were enrolled and compared to previously-collected data from 12 healthy young women (YW; 25.8±3.4 years) in mid-follicular phase. Following an 8-h baseline sleep period aligned to their habitual sleep times, participants underwent a 48-h (PMW) or 72-h (YW) ultradian sleep-wake cycle procedure (USW) with 60-min wake episodes alternating with 60-min nap opportunities. Sleep was recorded with polysomnography. Circadian parameters (amplitude, phase) of core body temperature (CBT) and sleep were assessed and compared using mixed-effects linear models on the first 48 hours of USW. Sleep parameters, including total sleep time (TST), arousals, sleep onset latency (SOL), stages N1, N2, N3, REM, and wake, were compared between groups during baseline and USW. Results PMW presented earlier habitual bedtimes (23:07±00:11 vs 00:13±00:12) and rise-times (07:07±00:11 vs 08:13±00:12) compared to YW (p=0.005). There were no differences in amplitude, phase, or phase angle of CBT. An advanced acrophase of REM sleep (p=0.034) and lower amplitudes of TST, arousals, SOL, N3, and wake, were observed in PMW vs YW (p≤0.05). During baseline, PMW presented more stage N1 (p=0.030) and arousals (p&amp;lt;0.001) than YW. During USW, group effects were observed, with more stage N1 (p=0.007) and N2 (p=0.0007) in PMW vs YW. Significant interactions showed greater TST (p=0.009), shorter SOL (p=0.001), and more arousals (p=0.027) in PMW during the habitual day. Conclusion The primary finding in this small group of PMW with no sleep complaints was a general increase in light sleep and arousals across circadian phases. No differences in CBT rhythms were observed, whereas small differences in the circadian variation of TST, N3, and REM sleep were observed. Further studies are needed to clarify the role of circadian processes on sleep in PMW. Support (if any) Study supported by the Canadian Institutes of Health Research.

Early social experience has life-long effects on baseline but not stress-induced cortisol levels in a cooperatively breeding fish

In cooperatively breeding cichlid fish, the early social environment has lifelong effects on the offspring's behaviour, life-history trajectories and brain gene expression. Here, we asked whether the presence or absence of parents and subordinate helpers during early life also shapes fluctuating levels of cortisol, the major stress hormone in the cichlid Neolamprologus pulcher. To non-invasively characterize baseline and stress-induced cortisol levels, we adapted the ‘static’ holding-water method often used to collect waterborne steroid hormones in aquatic organisms by including a flow-through system allowing for repeated sampling without handling of the experimental subjects. We used 8-year-old N. pulcher either raised with (+F) or without (−F) parents and helpers in early life. We found that N. pulcher have a peak of their circadian cortisol cycle in the early morning, and that they habituated to the experimental procedure after four days. Therefore, we sampled the experimental fish in the afternoon after four days of habituation. −F fish had significantly lower baseline cortisol levels, whereas stress-induced cortisol levels did not differ between treatments. Thus, we show that the early social environment has life-long effects on aspects of the physiological stress system of the Hypothalamic-Pituitary-Interrenal (HPI) axis. We discuss how these differences in physiological state may have contributed to the specialization in different social and life-history trajectories of this species.

Food insecurity is associated with compromised dietary intake and quality among Lebanese mothers: findings from a national cross-sectional study.

Examine the associations between household food insecurity (HFI) with sociodemographic, anthropometric and dietary intakes of mothers. Cross-sectional survey (2014-2015). In addition to a sociodemographic questionnaire, data collection included the validated Arabic version of the Household Food Insecurity Access Scale, which was used to evaluate HFI. Dietary intake was assessed using 24-h dietary recall of a single habitual day, and maternal BMI was calculated based on weight and height measurements. Associations between HFI and maternal dietary intake (food groups, energy and macronutrients' intake) were examined. Simple and multiple logistic regression analyses were conducted to explore the associations between HFI status with odds of maternal overweight and measures of diet quality and diversity (Healthy Eating Index (HEI) and Minimum Dietary Diversity for Women of Reproductive Age (MDD-W)). Lebanon. Mothers, nationally representative sample of Lebanese households with children (n 1204). HFI was experienced among almost half of the study sample. Correlates of HFI were low educational attainment, unemployment and crowding. Significant inverse associations were observed between HFI and dietary HEI (OR 0·64, 95 % CI 0·46, 0·90, P = 0·011) and MDD-W (OR 0·6, 95 % CI 0·42, 0·85, P = 0·004), even after adjusting for socioeconomic correlates. No significant association was observed between HFI and odds of maternal overweight status. HFI was associated with compromised maternal dietary quality and diversity. Findings highlight the need for social welfare programmes and public health interventions to alleviate HFI and promote overall health and wellbeing of mothers.

