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@#Introduction: Studies show that adolescents are more reward sensitive compared to other age groups. The nucleus accumbens (NAcc) has been identified as a key brain area involved in reward through its connectivity to other reward-related brain areas. Our study aimed to characterise the white matter structural connectivity of nucleus accumbens with brain areas that are most often associated with reward in female adolescents. Methods: Fifteen healthy female Malay adolescents were recruited and underwent diffusion-weighted brain scanning. Two behaviour scales were also given to verify typical reward responsiveness. Then, probabilistic tractography and NAcc segmentation were performed on the data using FMRIB Software Library (FSL). Probabilistic tractography was performed to determine the relative connection probability of nucleus accumbens (NAcc) to areas shown to be associated with reward, namely amygdala, anterior cingulate cortex (ACC), medial orbitofrontal cortex (mOFC), hippocampus, ventrolateral prefrontal cortex (vlPFC) and dorsolateral prefrontal cortex (dlPFC). Connectivity-based segmentation of NAcc was performed to determine the spatial distribution of its connectivity with the target brain areas according to the highest connection probability. Results: The highest relative connection probability was found between NAcc to mOFC, while the NAcc parcellation showed the widest distribution of connection to mOFC compared to the other five targets on both sides of the brain. Conclusion: Our findings demonstrated the strongest structural connectivity and widest distribution between NAcc and mOFC compared with other brain areas related to reward. This study’s findings could be used as baseline to compare with people with atypical reward circuit problems.
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@#Introduction: Minocycline has been demonstrated to have potent effects on neurologic structures and functions in several animal models. However, its neuroprotective properties following a single injection of lipopolysaccharide (LPS) in an adult rat model have not been clearly elucidated. This study investigated minocycline’s neuroprotective effects in the LPS-induced neuroinflammation rat model. Methods: Fifty adult male Sprague Dawley rats were split into five groups at random: (i) control, (ii) distilled water-treated LPS, (iii) 25 mg/kg minocycline-treated LPS, (iv) 50 mg/kg minocycline-treated LPS, and (v) 10 mg/kg memantine-treated LPS. On day 5, LPS (5 mg/kg) was given intraperitoneally once, whereas minocycline and memantine were given once daily for 14 days. Results: LPS was found to significantly induce β-amyloid peptide deposition and neuronal damage, and impair recognition memory, while administration of minocycline dose-dependently reversed these effects. These data suggest that LPS-induced recognition memory impairment by inducing β-amyloid peptide deposition and neuronal damage in the cortical and hippocampal areas. Furthermore, we compared minocycline with memantine administration, and these data suggested better effects in minocycline (50 mg/kg) and comparable effects between minocycline (25 mg/kg) and memantine (10 mg/kg) treatments in reducing β-amyloid peptide deposition, neuronal damage and recognition memory impairment induced by LPS. Conclusion: Minocycline may be a strong contender as an effective preventive-therapeutic drug for neuroinflammatory diseases such as Alzheimer’s disease (AD) based on these findings.
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@#Introduction: Increased nociceptive responses were shown in the offspring of prenatally stressed rats. Reports have demonstrated the anti-nociceptive effects of Tualang honey in the rat offspring. The present study was done to determine whether the modulation of nociceptive behaviour by Tualang honey was mediated by modulating changes in the histology, oxidative stress parameters and N-methyl-D-aspartate (NMDA) receptors in the thalamus of the rat offspring. Methods: Eighteen Sprague Dawley pregnant rats were randomly assigned to control (C), stress (S) and stress-treated with Tualang honey (SH) groups. Stress was given in a form of restraint stress.Tualang honey was given to SH group from first day of pregnancy until delivery. Thirty-three adult male offspring were subjected to formalin test before they were sacrificed. Nociceptive behaviour score, number of neurons, level of oxidative stress parameters and NMDA receptors in the thalamus were analysed by using one-way ANOVA. Results: The study demonstrated a significant decrease in mean nociceptive behaviour score (p<0.05) with lower malondialdehyde (MDA, p<0.05) and higher superoxide dismutase SOD and catalase levels in the thalamus of SH group compared to S group (p<0.05). There was also increased Nissl positive neurons in the thalamus of SH group compared to S group. There was no significant difference in NMDA receptor level between S and SH groups. Conclusion: The modulation of nociceptive responses in the prenatally stressed rat offspring by Tualang honey was associated with improvement in oxidative stress parameters and histology of the thalamus in the rat offspring exposed to prenatal stress.
