Functionally Assessing the Age-Related Decline in the Detection Rate of Photons by Cone Photoreceptors

Age-related decline in visual perception is usually attributed to optical factors of the eye and neural factors. However, the detection of light by cones converting light into neural signals is a crucial intermediate processing step of vision. Interestingly, a novel functional approach can evaluate many aspects of the visual system including the detection of photons by cones. This approach was used to investigate the underlying cause of age-related visual decline and found that the detection rate of cones was considerably affected with healthy aging. This functional test enabling to evaluate the detection of photons by cones could be particularly useful to screen for retinal pathologies affecting cones such as age-related macular degeneration. However, the paradigm used to functionally measure the detection of photons was complex as it was evaluating many other properties of the visual system. The aim of the current mini review is to clarify the underlying rationale of functionally evaluating the detection of photons by cones, describe a simpler approach to evaluate it, and review the impact of aging on the detection rate of cones.

The Etiology of Auditory Hallucinations in Schizophrenia: From Multidimensional Levels

Enormous efforts have been made to unveil the etiology of auditory hallucinations (AHs), and multiple genetic and neural factors have already been shown to have their own roles. Previous studies have shown that AHs in schizophrenia vary from those in other disorders, suggesting that they have unique features and possibly distinguishable mechanisms worthy of further investigation. In this review, we intend to offer a comprehensive summary of current findings related to AHs in schizophrenia from aspects of genetics and transcriptome, neurophysiology (neurometabolic and electroencephalogram studies), and neuroimaging (structural and functional magnetic resonance imaging studies and transcriptome–neuroimaging association study). Main findings include gene polymorphisms, glutamate level change, electroencephalographic alterations, and abnormalities of white matter fasciculi, cortical structure, and cerebral activities, especially in multiple regions, including auditory and language networks. More solid and comparable research is needed to replicate and integrate ongoing findings from multidimensional levels.

The Nature of Finger Enslaving: New Results and Their Implications

We present a review on the phenomenon of unintentional finger action seen when other fingers of the hand act intentionally. This phenomenon (enslaving) has been viewed as a consequence of both peripheral (e.g., connective tissue links and multifinger muscles) and neural (e.g., projections of corticospinal pathways) factors. Recent studies have shown relatively large and fast drifts in enslaving toward higher magnitudes, which are not perceived by subjects. These and other results emphasize the defining role of neural factors in enslaving. We analyze enslaving within the framework of the theory of motor control with spatial referent coordinates. This analysis suggests that unintentional finger force changes result from drifts of referent coordinates, possibly reflecting the spread of cortical excitation.

On Being Mortal

This chapter introduces readers to the basics of what they need to know about social psychology—that is, the study of how people’s feelings, ideas, and behaviors are influenced by the presence of others. It also looks at the increasingly important bio/neural factors such as genes, brain structure, and hormonal processes that are now being examined and understood as relevant to any study of human behavior, including group conflicts. In addition, it provides a brief introduction to the various methodologies that are increasingly able to measure social behavior, such as functional magnetic resonance imaging, electroencephalography, DNA analysis, and hormonal testing.

AN ANALYSIS OF THE EFFECT OF AEROBIC EXERCISE VERSUS YOGA IN YOUNG ADULTS ON PARAMETERS OF HEART RATE VARIABILITY (HRV)

Background: Neural factors such as temperature, hormones, etc. are regulated by cardiovascular functions, in which neural factors mainly affect the autonomic-nervous system (ANS), which plays a major role in the maintenance & regulation of cardiac functions. Aims & Objectives: To analyze of the effect of aerobic exercise versus yoga in young adults on parameters of heart rate variability (HRV) Methodology: This was a cross-sectional study carried out in a physiology department of a medical college over the six month span in which male & female adults with written & informed consent were involved in the study, so 70 volunteers were enrolled in the Yoga Group (Group A) & 70 volunteers in the Aerobic Exercise Group (Group B) during the six months period. Both of them have been regularly trained & adequately exercised for a span of 24 weeks by a yoga instructor & physical trainer. They noticed all the base line parameters. The study of HRV was derived from an ECG unit. The parameters were compared at baseline (by paired t-test) in both groups before & after 24 weeks in Group B & Group A by unpaired t-test & were determined with latest SPSS version software. Results: The male-female ratio was comparable in both the groups as 2.5 : 1 & 1.9 : 1 groups (p>0.05). There was a substantial difference in changes over 12 weeks (p>0.05). The high-frequency HRV increased in the yoga community, where the reduction in the exercise group was statistically significant (p <0.05) & the decrease in the low frequency HRV & LF/HF ration was statistically significant (p <0.05) after 12 weeks of intervention. Conclusion: From our research, it can be inferred that the Yoga group substantially raises the high frequency HRV & reduces the low frequency HRV, so that the parasympathetic activity is more determined in the Yoga group compared to the aerobic exercise group. Keyword: HRV, Parasympathetic activity, Yoga, Aerobic exercise, ECG

Neural factors that define religiosity: neurophysiological distinction between the individual with religious and non-religious beliefs

