Is amygdala size correlated with stress?

BACKGROUND: One of the important mechanisms that regulate the stress response of the body is hypothalamic pituitary adrenal axis. One of the structures activating this axis is amygdala. We have seen people around who react calmer and cooler to very stressful situations. Are people with smaller amygdala really calmer? Or, can we say that the bigger the amygdala, which is the trigger of the body's response to stress, the more a person panics? Aim of the study is to compare the saliva cortisol levels and amygdala volume. MATERIALS AND METHODS: Study conducted with 63 male students. Magnetic resonance images of students were taken before their final exam to calculate amygdala volumes. Saliva samples of all students were taken two times to detect cortisol levels in saliva. First one was 20 days before the final exam and second one was on the exam day. We assumed that the students were stressful on exam day. RESULTS AND CONCLUSIONS: No statistically significant correlation was found between saliva cortisol levels and amygdala volume in the study.

Exercise is good also for a healthy hippocampus.

OBJECTIVES: The aim of the study was to compare the hippocampus sizes of healthy medical faculty students, who were exposed to an intense data input and who underwent serious learning activity and those of healthy sport faculty students who did sports regularly by using MR images and to examine the relationship between a hippocampus size and intelligence. METHODS: We made the study with 58 healthy young males (27 sport sciences faculty students and 31 medical faculty students). R. B. Cattell 3A Culture Fair Intelligence Test was administered to the volunteers. Following this, we got MR images of our volunteers. RESULTS: We could not find a statistically significant difference between medical faculty students and sport sciences faculty students in terms of hippocampus volumes. We could not find a correlation between IQ values and hippocampus volumes. Also, we could not find a significant difference between a right and left hippocampus. CONCLUSION: While doing sport, blood flow increases in the hippocampus, as in all areas of the body. This increased blood flow creates a stimulating effect on neurogenesis. Neurons, which develop as the result of neurogenesis, mean an increase in volume (Tab. 4, Ref. 54).

Enzymatic behavior of laccase following interaction with γ-CD and immobilization into PCL nanofibers.

This study examines the effects of CD use on enzymatic activity, following enzyme immobilization into nanofibers. There is almost no research available on the change in enzyme activity following interaction with cyclodextrin and electrospun nanofiber mats together. Laccase enzyme was immobilized into nanofibrous structures by various techniques, with and without γ-CD addition, and the enzymatic activity of the laccase was analyzed. SEM, XRD, and FTIR analyses were used for the characterization of the resulting structures. Our results showed that cyclodextrin use has a positive effect on the enzyme's activity, and increases its stability. The enzymes treated by cyclodextrin showed activation after complex formation trials, and no activation loss or enzyme denaturation was detected. Our conclusions were supported by the enzyme activity test results, which also showed that immobilization by encapsulation methods gave better activity results than layering methods. Another important finding concerned the laccase's stable characteristics that helped to maintain its enzyme activation after the freeze drying process. Among all test groups, the best activity result was recorded by laccase-γ-CD complex encapsulated PCL nanofibers with 96.48 U/mg.

Drug delivery system based on cyclodextrin-naproxen inclusion complex incorporated in electrospun polycaprolactone nanofibers.

In this study, we select naproxen (NAP) as a reference drug and electrospun poly (ɛ-caprolactone) (PCL) nanofibers as a fibrous matrix for our drug-delivery system. NAP was complexed with beta-cyclodextrin (ßCD) to form inclusion complex (NAP-ßCD-IC) and then NAP-ßCD-IC was incorporated into PCL nanofibers via electrospinning. The incorporation of NAP without CD-IC into electrospun PCL was also carried out for a comparative study. Our aim is to analyze the release profiles of NAP from PCL/NAP and PCL/NAP-ßCD-IC nanofibers and we investigate the effect of CD-IC on the release behavior of NAP from the nanofibrous PCL matrix. The characterization of NAP-ßCD-IC and the presence of CD-IC in PCL/NAP-ßCD-IC nanofibers were studied by FTIR, XRD, TGA, NMR and SEM. The SEM imaging of the electrospun PCL/NAP and PCL/NAP-ßCD-IC nanofibers reveal that the average fiber diameter of these nanofibers is around 300nm, in addition, the aggregates of CD-IC in PCL/NAP-ßCD-IC nanofibers is observed. The release study of NAP in buffer solution elucidate that the PCL/NAP-ßCD-IC nanofibers have higher release amount of NAP than the PCL/NAP nanofibers due to the solubility enhancement of NAP by CD-IC.

Preservation of cell viability and protein conformation on immobilization within nanofibers via electrospinning functionalized yeast.

We investigate the immobilization of a model system of functionalized yeast that surface-display enhanced green fluorescent protein (eGFP) within chemically crosslinked polyvinyl alcohol (PVA) nanofibers. Yeast is incorporated into water insoluble nanofibrous materials by direct electrospinning with PVA followed by vapor phase chemical crosslinking of the polymer. Incorporation of yeast into the fibers is confirmed by elemental analysis and the viability is indicated by live/dead staining. Following electrospinning and crosslinking, we confirm that the yeast maintains its viability as well as the ability to express eGFP in the correct conformation. This method of processing functionalized yeast may thus be a powerful tool in the direct immobilization of properly folded, active enzymes within electrospun nanofibers with potential applications in biocatalysis.