Pattern and component responses of primate MT neurons recorded with multi-contact electrodes, stimulated with 1D and 2D noise patterns.

Direction selective neurons in primary visual cortex (area V1) are affected by the aperture problem, i.e., they are only sensitive to motion orthogonal to their preferred orientation. A solution to this problem first emerges in the middle temporal (MT) area, where a subset of neurons (called pattern cells) combine motion information across multiple orientations and directions, becoming sensitive to pattern motion direction. These cells are expected to play a prominent role in subsequent neural processing, but they are intermixed with cells that behave like V1 cells (component cells), and others that do not clearly fall in either group. The picture is further complicated by the finding that cells that behave like pattern cells with one type of pattern, might behave like component cells for another. We recorded from macaque MT neurons using multi-contact electrodes while presenting both type I and unikinetic plaids, in which the components were 1D noise patterns. We found that the indices that have been used in the past to classify neurons as pattern or component cells work poorly when the properties of the stimulus are not optimized for the cell being recorded, as is always the case with multi-contact arrays. We thus propose alternative measures, which considerably ameliorate the problem, and allow us to gain insights in the signals carried by individual MT neurons. We conclude that arranging cells along a component-to-pattern continuum is an oversimplification, and that the signals carried by individual cells only make sense when embodied in larger populations.

The retrocalcarine sulcus maps different retinotopic representations in macaques and humans

Primate cerebral cortex is highly convoluted with much of the cortical surface buried in sulcal folds. The origins of cortical folding and its functional relevance have been a major focus of systems and cognitive neuroscience, especially when considering stereotyped patterns of cortical folding that are shared across individuals within a primate species and across multiple species. However, foundational questions regarding organizing principles shared across species remain unanswered. Taking a cross-species comparative approach with a careful consideration of historical observations, we investigate cortical folding relative to primary visual cortex (area V1). We identify two macroanatomical structures—the retrocalcarine and external calcarine sulci—in 24 humans and 6 macaque monkeys. We show that within species, these sulci are identifiable in all individuals, fall on a similar part of the V1 retinotopic map, and thus, serve as anatomical landmarks predictive of functional organization. Yet, across species, the underlying eccentricity representations corresponding to these macroanatomical structures differ strikingly across humans and macaques. Thus, the correspondence between retinotopic representation and cortical folding for an evolutionarily old structure like V1 is species-specific and suggests potential differences in developmental and experiential constraints across primates.

Comparable and adaptable strategies to waterlogging stress regulated by adventitious roots between two contrasting species

Cleistocalyx operculatus and Syzygium cumini possess a certain waterlogging tolerance. However, the comparable and adaptable strategies to waterlogging stress between these two species on the basis of waterlogging adventitious root (AR) regulation were still unclear. In this study, the plant performances in response to AR regulation based on AR removal and exogenous hormone application were investigated in terms of plant morphology, physiology, photosynthesis, and AR traits. Results showed that C. operculatus possesses stronger waterlogging tolerance than S. cumini based on waterlogging tolerance coefficient, which is mainly due to the higher root biomass, root porosity, and length and activity of ARs, and shorter emergence time of ARs in C. operculatus than in S. cumini. The AR-R treatment increased activity and porosity of primary root, and induce a large amount of up-vertical ARs from the primary root systems in C. operculatus, while similar adaptive morphological changes in roots did not occur in AR-R treated S. cumini. Exogenous ABA application had better effects on alleviating waterlogging damages than exogenous IAA in balancing endogenous hormones (ABA and ZR), promoting ARs development (porosity and activity, and the ratio of cortex area to stele area), improving photosynthesis process and antioxidant system (soluble protein, free proline, and peroxidase). Moreover, under waterlogging conditions, exogenous ABA application induced greater increases in net photosynthesis rate (A), stomatal conductance (gs), chlorophyll b (Chl b), and carotenoid (Caro) in S. cumini than in C. operculatus, which suggested that S. cumini responded more positively and efficiently to exogenous ABA application than C. operculatus under waterlogging conditions. Thus, the findings provided new insights into the waterlogging adaptable strategies in waterlogging tolerant woody species on the basis of ARs, and could provide scientific guidance for the application of these two species during revegetation activities in wetlands.

