A FRAMEWORK FOR CHARACTERIZING REGIONAL ALTERATIONS IN DOPAMINE NEUROTRANSMISSION IN THE CONTEXT OF DRUGS AND DISEASE USING FAST-SCAN CYCLIC VOLTAMMETRY

Dopamine (DA) has become a sort of buzzword as the ‘pleasure’ neurotransmitter that signals for natural rewards, but is ‘hijacked’ by drugs of abuse and the instant gratification we derive from our phones, Facebook, and fast-food diets in the fast-paced world we live in. In reality, DA has much more nuanced and varied functions that include the regulation of attention, working memory, motivation, movement, and even endocrine functions, which largely depends upon the region DA is acting in the brain. Dysfunction of DA neurotransmission is implicated in conditions like Parkinson’s disease (PD), attention deficit/hyperactivity disorder (ADHD), drug addiction, and traumatic brain injury (TBI) to name just a few. As such, the DAergic system represents a rational pharmaceutical target that act as DA receptor agonists, antagonists, indirect agonists, and DA reuptake inhibitors. Understanding how region-specific DA neurotransmission is altered in pathological states and following both acute and chronic drug administration, requires multi-faceted research approaches but can be significantly driven by advancements in research methodologies. It is for this reason that we hope readers will find the work contained herein particularly timely and important. Although the work contained here represents research conducted using fast-scan cyclic voltammetry (FSCV), an electrochemical method to monitor in vivo electrically stimulated DA neurotransmission that has been around since the mid 1980s, we describe the development of a novel quantitative interpretive framework for FSCV data that enhances the ability to characterize the region-specific DA neurotransmission in the context of drugs and diseases. To illustrate the utility of our framework, we demonstrate how our approach has been used to resolve the mechanistic actions of the most commonly used Parkinsonian drug, L-DOPA, on regiospecific DA neurotransmission. Moreover, our framework was utilized to characterize the regiospecific DAergic dysfunction following an experimental model of TBI and the robust neurorestorative effects of chronic methylphenidate treatment in this model. To this end, we not only describe a theoretical framework for characterizing regiospecific alterations in DA neurotransmission, but we also offer practical examples that may serve as a roadmap for studying DA neurotransmission kinetics in the context of drugs and other diseases

Socio-Economic Characteristics and Fishing Operation Activities of the Artisanal Fishers in the Sundarbans Mangrove Forest, Bangladesh

The Sundarbans Mangrove Forest (SMF) is a complex ecosystem containing the most diverse and abundant natural resources of Bangladesh. The research was designed to investigate the socio-economic characteristics and fishing operation activities of the artisanal fishers in the SMF through case studies. Despite the great importance of mangroves in the livelihood of the artisanal fishermen in the SMF, deforestation is perceived to continue due to illegal logging and deterioration of mangroves for climate change, increased salinity, natural disasters, shrimp farming and household consumption. The consequences are depleted fish and fishery resources, changes in fisher's primary occupation and livelihood status. The present study also elicited several risks and shocks of the fishermen livelihood like the attack by dacoits, hostage, ransom, and attack by tigers, natural disasters, river bank erosion. However, the artisanal fishermen adopted different strategies to cope with the changing conditions by forming associations, violating the fisheries laws and regulations, migrating, sharing responsibilities with the household members, and transmitting local ecological knowledge. This study concludes that there is an urgency to update the existing policies and management issues for the sustainable extraction of the SMF resources for the improvement of the artisanal fishermen livelihood.Peer reviewe

Flexibility of Timescales of Evidence Evaluation for Decision Making

To understand the neural mechanisms that support decision making, it is critical to characterize the timescale of evidence evaluation. Recent work has shown that subjects can adaptively adjust the timescale of evidence evaluation across blocks of trials depending on context [1]. However, it's currently unknown if adjustments to evidence evaluation occur online during deliberations based on a single stream of evidence. To examine this question, we employed a change-detection task in which subjects report their level of confidence in judging whether there has been a change in a stochastic auditory stimulus. Using a combination of psychophysical reverse correlation analyses and single-trial behavioral modeling, we compared the time period over which sensory information has leverage on detection report choices versus confidence. We demonstrate that the length of this period differs on separate sets of trials based on what's being reported. Surprisingly, confidence judgments on trials with no detection report are influenced by evidence occurring earlier than the time period of influence for detection reports. Our findings call into question models of decision formation involving static parameters that yield a singular timescale of evidence evaluation and instead suggest that the brain represents and utilizes multiple timescales of evidence evaluation during deliberation

Timescales of Evidence Evaluation for Decision Making and Associated Confidence Judgments Are Adapted to Task Demands.

