Halil Aziz Velioglu

Dr. Halil Aziz Velioglu


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 January 2023 in Biomedicine & Pharmacotherapy
Verified
Journal Article
Open access
MOMehmet Ozansoy
Mehmet Ozansoy
HMHouda Mikati
Houda Mikati
HVHalil Aziz Velioglu
Halil Aziz Velioglu
BYBurak Yulug
Burak Yulug
Exosomes are potent mediators of physiological and pathological processes. In Alzheimer's disease and inflammatory disorders, due to exosomes' distinctive ability to cross the blood-brain barrier, a bidirectional communication between the periphery and the central nervous system exists. Since exosomes can carry various biochemical molecules, this review investigates the role of exosomes as possible mediators between chronic systemic inflammatory diseases and Alzheimer's disease. Exosomes carry pro-inflammatory molecules generated in the periphery, travel to the central nervous system, and target glial and neuronal cells. Microglia and astrocytes then become activated, initiating chronic neuroinflammation. As the aging brain is more susceptible to such changes, this state of neuroinflammation can stimulate neuropathologies, impair amyloid-beta clearance capabilities, and generate dysregulated microRNAs that alter the expression of genes critical in Alzheimer's disease pathology. These processes, individually and collectively, become significant risk factors for the development of Alzheimer's disease.

25 June 2024 in Translational Psychiatry
Verified
Journal Article
Open access
PDF file
BÖBeyza Nur ÖZKAN
Beyza Nur ÖZKAN
KBKübra Bozali
Kübra Bozali
MBMuhammed Emin Boylu
Muhammed Emin Boylu
HVHalil Aziz Velioglu
Halil Aziz Velioglu
SASelman Aktas
Selman Aktas
EGEray Metin Guler
Eray Metin Guler
Major depressive disorder (MDD) is a debilitating illness that includes depressive mood. Repetitive Transcranial Magnetic Stimulation (rTMS) is a therapy method used in the treatment of MDD. The purpose of this study was to assess neurotrophic factors, and oxidative stress levels in MDD patients and evaluate the changes in these parameters as a result of rTMS therapy. Twenty-five patients with MDD and twenty-six healthy volunteers with the same demographic characteristics were included in the study. Brain-derived neurotrophic factors were measured photometrically with commercial kits. Oxidative stress parameters were measured by the photometric method. Oxidative stress index (OSI) and disulfide (DIS) levels were calculated with mathematical formulas. In this study, total antioxidant status (TAS), total thiol (TT), and native thiol (NT) antioxidant parameters and brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and allopregnanolone (ALLO) levels were reduced in pre-rTMS with regard to the healthy control group; TOS, OSI, DIS, and S100 calcium-binding protein B (S100B) levels were increased statistically significantly (p < 0.01). Moreover, owing to TMS treatment; TAS, TT, NT, BDNF, GDNF, and ALLO levels were increased compared to pre-rTMS, while DIS, TOS, OSI, and S100B levels were decreased significantly (p < 0.01). The rTMS treatment reduces oxidative stress and restores thiol-disulfide balance in MDD patients. Additionally, rTMS modulates neurotrophic factors and neuroactive steroids, suggesting its potential as an antidepressant therapy. The changes in the biomarkers evaluated may help determine a more specific approach to treating MDD with rTMS therapy.

27 January 2023 in Biomedicine & Pharmacotherapy
Verified
Journal Article
Open access
BYBurak Yulug
Burak Yulug
HVHalil Aziz Velioglu
Halil Aziz Velioglu
DSDila Sayman
Dila Sayman
SCSeyda Cankaya
Seyda Cankaya
LHLütfü Hanoglu
Lütfü Hanoglu
Brain temperature determines not only an individual's cognitive functionality but also the prognosis and mortality rates of many brain diseases. More specifically, brain temperature not only changes in response to different physiological events like yawning and stretching, but also plays a significant pathophysiological role in a number of neurological and neuropsychiatric illnesses. Here, we have outlined the function of brain hyperthermia in both diseased and healthy states, focusing particularly on the amyloid beta aggregation in Alzheimer's disease.