Anatomical Comparison of Two Grammatophyllum spp. (Orchidaceae) Species and Their Specific Ecological Adaptation

The genus Grammatophyllum (Orchidaceae) has two sections with a very different habitus. The Grammatophyllum from section “Grammatophyllum” has a long cylindrical pseudobulb with linear leaves, while the Grammatophyllum section “Gabertia” has a shorter pseudobulb with a larger diameter and broader lanceolate shaped leaves. The study is aimed to compare the anatomical characters of leaf and root between G. speciosum (representation of “Pattonia” section) and G. scriptum (representation of “Gabertia” section). Leaf and root sections were obtained using the mini-microtome with liquid preservation method in 10 replications. Data were analyzed statistically using a t-test at 5% significance. The results showed significant differences between the two species in the leaf’s primary vascular bundle area, velamen area, number of velamen layers, root’s cortex area, and stele area. Future research with more organs and parameters being explored and experimental research regarding its anatomical response to drought is suggested.

The Changes in Concentration of Cerebral Oxygenated Hemoglobin During Single Event-Related Japanese Shiritori Task in Patients With Major Depression Disorder: Comparison With Healthy Subjects

Patients with major depressive disorder (MDD) have been reported to show cognitive impairments in attention, cognition control, and motivation. The purpose of this study is to compare and examine the characteristics of frontal and temporal cortical activity in outpatients with MDD during the word production task (Shiritori) using a single event-related Near-Infrared Spectroscopy (NIRS) measurement method that was originally devised. The subjects were 29 MDD patients and 29 age matched healthy controls. In this task, one session consisted of two contrasting conditions (word production task, control condition), and all subjects alternated between these conditions. Each word was visually presented by a monitor for 0.3 s as an activation task and a fixed circle was presented for 12 s. In the activation task, subjects had to immediately generate a noun that starts with the last syllable of the presented word and they were required to say only creatures. From the data obtained at each measurement point during the 20 trials, and averaged waveform during activation task (20 trials) was calculated for each channel. During the word production task, the MDD patients showed significantly smaller activation than the controls in the prefrontal cortex area and inferior parietal area, especially in the left area. In addition, there was a significant negative correlation between Δoxy-Hb at the bilateral temporal lobe area and HAM-D total score in the MDD patients. These findings suggest that a single event-related NIRS measurement during Japanese shiritori tasks may be useful tool for evaluating psychophysiological indices in MDD patients, that relationship between activation and symptom may be of help in predicting functional outcome in patients.

Anatomy and histology of the thymus of American mink genotypes Standard, Sapphire, Lavander in the early postnatal period of ontogenesis

Data are presented on the thymus structure of American Mink of the Standard, Sapphire, Lavender colouring genotypes in the early postnatal period from birth to 180 days. The thymus is known to be a fully formed organ at birth. The anatomical structure of the thymus and its topography are not determined by genotype. At 45 days of age, the changes are manifested by an increase in the thymic lobule area and the brain matter therein, a decrease in the cortex area; the most intense growth of the thymus due to the rise in the number of lobules is noted. The thymus of mink at 45 to 90 days of age is characterised by an equalisation between the genotypes, increasing cortical area values to about the level of newborn mink with a corresponding increase in the cortical-brain index. The thymus of minks at the age of 90 to 180 days retains the typical morphological structure. Still, the signs of age involutive processes are seen – reduction of the lobule area, enlargement of the medulla, changes in the form of the organ (lobule fusion), increased signs of fat transformation thymus. Hassall’s corpuscles were found in the medulla in all periods of investigation. The number of Hassall’s bodies and their morphology depends on the functional activity of the thymus. In newborns, unicellular, young and juvenile forms predominate. In 45-day-old minks, young and immature forms predominate. In 90-day-old female and male Standard burros, young and quite often unicellular bodies are visualised, while mature and juvenile records are less common. In mink of the coloured genotypes, immature and youthful Hassall’s corpuscles are predominant. By 180 days, the number of mature and young corpuscles with signs of central cell destruction with detritus accumulation and cavity formation increases.

Diagnosis of hearing deficiency using EEG based AEP signals: CWT and improved-VGG16 pipeline

Hearing deficiency is the world’s most common sensation of impairment and impedes human communication and learning. Early and precise hearing diagnosis using electroencephalogram (EEG) is referred to as the optimum strategy to deal with this issue. Among a wide range of EEG control signals, the most relevant modality for hearing loss diagnosis is auditory evoked potential (AEP) which is produced in the brain’s cortex area through an auditory stimulus. This study aims to develop a robust intelligent auditory sensation system utilizing a pre-train deep learning framework by analyzing and evaluating the functional reliability of the hearing based on the AEP response. First, the raw AEP data is transformed into time-frequency images through the wavelet transformation. Then, lower-level functionality is eliminated using a pre-trained network. Here, an improved-VGG16 architecture has been designed based on removing some convolutional layers and adding new layers in the fully connected block. Subsequently, the higher levels of the neural network architecture are fine-tuned using the labelled time-frequency images. Finally, the proposed method’s performance has been validated by a reputed publicly available AEP dataset, recorded from sixteen subjects when they have heard specific auditory stimuli in the left or right ear. The proposed method outperforms the state-of-art studies by improving the classification accuracy to 96.87% (from 57.375%), which indicates that the proposed improved-VGG16 architecture can significantly deal with AEP response in early hearing loss diagnosis.

