Effects of excessive sugar consumption on social recognition behavior of rats exposed to prolonged stress
Büyükgüdük, İlkim
Objective: As a result of non-tolerable toxic stress caused by negative life experiences, the first symptoms causing impairment in functionality of an individual are seen in social field. we aim to investigate the alterations in the social recognition and memory tests in excessive sugar consumed animals exposed to single prolonged stress. Methods: Adult female rats (n=15) were divided into two groups and 10% corn syrup was added to the diet of the experimental group for 10 days, while only water and standard pellets were given to the controls. At the end of the diet, single prolonged stress protocol (2 hours immobilization, 20 minutes forced swim and ether until anesthesia) was applied to the animals. Animals were kept under control conditions for 7 days. Animals were conditioned with high...
In subclinical depression in undergraduates, odor-evoked autobiographical memories are relatively less vivid than those evoked with words or photographs.
YAR BERÇEM | Üngüder Yağmur | VELDHUİZEN MARİA GERALDİNE
The specificity of autobiographical memories is reduced in depression. Effects of depression on memory specificity have typically been examined using word cues, but odor cues may be more sensitive. Here, we measured depressive symptom severity in undergraduate students with and without subclinical depression (n = 99, 58 women, 40 men, and one nonbinary) and used word, photograph, or odor cues to examine memory retrieval. Overall, we observed more memories recalled in subclinical depression relative to no depression. We observed no effect of cue type or depression group on autobiographical memories specificity. However, subclinical depression was associated with lower memory pleasantness. Memory vividness was also associated with subclinical depression, mostly in memories evoked by odors. T...
Non-invasive vagus nerve stimulation in a hungry state decreases heart rate variability
Büyükgüdük, ilkim | Yanık, Hüseyin | Yılmaz, Dilan Dneiz | Yar, Berçem | Değirmenci, Evren | Dal, Uğur | Geraldine Veldhuizen, Maria
Vagus nerve signals from the gut to brain carry information about nutrients and drive food reward. Such signals are disrupted by consuming large amounts of high-calorie foods, necessitating greater food intake to elicit a similar neural response. Non‐invasive vagus nerve stimulation (nVNS) via a branch innervating the ear is a candidate treatment for obesity in humans. There is disagreement on the optimal location of nVNS in the ear for experimental and clinical studies. There are also no studies comparing nVNS in hungry and post-prandial states. We aimed to compare ear position(s) for nVNS and explore the effects of nVNS during hungry and post-prandial states on proxies for autonomic outflow (heart-rate variability) and efferent metabolism (gastric wave frequency and resting energy expend...
In subclinical depression in undergraduates, odor-evoked autobiographical memories are relatively less vivid than those evoked with words or photographs.
YAR BERÇEM | Üngüder Yağmur | VELDHUİZEN MARİA GERALDİNE
The specificity of autobiographical memories is reduced in depression. Effects of depression on memory specificity have typically been examined using word cues, but odor cues may be more sensitive. Here, we measured depressive symptom severity in undergraduate students with and without subclinical depression (n = 99, 58 women, 40 men, and one nonbinary) and used word, photograph, or odor cues to examine memory retrieval. Overall, we observed more memories recalled in subclinical depression relative to no depression. We observed no effect of cue type or depression group on autobiographical memories specificity. However, subclinical depression was associated with lower memory pleasantness. Memory vividness was also associated with subclinical depression, mostly in memories evoked by odors. T...
Yemler Bilgisi Yem Teknolojisi ve Balık Besleme
Bilgüven, Murat
Her havuz alanında ya da yetiştirme biriminden elde edilen balık ve dolayısıyla balık yetiştiriciliğinin kârlılığı, büyük ölçüde kullanılan yemin miktarına bağlıdır. Su ürünleri sistemi ne kadar yoğun olursa yemlemenin önemi o kadar fazla olur ve toplam üretim maliyetinde yem maliyetinin payı da o kadar artar. Bilindiği üzere alabalık başta olmak üzere bazı balıkların yetiştiriciliği için akarsu sistemli tesisler kullanılmakta yada sıcaklığın, su bileşiminin ve akıntının dolayısıyla oksijen yoğunluğunun daha iyi olduğu tatlı su ve kıyılarda ise yüzer ağ kafeslerde yetiştiricilik yapılmaktadır. Su ürünleri yetiştiriciliğinin ileri durumda olduğu ülkelerde entansif yetiştiricilik uygulanmakta ve yetiştirme alanlarında birim hacimde maksimum ürün yetiştirilmeye çalışılmaktadır. Bu tür yetişti...