12 January 2024 in CNS Neuroscience & Therapeutics
Verified
Journal Article
Open access
HVHalil Aziz Velioglu
Halil Aziz Velioglu
EDEsra Zeynep Dudukcu
Esra Zeynep Dudukcu
LHLutfu Hanoglu
Lutfu Hanoglu
BGBahar Guntekin
Bahar Guntekin
TATuba Akturk
Tuba Akturk
BYBurak Yulug
Burak Yulug
Background: Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising alternative therapy for Alzheimer's disease (AD) due to its ability to modulate neural networks and enhance cognitive function. This treatment offers the unique advantage of enabling real‐time monitoring of immediate cognitive effects and dynamic brain changes through electroencephalography (EEG).Objective: This study focused on exploring the effects of left parietal rTMS stimulation on visual‐evoked potentials (VEP) and visual event‐related potentials (VERP) in AD patients.Methods: Sixteen AD patients were recruited for this longitudinal study. EEG data were collected within a Faraday cage both pre‐ and post‐rTMS to evaluate its impact on potentials.Results: Significant alterations were found in both VEP and VERP oscillations. Specifically, delta power in VEP decreased, while theta power in VERP increased post‐rTMS, indicating a modulation of brain activities.Discussion: These findings confirm the positive modulatory impact of rTMS on brain activities in AD, evidenced by improved cognitive scores. They align with previous studies highlighting the potential of rTMS in managing hyperexcitability and oscillatory disturbances in the AD cortex.Conclusion: Cognitive improvements post‐rTMS endorse its potential as a promising neuromodulatory treatment for cognitive enhancement in AD, thereby providing critical insights into the neurophysiological anomalies in AD and possible therapeutic avenues.

9 November 2021 in Clinical Eeg and Neuroscience
Verified
Journal Article
Closed access
PDF file
LHLutfu Hanoglu
Lutfu Hanoglu
HVHalil Aziz Velioglu
Halil Aziz Velioglu
THTaha Hanoglu
Taha Hanoglu
BYBurak Yulug
Burak Yulug
The therapeutic approaches currently applied in Alzheimer's disease (AD) and similar neurodegenerative diseases are essentially based on pharmacological strategies. However, despite intensive research, the effectiveness of these treatments is limited to transient symptomatic effects, and they are still far from exhibiting a true therapeutic effect capable of altering prognosis. The lack of success of such pharmacotherapy-based protocols may be derived from the cases in the majority of trials being too advanced to benefit significantly in therapeutic terms at the clinical level. For neurodegenerative diseases, mild cognitive impairment (MCI) may be an early stage of the disease continuum, including Alzheimer's. Noninvasive brain stimulation (NIBS) techniques have been developed to modulate plasticity in the human cortex in the last few decades. NIBS techniques have made it possible to obtain unique findings concerning brain functions, and design novel approaches to treat various neurological and psychiatric conditions. In addition, its synaptic and cellular neurobiological effects, NIBS is an attractive treatment option in the early phases of neurodegenerative diseases, such as MCI, with its beneficial modifying effects on cellular neuroplasticity. However, there is still insufficient evidence about the potential positive clinical effects of NIBS on MCI. Furthermore, the huge variability of the clinical effects of NIBS limits its use. In this article, we reviewed the combined approach of NIBS with various neuroimaging and electrophysiological methods. Such methodologies may provide a new horizon to the path for personalized treatment, including a more individualized pathophysiology approach which might even define new specific targets for specific symptoms of neurodegenerations.

14 December 2022 in Human Brain Mapping
Verified
Journal Article
Open access
SASevilay Ayyildiz
Sevilay Ayyildiz
HVHalil Aziz Velioglu
Halil Aziz Velioglu
BABehcet Ayyildiz
Behcet Ayyildiz
BSBernis Sutcubasi
Bernis Sutcubasi
LHLutfu Hanoglu
Lutfu Hanoglu
BYBurak Yulug
Burak Yulug
The claustrum is a sheet‐like of telencephalic gray matter structure whose function is poorly understood. The claustrum is considered a multimodal computing network due to its reciprocal connections with almost all cortical areas as well as subcortical structures. Although the claustrum has been involved in several neurodegenerative diseases, specific changes in connections of the claustrum remain unclear in Alzheimer's disease (AD), and Parkinson's disease (PD). Resting‐state fMRI and T1‐weighted structural 3D images from healthy elderly (n = 15), AD (n = 16), and PD (n = 12) subjects were analyzed. Seed‐based FC analysis was performed using CONN FC toolbox and T1‐weighted images were analyzed with the Computational Anatomy Toolbox for voxel‐based morphometry analysis. While we observed a decreased FC between the left claustrum and sensorimotor cortex, auditory association cortex, and cortical regions associated with social cognition in PD compared with the healthy control group (HC), no significant difference was found in alterations in the FC of both claustrum comparing the HC and AD groups. In the AD group, high FC of claustrum with regions of sensorimotor cortex and cortical regions related to cognitive control, including cingulate gyrus, supramarginal gyrus, and insular cortex were demonstrated. In addition, the structural results show significantly decreased volume in bilateral claustrum in AD and PD compared with HC. There were no significant differences in the claustrum volumes between PD and AD groups so the FC may offer more precise findings in distinguishing changes for claustrum in AD and PD.