Decision making often involves choosing actions based on relevant evidence. This can benefit from focussing evidence evaluation on the timescale of greatest relevance based on the situation. Here, we use an auditory change detection task to determine how people adjust their timescale of evidence evaluation depending on task demands for detecting changes in their environment and assessing their internal confidence in those decisions. We confirm previous results that people adopt shorter timescales of evidence evaluation for detecting changes in contexts with shorter signal durations, while bolstering those results with model-free analyses not previously used and extending the results to the auditory domain. We also extend these results to show that in contexts with shorter signal durations, people also adopt correspondingly shorter timescales of evidence evaluation for assessing confidence in their decision about detecting a change. These results provide important insights into adaptability and flexible control of evidence evaluation for decision making

Timescales of Evidence Evaluation for Decision Making and Associated Confidence Judgments Are Adapted to Task Demands.

Decision making often involves choosing actions based on relevant evidence. This can benefit from focussing evidence evaluation on the timescale of greatest relevance based on the situation. Here, we use an auditory change detection task to determine how people adjust their timescale of evidence evaluation depending on task demands for detecting changes in their environment and assessing their internal confidence in those decisions. We confirm previous results that people adopt shorter timescales of evidence evaluation for detecting changes in contexts with shorter signal durations, while bolstering those results with model-free analyses not previously used and extending the results to the auditory domain. We also extend these results to show that in contexts with shorter signal durations, people also adopt correspondingly shorter timescales of evidence evaluation for assessing confidence in their decision about detecting a change. These results provide important insights into adaptability and flexible control of evidence evaluation for decision making

Assemblage structure of nektonic fauna in the Meghna estuary of Bangladesh: relationship with environmental variables

1401-1409In this study, the assemblage structure of nektonic fauna were studied in relation to some important environmental variables in the Meghna Estuary, the largest estuarine ecosystem of Bangladesh. Silica, nitrite, phosphate, and total suspended solids (TSS) were found to be positively correlated with fish species abundance. Nitrite and TSS showed significant difference, and water pH, salinity, transparency, water temperature, and dissolved oxygen were found to be negatively correlated. The results of similarity analysis showed a significant difference between different sampling stations and seasons, and revealed that finfish species like Trypauchen vagina, Polynemus paradiseus, Johnius dussumieri, Harpodon nehereus contributed significantly (>10.0%) to the fish abundance structure of each sampling station. Cluster analysis shows 53% similarity level in the abundance of fish in different seasons and sampling stations. Significant effect of water transparency and salinity was observed through Canonical Correspondence Analysis (CCA) in shaping assemblage structure and species distribution

Stem Cell Transplantation Therapy and Neurological Disorders: Current Status and Future Perspectives

Neurodegenerative diseases are a global health issue with inadequate therapeutic options and an inability to restore the damaged nervous system. With advances in technology, health scientists continue to identify new approaches to the treatment of neurodegenerative diseases. Lost or injured neurons and glial cells can lead to the development of several neurological diseases, including Parkinson’s disease, stroke, and multiple sclerosis. In recent years, neurons and glial cells have successfully been generated from stem cells in the laboratory utilizing cell culture technologies, fueling efforts to develop stem cell-based transplantation therapies for human patients. When a stem cell divides, each new cell has the potential to either remain a stem cell or differentiate into a germ cell with specialized characteristics, such as muscle cells, red blood cells, or brain cells. Although several obstacles remain before stem cells can be used for clinical applications, including some potential disadvantages that must be overcome, this cellular development represents a potential pathway through which patients may eventually achieve the ability to live more normal lives. In this review, we summarize the stem cell-based therapies that have been explored for various neurological disorders, discuss the potential advantages and drawbacks of these therapies, and examine future directions for this field