Introduction: Religiosity and mystical experiences accompany society throughout history, integrating its identity formation. Neuroscience unveils neural correlations, maps the areas involved and activity patterns, and functional magnetic resonance imaging (fMRI) is applied to detect variations in activation of neural activity. Objectives: Thus, the objective is to understand the neurophysiological differences between individuals who experience religiosity and the mystical experiences of those without, through the fMRI. Methods: This literature review, collected data in April/2021 on Medline, Pubmed and Science Direct. The descriptors used, after consulting the MeSH, consisted of “neural correlates of religious”, “mystical experience” and “functional magnetic resonance imaging (fMRI)”. Were found 227 articles, after applying the exclusion criteria and fully reading of the abstract, the sample included 6 articles in English, from the last 10 years, available in full text, 2 Medline, 3 Pubmed and 1 Science Direct. Results: The consensus was reached that religiosity can be grounded by neural factors, by applying fMRI to identify patterns of activation of brain regions during mystical experience, although one of the articles refutes these relationships. Correlations are cited by regions: frontal and temporal - emphasis on the dorsolateral and medial/superior prefrontal cortex and bilateral lower parietal lobes, as promoters or impeders of the religious profile in individuals, due to the negative regulation due to lack of excitement, injuries or structural changes. Conclusions: It is concluded that the neurophysiological findings were able to detect patterns that can serve as eligibility criteria between believing and non- believing individuals, which makes their subsequent application feasible for better clarification and neural distinction.

Dementia in Parkinson’s Disease: it’s Therapeutics

Background: Dementia is a cognitive degenerative disease generally associated with Alzheimer disease, but victims with Parkinson’s disease also develops dementia at the latter stage. Dementia associates with irreversible loss of memory, and no medicinal cure is yet available. We here put some light on possible cell therapy for dementia. Aim: Neural stem cells are multipotent cells which are capable of self-replication and differentiation into neurons, astrocytes or oligodendrocytes in the central nervous system. They produce Dopamine, neural factors, and therefore, one can expect that NSC transplantation can ultimately provide a better therapeutic approach in the treatment of dementia as well as Parkinson’s disease (PD). Methods: We discussed the merits and demerits of using hNSCs cells over other possible candidate cells. Results: As we found that hNSCs can secrete Dopamine as well as some neurotropic factors, like Brain-Derived Neurotropic Factor (BDNF) and Glial cell-Derived Neurotropic Factors (GDNF) which can support the proliferation of hNSCS and its Dopamine production ability, hNSCs can supply dopamine and also can stop α-synuclein aggregation. Conclusion: hNSCs, therefore, could be a better cell regiment for cell transplantation therapy for dementia as well as PD.

Interpreting the Effect of Stimulus Parameters on the Electrically Evoked Compound Action Potential and on Neural Health Estimates

Variations in the condition of the neural population along the length of the cochlea can degrade the spectral and temporal representation of sounds conveyed by CIs, thereby limiting speech perception. One measurement that has been proposed as an estimate of neural survival (the number of remaining functional neurons) or neural health (the health of those remaining neurons) is the effect of stimulation parameters, such as the interphase gap (IPG), on the amplitude growth function (AGF) of the electrically evoked compound action potential (ECAP). The extent to which such measures reflect neural factors, rather than non-neural factors (e.g. electrode orientation, electrode-modiolus distance, and impedance), depends crucially upon how the AGF data are analysed. However, there is currently no consensus in the literature for the correct method to interpret changes in the ECAP AGF due to changes in stimulation parameters. We present a simple theoretical model for the effect of IPG on ECAP AGFs, along with a re-analysis of both animal and human data that measured the IPG effect. Both the theoretical model and the re-analysis of the animal data suggest that the IPG effect on ECAP AGF slope (IPG slope effect), measured using either a linear or logarithmic input-output scale, does not successfully control for the effects of non-neural factors. Both the model and the data suggest that the appropriate method to estimate neural health is by measuring the IPG offset effect, defined as the dB offset between the linear portions of ECAP AGFs for two stimuli differing only in IPG.

Different lineage contexts direct common pro-neural factors to specify distinct retinal cell subtypes

How astounding neuronal diversity arises from variable cell lineages in vertebrates remains mostly elusive. By in vivo lineage tracing of ∼1,000 single zebrafish retinal progenitors, we identified a repertoire of subtype-specific stereotyped neurogenic lineages. Remarkably, within these stereotyped lineages, GABAergic amacrine cells were born with photoreceptor cells, whereas glycinergic amacrine cells were born with OFF bipolar cells. More interestingly, post-mitotic differentiation blockage of GABAergic and glycinergic amacrine cells resulted in their respecification into photoreceptor and bipolar cells, respectively, suggesting lineage constraint in cell subtype specification. Using single-cell RNA-seq and ATAC-seq analyses, we further identified lineage-specific progenitors, each defined by specific transcription factors that exhibited characteristic chromatin accessibility dynamics. Finally, single pro-neural factors could specify different neuron types/subtypes in a lineage-dependent manner. Our findings reveal the importance of lineage context in defining neuronal subtypes and provide a demonstration of in vivo lineage-dependent induction of unique retinal neuron subtypes for treatment purposes.

Advanced quantitative estimation methods for spasticity: a literature review

Post-stroke spasticity seriously affects patients’ quality of life. Spasticity is considered to involve both neural and non-neural factors. Current clinical scales, such as the Modified Ashworth Scale and the Modified Tardieu Scale, lack reliability and reproducibility. These scales are also unable to identify the neural and non-neural contributions to spasticity. Surface electromyography and biomechanical and myotonometry measurement methods for post-stroke spasticity are discussed in this report. Surface electromyography can provide neural information, while myotonometry can estimate muscular properties. Both the neural and non-neural contributions can be estimated by biomechanical measurement. These laboratory methods can quantitatively assess spasticity. They can provide more valuable information for further study on treatment and rehabilitation than clinical scales.