Repeatability analysis improves the reliability of behavioral data.

Reliability of data has become a major concern in the course of the reproducibility crisis. Especially when studying animal behavior, confounding factors such as novelty of the test apparatus can lead to a wide variability of data which may mask treatment effects and consequently lead to misinterpretation. Habituation to the test situation is a common practice to circumvent novelty induced increases in variance and to improve the reliability of the respective measurements. However, there is a lack of published empirical knowledge regarding reasonable habituation procedures and a method validation seems to be overdue. This study aimed at setting up a simple strategy to increase reliability of behavioral data measured in a familiar test apparatus. Therefore, exemplary data from mice tested in an Open Field (OF) arena were used to elucidate the potential of habituation and how reliability of measures can be confirmed by means of a repeatability analysis using the software R. On seven consecutive days, male C57BL/6J, BALB/cJ and 129S1/SvImJ mice were tested in an OF arena once daily and individual mouse behavior was recorded. A repeatability analysis was conducted with regard to repeated trials of habituation. Our data analysis revealed that monitoring animal behavior during habituation is important to determine when individual differences of the measurements are stable. Repeatability values from distance travelled and average activity increased over the habituation period, revealing that around 60% of the variance of the data can be explained by individual differences between mice. The first day of habituation was significantly different from the following 6 days. A three-day habituation period appeared to be sufficient in this study. Overall, these results emphasize the importance of habituation and in depth analysis of habituation data to define the correct starting point of the experiment for improving the reliability and reproducibility of experimental data.

Headpost Surgery for in vivo Electrophysiological Recording in the Mouse Inferior Colliculus during Locomotion.

The inferior colliculus (IC) is a critical midbrain integration center for auditory and non-auditory information. Although much is known about the response properties of the IC neurons to auditory stimuli, how the IC neural circuits function during movement such as locomotion remains poorly understood. Mice offer a valuable model in this respect, but previous studies of the mouse IC were performed in anesthetized or restrained preparations, making it difficult to study the IC function during behavior. Here we describe a neural recording protocol for the mouse IC in which mice are head-fixed, but can run on a passive treadmill. Mice first receive a headpost surgery, and become habituated to head-fixing while being on a treadmill. Following a few days of habituation, neural recordings of the IC neuron activity are performed. The neural activity can be compared across different behavioral conditions, such as standing still versus running on a treadmill. We describe how to overcome the challenges of headpost surgery for awake IC recording, presented by the location and overlying bones. This protocol allows investigations of the IC function in behaving mice, while allowing precise stimulus control and the use of recording methods similar to those for anesthetized preparations.

Gut Microbiome is Dispensable for Normal Respiratory Function and Chemoreflexes in Adult Mice

