The mechanisms of GABAergic signalling in the peripheral pain pathway

Peripheral pain pathway plays a crucial role in how pain is perceived and felt. The dorsal root ganglia (DRG) which house the primary sensory neurons have become the focus of many emerging pain studies due to its potential as a functional structure in controlling pain transmission, and not only for producing proteins and providing nutrients essential for neuron survival. The major inhibitory neurotransmitter in the nervous system, GABA has been shown to play a significant role in this regard. Within the present study, the mechanism of GABA release within DRG neurons was investigated by studying the expression of vesicular GABA transporter (VGAT) in the DRG neurons. VGAT was highly expressed in the DRG neuron somata. The VGAT-positive neurons also expressed markers of subpopulations of DRG neurons, including those involved in nociception. The availability of VGAT luminal (VGAT-C) and cytoplasmic (VGAT-N) domains were utilised to investigate the mechanism of GABA release in a live DRG neuron culture. This mechanism involves the recycling process of vesicles following their exocytosis. Imaging of the internalization of VGAT-C domain during vesicle recycling indicates GABA is released via exocytosis and has both, tonic and activity-dependent components. Using the in vivo electrophysiological recordings, neuronal firing in the spinal nerve and dorsal branches of the peripheral nerve (before and after the DRG, respectively), was investigated. These data revealed existence of a ‘filter’ in the DRG that decreased the frequency of the neuronal firing passing through the DRG. This filtering effect was overcome by bicuculline, a GABAA receptor antagonist indicating the role of GABAA receptor in peripheral pain pathway. This role of GABAA receptor was also supported by the decrease in GABAA receptor activation in the presence of bicuculline in DRG neurons co-cultured with HEK293 cells. In sum, in the DRG, GABA is liberated into the interneuronal space via Ca2+-dependent vesicular exocytosis, which in turn acts on GABAA receptors. This GABAergic signalling is responsible for filtering the action potentials from the periphery to the central terminals in the spinal cord. These findings identify and further characterize peripheral ‘gate’ within the somatosensory system

BoneMicro-CT Assessments in an Orchidectomised RatModel Supplemented with Eurycoma longifolia

Recent studies suggested that Eurycoma longifolia, a herbal plant, may have the potential to treat osteoporosis in elderly male. This study aimed to determine the effects of Eurycoma longifolia supplementation on the trabecular bone microarchitecture of orchidectomised rats (androgen-deficient osteoporosis model). Forty-eight-aged (10–12 months old) Sprague Dawley rats were divided into six groups of sham-operated (SHAM), orchidectomised control (ORX), orchidectomised + 7mg/rat testosterone enanthate (TEN) and orchidectomised + Eurycoma longifolia 30 mg/kg (EL30), orchidectomised + Eurycoma longifolia 60 mg/kg (EL60), orchidectomised + Eurycoma longifolia 90 mg/kg (EL90). Rats were euthanized following six weeks of treatment. The\ud left femora were used to measure the trabecular bone microarchitecture using micro-CT. Orchidectomy significantly decreased connectivity density, trabecular bone volume, and trabecular number compared to the SHAM group. Testosterone replacement reversed all the orchidectomy-induced changes in the micro-CT parameters. EL at 30 and 60 mg/kg rat worsened the trabecular bone connectivity density and trabecular separation parameters of orchidectomised rats. EL at 90 mg/kg rat preserved the bone volume. High dose of EL (90 mg/kg) may have potential in preserving the bone microarchitecture of orchidectomised rats, but lower doses may further worsen the osteoporotic changes

Water balance: case study of a constructed wetland as part of the bio-ecological drainage system (BIOECODS)

The Bio-ecological Drainage System, or BIOECODS, is an urban drainage system located at the Engineering Campus, Universiti Sains Malaysia. It consists of a constructed wetland as a part of the urban drainage system to carry storm water in a closed system. In this closed system, the constructed wetland was designed particularly for further treatment of storm water. For the purpose of studying the water balance of the constructed wetland, data collection was carrie

Are Visitors Satisfied and Intend to Revisit Rumah Terbuka Aidilfitri?: Malaysian Community in Perak

AbstractThis study empirically examined the level of visitors’ satisfaction and intention to revisit the Rumah Terbuka Aidilfitri celebration in Perak, Malaysia. 160 visitors were given questionnaires during the festival. The event managed to attract a huge crowd from different ethnicities and backgrounds. Varieties of foods were served to the visitors. However, they have to spend time queuing for food and sometimes could stretch into long hours before they can be seated and enjoy the festivals. Nevertheless, majority of the respondents satisfied with the festival and would return to this festival again and will recommend the festival to others

A Review of Product Knowledge and Determinants of Consumer Purchase Intention on Plant-Based Meat Products In Malaysia