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OBJECTIVE@#This study was done to determine whether Tualang honey could prevent the altered nociceptive behaviour, with its associated changes of oxidative stress markers and morphology of the spinal cord, among the offspring of prenatally stressed rats.@*METHODS@#Pregnant rats were divided into three groups: control, stress, and stress treated with Tualang honey. The stress and stress treated with Tualang honey groups were subjected to restraint stress from day 11 of pregnancy until delivery. Ten week old male offspring (n = 9 from each group) were given formalin injection and their nociceptive behaviours were recorded. After 2 h, the rats were sacrificed, and their spinal cords were removed to assess oxidative stress activity and morphology. Nociceptive behaviour was analysed using repeated measures analysis of variance (ANOVA), while the levels of oxidative stress parameters and number of Nissl-stained neurons were analysed using a one-way ANOVA.@*RESULTS@#This study demonstrated that prenatal stress was associated with increased nociceptive behaviour, changes in the oxidative stress parameters and morphology of the spinal cord of offspring exposed to prenatal stress; administration of Tualang honey reduced the alteration of these parameters.@*CONCLUSION@#This study provides a preliminary understanding of the beneficial effects of Tualang honey against the changes in oxidative stress and neuronal damage in the spinal cord of the offspring of prenatally stressed rats.
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Objectives: Overweight and obesity are known to cause various patterns of alteration to the pulmonary function test [PFT] parameters. We sought to investigate gender differences in PFT parameters and examine the relationship between body mass index [BMI] and PFT parameters
Methods: We conducted a retrospective study of 126 patients referred for a PFT by various medical specialties between January and December 2015. PFT was measured using spirometry, and BMI was calculated using Quetelet's index
Results: Female patients exhibited lower mean values for all PFT parameters compared to male patients. The forced vital capacity [FVC] % predicted was less than 80% for all patients while the ratio of forced expiratory volume in 1 second [FEV1]/FVC was higher with increased BMI. BMI was positively correlated with peak expiratory flow in all patients, and with FEV1/FVC ratio in males but not in females
Conclusions: In our studied population, males exhibited higher mean values of PFT parameters than females. Increased BMI may be associated with a restrictive pattern on spirometry
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Stress modulates pain perception, resulting in either stress-induced analgesia or stress-induced hyperalgesia, as reported in both animal and human studies. The responses to stress include neural, endocrine, and behavioural changes, and built-in coping strategies are in place to address stressors. Peculiar to humans are additional factors that modulate pain that are experienced in times of stress, notably psychological factors that potentially influence the directionality of pain perception.
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Background: Depression is one of the common post-menopausal symptoms. In addition to estrogen deficiency, social instability stress may contribute as an additional underlying factor in the development of depressive behaviour in females. Therefore, this study was aimed at examining the influence of social instability stress on depressive behaviour in ovariectomized rats. Methods: The rats were divided into four groups (n = 5 per group); (i) sham-operated control without stress, (ii) sham-operated control with stress, (iii) ovariectomized without stress, and (iv) ovariectomized with stress. These rats were subjected to social instability stress procedures for 15 days prior to an enforced swimming test. Struggling, immobility, and swimming times were recorded promptly. Results: The results were analysed using the one-way analysis of variance (ANOVA) and a P value of < 0.05 was considered as significant. The mean durations of struggling, immobility, and swimming behaviour were significantly distinct among the four groups. Ovariectomized rats exhibited a substantial decrease in struggling and swimming behaviour, and an increase in immobility behaviour in comparison with the sham-operated controls (P < 0.05). Ovariectomized rats with stress displayed a supplementary decrease in struggling and swimming behaviour as well as an advanced increase in immobility behaviour, compared to sham-operated controls with or without stress (P < 0.05). Conclusion: In summary, these findings suggest that ovariectomized rats encountered an augmented amount of depressive behaviour following social instability stress.