How do menstrual cycle and emotional expressions affect attentional and memory biases?
Doğan, Dilara
While sex differences and menstrual cycle effects in emotional processing and memory are well-documented, findings remain inconsistent. The present study aimed to investigate how emotional facial expressions influence attention and memory, and whether these effects vary across menstrual phases and between sexes. A total of 184 participants (Mage = 20.67, SD = 2.18) were tested, including men and women in five menstrual phases: early follicular (n = 30), late follicular (n = 30), ovulatory (n = 28), early luteal (n = 35), and late luteal (n = 28). Emotional attention was assessed using a flicker change detection task, and recognition memory was measured with a surprise yes/no recognition memory task. Results revealed a robust happiness superiority effect in the flicker task: Changes involvi...
Role of antioxidant defense system and biochemical adaptation on stress tolerance of high mountain and steppe plants
Keleş, Yüksel
Eleven species were collected from Northwest Anatolian mountains (1500–2000 m) and 18 species were collected from the Central Anatolian steppes (850–1000 m) in June 1998 and 1999. In all the species investigated, the water and dry matter percentages and solute contents were measured. The chlorophyll, b-carotene, ascorbate and a-tocopherol contents and catalase (CAT), superoxide dismutase (SOD) andglutathione reductase (GR)enzymeactivities oftheplants werealsodetermined.Thesteppeplantshadlowerwatercontentcomparedwith alpine plants. The chlorophyll contents of the plants investigated did not change with altitude. However, the carotenoid/chlorophyll ratio of alpine plants was found to be significantly higher. The antioxidant/chlorophyll ratio of the trees and shrubs was higher than that of he...
Transcutaneous Vagus Nerve Stimulation Enhances Probabilistic Learning
Büyükgüdük, İlkim | Geraldine Veldhuizen, Maria
tVNS enhances various memory and learning mechanisms, but there is inconclusive evidence on whether probabilistic learning can be enhanced by tVNS. Here, we tested a simplified version of the probabilistic learning task with monetary rewards in a between-participants design with left and right-sided cymba conchae and tragus stimulation (compared to sham stimulation) in a sample of healthy individuals (n = 80, 64 women, on average 26.38 years old). tVNS enhances overall accuracy significantly(p = 4.09 x 10⁻⁰⁴) and reduces response times (p = 1.1006 x 10⁻⁴⁹) in the probabilistic learning phase. Reinforcement learningmodelling of the data revealed that the tVNS group uses a riskier strategy, dedicates more time to stimulus encoding and motorprocesses and exhibits greater reward sensitivity re...
Tastes and retronasal odours evoke a shared flavour-specific neural code in the human insula
Veldhuizen Maria Geraldine
During food consumption, tastes combine with retronasal odours to form flavour, which leads to a link so robust that retronasal odours can elicit taste sensations without concurrent taste stimulation. However, the cortical integration of these parallel sensory signals remains unclear. Here, we combine a flavour-binding paradigm and functional neuroimaging to test whether retronasal odorants evoke encoding patterns in the insula similar to those of their paired tastants. Healthy participants attend a familiarisation session with congruent sweet and savoury flavours followed by two functional MRI (Magnetic Resonance Imaging) sessions where they separately receive the constituent tastants and odorants. Multivariate pattern analysis reveal classification of retronasal odours within the insula,...
University students’ cognitive flexibility and critical thinking dispositions
Karakuş, İsmail
The purpose of this study is to examine whether there are differences in critical thinking dispositions and cognitive flexibility among university students based on gender, grade level, and faculty. Additionally, the study will investigate the relationship between these two concepts and their predictive power. The study was conducted using a relational survey model and included 366 university students selected through maximum diversity sampling. The study involved university students from various faculties and grade levels. Data was collected through a personal information form, cognitive flexibility inventory, and critical thinking disposition scale. The data was analyzed using the SPSS 25 program. The results indicate that university students exhibit relatively high levels of cognitive f...