Chronic diseases caused by poor health choices have been identified as a significant contributor to mortality. The poor dietary intake of Malaysians including high consumption of meat and other animal-based products may contribute to development of non-communicable diseases, such as obesity, hypertension, diabetes, and cancer. The amount of meat eaten by Malaysians per person has increased to more than 55 kg a year in 2019, and obviously, a transition towards plant-based diets is urgently needed. Nevertheless, product knowledge and determinants of consumer purchase intention of plant-based meat need to be explored further for Malaysians to effectively adopt a healthy diet. Keywords: Consumers; Purchase Intention; Plant-Based Meat; Malaysia eISSN: 2398-4287 © 2023. The Authors. Published for AMER and cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under the responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), and cE-Bs (Centre for Environment-Behaviour Studies), College of Built Environment, Universiti Teknologi MARA, Malaysia DOI: https://doi.org/10.21834/e-bpj.v8iSI15.510

Determination of intervention to improve food allergy knowledge among Malaysians

The population of food allergy sufferer world wide keep on increasing especially among children. Therefore, while the parent is working, this children is taken care by the nursery employees. Since there is no cure for food allergy, the nursery employees need to be knowledgeable to provide safe food and environment to them. For that reason, this study aims to determine the types of intervention that can help the nursery employees to improve their knowledge. This study is crucial to create awareness and protect this susceptible population to stay healty

Augmented reality (AR) and virtual reality (VR) applications during Covid-19 pandemic among preclinical medical and dentistry students: a mini-review

The efficacy of online learning in delivering theoretical knowledge with appropriate content to students is imperative, especially in the Covid-19 pandemic era. Substantial interactive teaching materials were developed for higher education. However, some were designed immensely general, especially in fulfilling the syllabus of preclinical medical and dentistry students. Augmented reality (AR) is an interactive three-dimension (3D) experience that uses computers to overlay virtual information in the real world whereas virtual reality (VR) is a computer-generated artificial recreation of a real-life experience or situation. Interestingly, both can be complemented and integrated into online and traditional teaching methods. Implementation of these technologies will increase the learning efficacy in understanding the human body’s anatomical and physiological changes in the normal or pathological state. As AR and VR technologies are continuously evolving, this review provides the preview and current updates on AR and VR applications in medical and dentistry education which may benefit the educators within these specialities

Local GABAergic signaling within sensory ganglia controls peripheral nociceptive transmission

The integration of somatosensory information is generally assumed to be a function of the central nervous system (CNS). Here we describe fully functional GABAergic communication within rodent peripheral sensory ganglia and show that it can modulate transmission of pain-related signals from the peripheral sensory nerves to the CNS. We found that sensory neurons express major proteins necessary for GABA synthesis and release and that sensory neurons released GABA in response to depolarization. In vivo focal infusion of GABA or GABA reuptake inhibitor to sensory ganglia dramatically reduced acute peripherally induced nociception and alleviated neuropathic and inflammatory pain. In addition, focal application of GABA receptor antagonists to sensory ganglia triggered or exacerbated peripherally induced nociception. We also demonstrated that chemogenetic or optogenetic depolarization of GABAergic dorsal root ganglion neurons in vivo reduced acute and chronic peripherally induced nociception. Mechanistically, GABA depolarized the majority of sensory neuron somata, yet produced a net inhibitory effect on the nociceptive transmission due to the filtering effect at nociceptive fiber T-junctions. Our findings indicate that peripheral somatosensory ganglia represent a hitherto underappreciated site of somatosensory signal integration and offer a potential target for therapeutic intervention

Application of neurotransmitters and dental stem cells for pulp regeneration: A review

Introduction: Although there have been many studies on stem cells, few have investigated how neurotransmitters and stem cell proliferation interact to regenerate dental pulp. Dental pulp regeneration is an innovative procedure for reviving dental pulp, if feasible for the entire tooth. Upon tooth injury, activated platelets release serotonin and dopamine in bulk to mobilize dental pulp stem cells to mediate natural dental repair. This has induced research on the role of neurotransmitters in increasing the proliferation rate of stem cells. This review also covers prospective future treatments for dental pulp regeneration. Methods: A literature search was performed via PubMed and ScienceDirect from 2001 to 2022, using the keywords “neurotransmitter,” “stem cell,” “tooth regeneration,” “tooth repair,” “regenerative dentistry,” and “dental pulp.” Different inclusion/exclusion criteria were used, and the search was restricted to English articles. Results: Nine publications reporting neurotransmitter interactions with stem cells for tooth and pulp regeneration were selected. Conclusion: Neurotransmitters were found to interact with dental stem cells. Evidence pointing to neurotransmitters as a factor in the increased proliferation of stem cells was found. This review thus gives hope for tooth pulp regeneration and repair