Increasing evidence indicates that changes in respiratory homeostasis and disordered breathing, such as obstructive sleep apnea, intermittent hypoxia or exercise can modulate or are associated with changes in the gut microbiome. Additionally, alterations to gut microbiome have been hypothesized to play a role in autoimmune diseases, social behavioral deficits, and metabolic diseases such as diabetes and cardiovascular disease. We therefore aimed to determine if a model of gut dysbiosis, the absence of a gut microbiome, would result in alterations to respiratory homeostasis.In order to determine if the lack of a gut microbiome would alter respiratory homeostasis, we assayed 8‐week‐old C57bl6J germ‐free (GF, n=24) and specific‐pathogen‐free (SPF, n=24) mice under normoxic (21%O2, 79%N2) conditions and challenging them with hypercapnic (5%CO2, 21%O2, 74%N2) and hypoxic (10%O2, 90%N2) environments. Whole‐body flow through plethysmography was used to monitor respiratory function and metabolic demand in conscious and unrestrained animals. The experimental protocol consisted of 5 days of habituation to human handling and chamber acclimation prior to respiratory assessment. GF mice habituation was performed inside the germ‐free isolator prior to exiting them for testing. To determine if gut colonization of GF mice may alter respiratory function, 12 GF mice assayed by plethysmography and then orally inoculated with fecal samples from SPF donor mice, while 12 SPF control mice were assayed for respiratory function and then inoculated with sterile saline. All animals were then placed back into the SPF facility for 3 weeks to allow for gut colonization.Mice were analyzed for respiratory rate (Vf), tidal volume (VT), minute ventilation (VE), oxygen consumption (VO2), and minute ventilation normalized by oxygen consumption (VE/VO2). For GF vs SPF experiments 2‐way ANOVA was performed with Bonferroni multiple comparison correction and a p&lt;0.05 was used to indicate statistical significance. No difference between GF and SPF mice for any parameter was found. For GF gut recolonization experiments, no significant difference was found within group comparing pre‐ and post‐recolonization and between groups. Pre‐ and post‐recolonization data was compared using a paired t‐test while the comparison between groups was done by a 2‐way ANOVA with Bonferroni multiple comparison correction. A p&lt;0.05 was used to indicate statistical significance.Overall these results suggest that the gut microbiome is dispensable for normal respiratory function and respiratory chemoreflexes in adult mice and that the lack of a gut microbiome, a model of gut dysbiosis, does not result in significant changes in respiratory homeostasis.Support or Funding InformationMcNair Medical InstituteThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Novel Object Recognition Test for the Investigation of Learning and Memory in Mice

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is fairly simple and can be completed over 3 days: habituation day, training day, and testing day. During training, the mouse is allowed to explore 2 identical objects. On test day, one of the training objects is replaced with a novel object. Because mice have an innate preference for novelty, if the mouse recognizes the familiar object, it will spend most of its time at the novel object. Due to this innate preference, there is no need for positive or negative reinforcement or long training schedules. Additionally, the ORT can also be modified for numerous applications. The retention interval can be shortened to examine short-term memory, or lengthened to probe long-term memory. Pharmacological intervention can be used at various times prior to training, after training, or prior to recall to investigate different phases of learning (i.e., acquisition, early or late consolidation, or recall). Overall, the ORT is a relatively low-stress, efficient test for memory in mice, and is appropriate for the detection of neuropsychological changes following pharmacological, biological, or genetic manipulations.

Novel Object Recognition Test for the Investigation of Learning and Memory in Mice.

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is fairly simple and can be completed over 3 days: habituation day, training day, and testing day. During training, the mouse is allowed to explore 2 identical objects. On test day, one of the training objects is replaced with a novel object. Because mice have an innate preference for novelty, if the mouse recognizes the familiar object, it will spend most of its time at the novel object. Due to this innate preference, there is no need for positive or negative reinforcement or long training schedules. Additionally, the ORT can also be modified for numerous applications. The retention interval can be shortened to examine short-term memory, or lengthened to probe long-term memory. Pharmacological intervention can be used at various times prior to training, after training, or prior to recall to investigate different phases of learning (i.e., acquisition, early or late consolidation, or recall). Overall, the ORT is a relatively low-stress, efficient test for memory in mice, and is appropriate for the detection of neuropsychological changes following pharmacological, biological, or genetic manipulations.

Physiological effects of a habituation procedure for functional MRI in awake mice using a cryogenic radiofrequency probe