Inferring entire spiking activity from local field potentials

Extracellular recordings are typically analysed by separating them into two distinct signals: local field potentials (LFPs) and spikes. Previous studies have shown that spikes, in the form of single-unit activity (SUA) or multiunit activity (MUA), can be inferred solely from LFPs with moderately good accuracy. SUA and MUA are typically extracted via threshold-based technique which may not be reliable when the recordings exhibit a low signal-to-noise ratio (SNR). Another type of spiking activity, referred to as entire spiking activity (ESA), can be extracted by a threshold-less, fast, and automated technique and has led to better performance in several tasks. However, its relationship with the LFPs has not been investigated. In this study, we aim to address this issue by inferring ESA from LFPs intracortically recorded from the motor cortex area of three monkeys performing different tasks. Results from long-term recording sessions and across subjects revealed that ESA can be inferred from LFPs with good accuracy. On average, the inference performance of ESA was consistently and significantly higher than those of SUA and MUA. In addition, local motor potential (LMP) was found to be the most predictive feature. The overall results indicate that LFPs contain substantial information about spiking activity, particularly ESA. This could be useful for understanding LFP-spike relationship and for the development of LFP-based BMIs.

Cytoarchitectonics of the Superior Parietal Cortex of an Outstanding Russian Scientist-Physiologist

The aim of the study is to identify possible cytoarchitectonic features of the structure of the cortex in the superior parietal region of an outstanding and talented scientist-physiologist.Material and methods. The cortex (area 7) of the superior parietal region of a scientist-physiologist and men of the senile age in the control group (8 hemispheres) was studied on the series of frontal brain slices, 20 μ thick, stained with cresyl purple according to Nissl method. The cortex area thickness, the thickness of the cytoarchitectonics layer III, the area of profile field of pyramidal neurons in layers III and V, the density of neurons surrounded by satellite glia and satellite glia density in layers III and V were measured in the cortex (area 7) of the superior parietal region in the left and right hemispheres of the brain.Results. We have identified several features of the cytoarchitectonics structure of the cortex (area 7) in the brain of the scientist-physiologist that may correlate with his outstanding scientific abilities. The cortex of a scientist-physiologist is characterized by a large thickness of the studied cortex and its cytoarchitectonic layers III and V, and a greater value of the area of the profile field of neurons if compared with the cortex in men of the senile age from the control group. A higher value of the neuron density and satellite glia in the cortex of the superior parietal region of the scientist-physiologist was revealed. There was also a lower severity of age-related changes in the cortex of the scientist-physiologist compared with the control group of men.Conclusion. The structure of the cortex (area 7) of the superior parietal region of the scientistphysiologist is characterized by a greater parameter of the cortical thickness and the thickness of the associative layer III, the size of neurons and the density of satellite glia if compared with those in men of the senile age of the control group. These features distinguish the structure of his cortex from the similar cortex of the control group of men and may be related to the features of the cognitive activity of the outstanding scientist-physiologist.

Adrenal glands of mice and rats: A comparative morphometric study

Mice and rats are among the most used laboratory animals. They share numerous similarities along with differences, some yet unexplored. One of them is the morphometry of their adrenal glands, whose characteristics may be related to differences in energy management, immune response, drug metabolism, behaviour and temperament. The present study tries to fill this knowledge gap with the evaluation and comparison of adrenal gland anatomical/morphometric parameters of mice and rats. In groups of 10 ( n = 10) adult, male and female BALB/c mice and Wistar rats, one in every 20 sections transverse to the longitudinal axis of the gland was used for measuring entire gland area, capsule, entire cortex, cortex zones and medulla with the aid of an image analysis system and subjected to statistical analysis. Quotients of the individual areas were calculated and comparison between the resulting ratios was performed. Gland length and volume were also calculated. Statistically significant differences were revealed between the rat female and male cortex area, rat and mouse medulla/cortex, medulla/gland, zona glomerulosa/cortex and cortex/gland ratios, male and female rats’ medulla/cortex, medulla/gland, capsule/gland, zona glomerulosa/cortex, zona reticularis/cortex and zona glomerulosa/zona fasciculata ratios, length and volume. The correlation evaluation revealed that in male rats and in female mice the larger medulla area was accompanied by a larger cortex area and vice versa. In general, a larger cortex area was accompanied by larger areas of cortex zones. The collected data and the revealed differences can possibly contribute to the understanding of the physiology of the two species.