Corticospinal motor neuron specific transduction of the TARDBP gene via viral vectors
Büyükgüdük, İlkim
Objective: Recent studies show that mutations and overexpression of the TARDBP gene causes pathological aggregates and inclusion bodies in neurons. This is one of the underlying causes of the progressive neuronal degeneration and apoptosis seen in motor neuron diseases. In this study, we investigated the morphological changes in the rat motor cortex after transduction of neurons by viral vectors expressing either full-length hTDP-43 or nuclear localization sequence-deleted hTDP-43 (hTDP-43-ΔNLS). Methods: Experimental (hTDP-43 and hTDP-43-ΔNLS) and control (SF injected) groups of 4 week-old Sprague-Dawley rats (n=6, for each group) received intravenous injection of viral vectors (AAV2-9 serotype, 1.77x1012 vg/kg) designed under the control of a specific promoter (ubiquitin carboxyl-termin...
CAN NON-INVASIVE VAGUS NERVE STIMULATION CONDITION PREFERENCE FOR NEW FLAVORS PAIRED WITH LOW-FAT FOODS?
Büyükgüdük, İlkim | Geraldine Veldhuizen, Maria | Yılmaz, Dilan Deniz | Dal, Uğur
Conditioned flavor preference can be formed when a novel flavor is associated with for example palatable taste and/ or with positive post-digestive effects. Recent research on the vagus nerve (VN) using chemogenetic and optogeneti stimulation has shown that vagal gut-brain communication underlies this learning. If VN activity triggers food reward, we predict that non-invasive VN stimulation (nVNS, compared to pseudo-stimulation) will condition liking for new flavors paired with low-fat foods. In order to select flavors for conditioning, 17 participants tasted and rated 10 flavors using the sip and-spit method. The participants rated liking and wanting. Two flavors that are similarly near to neutral in liking were chosen for the conditioning sessions. To induce associative conditioning, we ...
Alterations in motor functions of rats after systemic delivery of genes encoding native or mutant transactive response DNA-binding protein-43 (TDP-43)
Büyükgüdük, İlkim
Objective: Transactive response-DNA binding proteinopathy (TDP-43) has become a hallmark feature in motor neuron diseases. Not only overexpression, but also deletion of the nuclear localization signal (NLS) causes proteinopathic alterations. We employed viral vector mediated gene transfer method for delivery of genes encoding native or mutant TDP-43 to assess motor functions of young adult male and female Sprague-Dawley rats. Methods: Motor neuron specific targeting of AAV9 vectors were achieved by using a cell type specific promoter (UCHL1). While control animals received SF injection (n=10), experimental groups were injected by either native or NLS-deleted viruses (1.77×1012 vg/kg, n=7/each group), on postnatal day 30. Following systemic injection of viruses, motor coordination of anim...
Ergen Yürütücü İşlevler Envanterinin Türkçe Formunun Psikometrik Özelliklerinin İncelenmesi
Yar, Berçem
Ergen Yürütücü İşlevler Envanteri (EYİE), ergenlerin yürütücü işlevlerini değerlendirmede yaygın olarak kullanılan bir değerlendirme aracıdır. Bu çalışmada, Ergen Yürütücü İşlevler Envanterinin Türkçe formunun (EYİE-TR) psikometrik özellikleri incelenmiştir. Bu amaçla 12-17 yaş arasında 226 (%58) kadın ve 161 (%42) erkek olmak üzere toplam 387 kişi çalışmaya katılmıştır. Katılımcılar, EYİE-TR’nin yanı sıra Conners-Wells Ergen Öz-bildirim Ölçeği (C-WEÖÖ-K), Bilişsel Esneklik Ölçeği (BEÖ) ve Barratt Dürtüsellik Ölçeğini (BDÖ-11) yanıtlamışlardır. Doğrulayıcı Faktör Analizi (DFA) sonuçları uyum iyiliği indekslerinin kabul edilebilir düzeyde olduğunu (χ2(165, N = 387) = 386.038, χ2/sd = 2.340, RMSEA= 0.059, CFI = 0.90) ve Türkçe formun orijinal ölçekte olduğu gibi iki faktörlü (ketleme ve çal...