BackgroundFunctional magnetic resonance imaging (fMRI) in mice is typically performed under anesthesia due to difficulties in holding the head of awake mice stably with a conventional three-point fixation method that uses a tooth-bar and earplugs. Although some studies have succeeded in fMRI in awake mice by attaching a head-post on the skull, this cannot be applied to fMRI using a high signal-to-noise ratio (SNR) cryogenic MRI-detector, CryoProbe, because it covers the head of a mouse closely. New methodWe developed head-fixation implements for awake mice that are applicable to fMRI using CryoProbe. ResultsA head-bar was surgically attached to the skull of a mouse that was then habituated to a mock fMRI-environment, two hours/day for eight days with physiological examinations of body-weight, fecal weight, electromyogram (EMG), and electrocardiogram. EMG power decreased with just one day of habituation, whereas heart rate decreased after at least seven days of habituation. Estimated head motions of awake mice during fMRI were significantly smaller than a voxel size. Unexpectedly, temporal SNR of fMRI signals for awake mice was higher than that for anesthetized mice held by a conventional method. Functional connectivity in the brain of both anesthetized and awake mice showed bilateral and unilateral networks. Comparison with existing method(s)fMRI using CryoProbe had been performed on anesthetized mice previously. Our method does not use anesthetics during habituation or fMRI. ConclusionOur method would be beneficial for translational research using fMRI in mice and humans because human fMRI is typically performed without anesthetics.

Day to day variability in fat oxidation and the effect after only 1 day of change in diet composition.

Indirect calorimetry is a common and noninvasive method to estimate rate of fat oxidation (FatOx) during exercise, and test-retest reliability should be considered when interpreting results. Diet also has an impact on FatOx. The aim of the present study was to investigate day to day variations in FatOx during moderate exercise given the same diet and 2 different isoenergetic diets. Nine healthy, moderately-trained females participated in the study. They performed 1 maximal oxygen uptake test and 4 FatOx tests. Habitual diets were recorded and repeated to assess day to day variability in FatOx. FatOx was also measured after 1 day of fat-rich (26.8% carbohydrates (CHO), 23.2% protein, 47.1% fat) and 1 day of CHO-rich diet (62.6% CHO, 20.1% protein, 12.4% fat). The reliability test revealed no differences in FatOx, respiratory exchange ratio (RER), oxygen uptake, carbon dioxide production, heart rate, blood lactate concentration, or blood glucose between the 2 habitual diet days. FatOx decreased after the CHO-rich diet compared with the habitual day 2 (from 0.42 ± 0.15 to 0.29 ± 0.13 g·min(-1), p < 0.05). No difference was found in FatOx between fat-rich diet and the 2 habitual diet days. FatOx was 31% lower (from 0.42 ± 0.14 to 0.29 ± 0.13 g·min(-1), p < 0.01) after the CHO-rich diet compared with the fat-rich diet. Using RER data to measure FatOx is a reliable method as long as the diet is strictly controlled. However, even a 1-day change in macronutrient composition will likely affect the FatOx results.

Evidences of the role of the rodent hippocampus in the non-spatial recognition memory

The hippocampus is a key region responsible for processing spatial information. However, the role of the hippocampus in non-spatial recognition memory is still controversial. In the present study, we performed hippocampal lesioning to address this controversy. The hippocampi of mice were disrupted with bilateral cytotoxic lesions, and standard object recognition (non-spatial) and object location recognition (spatial) were tested. In the habituation period, mice with hippocampal lesions needed a significantly longer time to fully habituate to the test box. Interestingly, after 4 days of habituation (insufficient habituation), the recognition index was similar in the sham and hippocampal lesion groups. However, exploration time was significantly shorter in mice with hippocampal lesions compared with that in control mice. Interestingly, if mice were subjected to a 10-days-long period of habituation (full habituation), the recognition index was significantly lower in mice with hippocampal lesions compared with that in control mice; however, total exploration time was similar in both groups. Furthermore, the object recognition test after full habituation occluded hippocampal long-term potentiation, a cellular model of memory. These results indicate that sufficient habituation is required to observe the effects of hippocampal lesions on object recognition memory.

Associations between longer habitual day napping and non-alcoholic fatty liver disease in an elderly Chinese population.

