• Development and Reproduction
• /
• v.19 no.4
• /
• pp.167-180
• /
• 2015

Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.13 no.1
• /
• pp.46-49
• /
• 2015

Carbon monoxide (CO) intoxication is a leading cause of severe neuropsychological impairments. Peripheral nerve injury has rarely been reported. Following are brief statements describing the motor peripheral neuropathy involved bilateral lower extremities of a patient who recovered following acute carbon monoxide poisoning. After inhalation of smoke from a fire, a 60-year-old woman experienced bilateral leg weakness without edema or injury. Neurological examination showed diplegia and deep tendon areflexia in lower limbs. There was no sensory deficit in lower extremities, and no cognitive disturbances were detected. Creatine kinase was normal. Electroneuromyogram patterns were compatible with the diagnosis of bilateral axonal injury. Clinical course after normobaric oxygen and rehabilitation therapy was marked by complete recovery of neurological disorders. Peripheral neuropathy is an unusual complication of CO intoxication. Motor peripheral neuropathy involvement of bilateral lower extremities is exceptional. Various mechanisms have been implicated, including nerve compression secondary to rhabdomyolysis, nerve ischemia due to hypoxia, and direct nerve toxicity of carbon monoxide. Prognosis is commonly excellent without sequelae. Emergency physicians should understand the possible-neurologic presentations of CO intoxication and make a proper decision regarding treatment.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.31 no.3
• /
• pp.105-120
• /
• 2020

Although autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social impairments, patients with ASD frequently manifest atypical sensory behaviors. Recently, atypical sensory perception in ASD has received much attention, yet little is known about its cause or neurobiology. Herein, we review the findings from neuroimaging studies related to visual perception in ASD. Specifically, we examined the neural underpinnings of visual detection, motion perception, and face processing in ASD. Results from neuroimaging studies indicate that atypical visual perception in ASD may be influenced by attention or higher order cognitive mechanisms, and atypical face perception may be affected by disrupted social brain network. However, there is considerable evidence for atypical early visual processing in ASD. It is likely that visual perceptual abnormalities are independent of deficits of social functions or cognition. Importantly, atypical visual perception in ASD may enhance difficulties in dealing with complex and subtle social stimuli, or improve outstanding abilities in certain fields in individuals with Savant syndrome. Thus, future research is required to elucidate the characteristics and neurobiology of autistic visual perception to effectively apply these findings in the interventions of ASD.

• Journal of Communications and Networks
• /
• v.18 no.3
• /
• pp.411-419
• /
• 2016

This article investigates the problem of distributed channel selection in opportunistic spectrum access networks from a perspective of interference minimization. The traditional physical (PHY)-layer interference model is for information theoretic analysis. When practical multiple access mechanisms are considered, the recently developed binary medium access control (MAC)-layer interference model in the previous work is more useful, in which the experienced interference of a user is defined as the number of competing users. However, the binary model is not accurate in mathematics analysis with poor achievable performance. Therefore, we propose a real-valued one called stochastic MAC-layer interference model, where the utility of a player is defined as a function of the aggregate weight of the stochastic interference of competing neighbors. Then, the distributed channel selection problem in the stochastic MAC-layer interference model is formulated as a weighted stochastic MAC-layer interference minimization game and we proved that the game is an exact potential game which exists one pure strategy Nash equilibrium point at least. By using the proposed stochastic learning-automata based uncoupled algorithm with heterogeneous learning parameter (SLA-H), we can achieve suboptimal convergence averagely and this result can be verified in the simulation. Moreover, the simulated results also prove that the proposed stochastic model can achieve higher throughput performance and faster convergence behavior than the binary one.

• Molecules and Cells
• /
• v.23 no.3
• /
• pp.259-271
• /
• 2007

Investigation of molecular and cellular mechanisms of synaptic plasticity is the major focus of many neuroscientists. There are two major reasons for searching new genes and molecules contributing to central plasticity: first, it provides basic neural mechanism for learning and memory, a key function of the brain; second, it provides new targets for treating brain-related disease. Long-term potentiation (LTP), mostly intensely studies in the hippocampus and amygdala, is proposed to be a cellular model for learning and memory. Although it remains difficult to understand the roles of LTP in hippocampus-related memory, a role of LTP in fear, a simplified form of memory, has been established. Here, I will review recent cellular studies of LTP in the anterior cingulate cortex (ACC) and then compare studies in vivo and in vitro LTP by genetic/pharmacological approaches. I propose that ACC LTP may serve as a cellular model for studying central sensitization that related to chronic pain, as well as pain-related cognitive emotional disorders. Understanding signaling pathways related to ACC LTP may help us to identify novel drug target for various mental disorders.