ContextBoth longer habitual day napping and Non-Alcoholic Fatty Liver Disease (NAFLD) are associated with diabetes and inflammation, but the association between day napping and NAFLD remains unexplored.ObjectiveTo investigate the association between the duration of habitual day napping and NAFLD in an elderly Chinese population and to gain insight into the role of inflammatory cytokines in this association.Design and SettingWe conducted a series of cross-sectional studies of the community population in Chongqing, China, from 2011 to 2012.ParticipantsAmong 6998 participants aged 40 to 75 years, 6438 eligible participants were included in the first study and analyzed to observe the association between day napping duration and NAFLD. In a separate study, 80 non-nappers and 90 nappers were selected to identify the role of inflammatory cytokines in this association. Logistic regression models were used to examine the odds ratios (ORs) of day nap duration with NAFLD.ResultsDay nappers had a significantly higher prevalence of NAFLD (P<0.001). Longer day napping duration was associated in a dose-dependent manner with NAFLD (P trend <0.001). After adjustment for potential confounders, the ORs were 1.67 (95% CI 1.13–2.46) for those reporting 0.5–1 h and 1.49 (95% CI 1.01–2.19) for those reporting >1 h of day napping compared with individuals who did not take day naps (all P<0.05). Longer-duration day nappers had higher levels of IL-6 and progranulin (PGRN) but lower levels of Secreted frizzled-related protein-5 (SFRP5, all P trend <0.001). After adjusting for IL-6, PGRN, and SFRP5, the association between day napping duration and NAFLD disappeared (all P>0.05).ConclusionLonger day napping duration is associated with a higher prevalence of NAFLD, and inflammatory cytokines may be an essential link between day napping and NAFLD.

Activation of microglia and astrocytes in the nucleus tractus solitarius during ventilatory acclimatization to 10% hypoxia in unanesthetized mice

Nucleus tractus solitarius (NTS) is the integrative sensory relay of autonomic functions in the brainstem. To explore the nonneuronal cellular basis of central chemosensitivity during the first 24 hr of ventilatory acclimatization to hypoxia (VHA), we have investigated glial activation markers in the NTS. Conscious mice (C57/BL6) were placed in a hermetic hypoxia chamber containing a plethysmograph to record ventilation. After 4 days of habituation to the normoxic environment, mice were subjected to physiological hypoxia (10% O2 ) for 1, 6, or 24 hr. To dissociate interactions between microglia and astrocytes, another group received daily minocycline, a microglia activation blocker. By immunochemical localization of astrocytes (GFAP), activated microglia (Cd11b), and total microglia (Iba-1), we identified an oxygen-sensing glial layer in the NTS, in which astrocytes are first activated after 1-6 hr of hypoxia, followed by microglia after 6-24 hr of hypoxia. Minocycline administration suppressed microglial activation and decreased astrocyte activation at 6 hr and VHA at 24 hr of hypoxia. These results suggest that astrocytes contribute to the neuronal response during the first hour of hypoxia, whereas microglial cells, via cross-talk with astrocytes, are involved in the VHA during the first 24 hr of acclimatization.

Reduction in Serum Bilirubin Concentration Following Administration of Crude Leaf Extract of Viscum album (Mistletoe) in High Salt Fed Rats

Aims: This study was designed to determine the effect of a high salt diet on serum bilirubin concentration and to ascertain the impact of treatment with Viscum album on same. Methodology: Twenty male albino wistar rats weighing 150 200g were used for this study. After seven days of habituation, the animals were randomly divided into four (4) groups of five rats each. Group 1 (NC) served as control and were fed with normal rat pellet and water; group 2(NT) served as the control treated group (administered 150 mg/kg Viscum album orally, in addition to rat pallet and water); group 3 (SF) served as the high salt diet fed group (without treatment), while group 4 (ST) served as the high salt diet fed group, treated orally with 150 mg/kg Viscum album. The feeding regimen lasted for six weeks, after which the animals were sacrificed and blood samples collected for analysis. Results: Mean serum total bilirubin concentration was significantly (p<0.001) higher in the SF group compared to control, NT and ST group. It was also significantly (p<0.001) lower Original Research Article British Journal of Pharmaceutical Research, 4(3): 352-361, 2014 353 in the ST group compared to SF group. Serum conjugated bilirubin concentration was significantly (p<0.001) increased in the SF group compared to NC, NT and ST group. It was also significantly (p<0.001) reduced in the ST group compared to the SF group. Serum unconjugated bilirubin concentration was significantly (p<0.001) increased in the SF group compared to NC, NT and ST group. Serum unconjugated bilirubin concentration was significantly (p<0.01) lower in the ST group compared to SF group. Conclusion: Our results are indicative of the fact that oral administration of Viscum album reduces serum bilirubin concentration in high salt fed animals.