• Journal of Internet Computing and Services
• /
• v.13 no.4
• /
• pp.73-82
• /
• 2012

The worldwide increase of cognitive surplus leads to successful social authoring projects. In this research, social authoring mechanisms used in Linux and Wikipedia projects were analyzed to identify the key success factors. In addition, tools used in the recent successful social media such as Facebook and Ushahidi were evaluated to extract components which may be applied in social authoring systems. Based on these analyses, the improvement factors in the design of social authoring projects were suggested. The social authoring projects are expected to be more successfully achieved by providing the core components proposed in this article.

• Journal of mucopolysaccharidosis and rare diseases
• /
• v.3 no.2
• /
• pp.41-43
• /
• 2017

Prader-Willi syndrome (PWS) is a genetic disorder that is considered, especially on child, to cause poor feeding, hypotonia, failure to thrive, developmental delay and hypogonadism which is known to affect between 1 in 10,000 and 30,000 people. The children with PWS are viewed as affected by growth hormone (GH) insufficiency, although the exact mechanisms of GH deficiency are not fully understood. However, the benefits of GH treatment in children with PWS are well established. Myers, et al. (2006), Grugni, et al. (2016) indicated its positive effects on linear growth, body composition, motor function, respiratory function and psychomotor development. Despite of its effectiveness and advantages had been well known and proven in many other studies, there is only one recombinant GH product that is approved for PWS in Korea, $Genotropin^{(R)}$, till now. A phase III clinical study of GH treatment with $Eutropin^{TM}$, in 34 Korean PWS children is in progress, which is expected to have comparable effects and safety profile with the active control by assessing auxological changes such as height standard deviation score, body composition changes such as lean body mass and percent body fat, motor and cognitive development using Bayley scale, and safety profiles.

• Journal of TMJ Balancing Medicine
• /
• v.8 no.1
• /
• pp.11-15
• /
• 2018

Recently, clinical efficacies of the intraoral balancing appliance therapy have been reported by several researchers, and it has been found that there are various kinds of diseases that can be effectively applied. However, studies on cerebrovascular disease, one of the main diseases with a high mortality rate, are still poorly reported, and studies of temporomandibular joint disorder (TMD)-induced changes in brain function suggest that cerebrovascular disease is more appropriate as an adaptive disorder of the temporomandibular joint (TMJ) balancing device. In the developed countries, the importance of research on the structure and function of the brain has been recognized and spurred on the related research. In Korea, the research on brain function and cognitive disorders should have promoted more massively. In order to regain its former reputation in the Korean medicine in the field of cerebrovascular disease, it should be spurred on basic research and clinical case studies. In addition, extensive and in-depth studies including animal studies are needed to establish the basis of underlying mechanisms of the TMJ balancing therapies.

• International Journal of Computer Science & Network Security
• /
• v.23 no.2
• /
• pp.47-54
• /
• 2023

This article reviews recent advances and perspectives in neuroscience related to consciousness, cognition, and neural networks in the brain. The neural mechanisms underlying cognitive processes, such as perception, attention, memory, and decision-making, are explored. The article also examines how these processes give rise to our experience of consciousness. The implications of these findings for our understanding of the brain and its functions are presented, as well as potential applications of this knowledge in fields such as medicine, psychology, and artificial intelligence. Additionally, the article explores the concept of a quantum viewpoint concerning consciousness, cognition, and creativity and how incorporating DNA as a key element could reconcile classical and quantum perspectives on human behaviour, consciousness, and cognition, as explained by genomic psychological theory. Furthermore, the article explains how the human brain processes external stimuli through the sensory nervous system and how it can be simulated using an artificial neural network (ANN) consisting of one input layer, multiple hidden layers, and an output layer. The law of learning is also discussed, explaining how ANNs work and how the modification of weight values affects the output and input values. The article concludes with a discussion of future research directions in this field, highlighting the potential for further discoveries and advancements in our understanding of the brain and its functions.

• Biomolecules & Therapeutics
• /
• v.31 no.2
• /
• pp.148-160
• /
• 2023

Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.