Person: ÖZKAN, MAZHAR
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
ÖZKAN
First Name
MAZHAR
Name
4 results
Search Results
Now showing 1 - 4 of 4
Publication Open Access Phase-amplitude coupled persistent theta and gamma oscillations in rat primary motor cortex in vitro(PERGAMON-ELSEVIER SCIENCE LTD, 2017-06) ÖZKAN, MAZHAR; Johnson, Nicholas W.; Ozkan, Mazhar; Burgess, Adrian P.; Prokic, Emma J.; Wafford, Keith A.; O'Neill, Michael J.; Greenhill, Stuart D.; Stanford, Ian M.; Woodhall, Gavin L.In vivo, theta (4-7 Hz) and gamma (30-80 Hz) neuronal network oscillations are known to coexist and display phase-amplitude coupling (PAC). However, in vitro, these oscillations have for many years been studied in isolation. Using an improved brain slice preparation technique we have, using co-application of carbachol (10 mu M) and kainic acid (150 nM), elicited simultaneous theta (6.6 +/- 0.1 Hz) and gamma (36.6 +/- 0.4 Hz) oscillations in rodent primary motor cortex (M1). Each oscillation showed greatest power in layer V. Using a variety of time series analyses we detected significant cross-frequency coupling in 74% of slice preparations. Differences were observed in the pharmacological profile of each oscillation. Thus, gamma oscillations were reduced by the GABAA receptor antagonists, gabazine (250 nM and 2 mu M), and picrotoxin (50 mu M) and augmented by AMPA receptor antagonism with SYM2206 (20 mu M). In contrast, theta oscillatory power was increased by gabazine, picrotoxin and SYM2206. GABA(B) receptor blockade with CGP55845 (5 mu M) increased both theta and gamma power, and similar effects were seen with diazepam, zolpidem, MK801 and a series of metabotropic glutamate receptor antagonists. Oscillatory activity at both frequencies was reduced by the gap junction blocker carbenoxolone (200 mu M) and by atropine (5 mu). These data show theta and gamma oscillations in layer V of rat M1 in vitro are cross-frequency coupled, and are mechanistically distinct. The development of an in vitro model of phase-amplitude coupled oscillations will facilitate further mechanistic investigation of the generation and modulation of coupled activity in mammalian cortex. (C) 2017 The Authors. Published by Elsevier Ltd.Publication Metadata only Morphometric characteristics of caudal cranial nerves at petroclival region in fetuses(SPRINGER, 2016) ÖZKAN, MAZHAR; Ozdogmus, Omer; Saban, Enis; Ozkan, Mazhar; Yildiz, Sercan Dogukan; Verimli, Ural; Cakmak, Ozgur; Arifoglu, Yasin; Sehirli, UmitMorphometric measurements of cranial nerves in posterior cranial fossa of fetus cadavers were carried out in an attempt to identify any asymmetry in their openings into the cranium. Twenty-two fetus cadavers (8 females, 14 males) with gestational age ranging between 22 and 38 weeks (mean 30 weeks) were included in this study. The calvaria were removed, the brains were lifted, and the cranial nerves were identified. The distance of each cranial nerve opening to midline and the distances between different cranial nerve openings were measured on the left and right side and compared. The mean clivus length and width were 21.2 +/- A 4.4 and 13.2 +/- A 1.5 mm, respectively. The distance of the twelfth cranial nerve opening from midline was shorter on the right side when compared with the left side (6.6 +/- A 1.1 versus 7.1 +/- A 0.8 mm, p = 0.038). Openings of other cranial nerves did not show such asymmetry with regard to their distance from midline, and the distances between different cranial nerves were similar on the left and right side. Cranial nerves at petroclival region seem to show minimal asymmetry in fetuses.Publication Open Access The failure on the effectiveness of formalin on cadaver disinfection and alternative methods(2023-01-01) AKSU, MEHMET BURAK; ÖZKAN, MAZHAR; ŞEHİRLİ, ÜMİT SÜLEYMAN; Yanilmaz O., Guncu M. M., AKSU M. B., ÖZKAN M., ŞEHİRLİ Ü. S.Objective: It was aimed to identify the contaminant and determine the alternative disinfectant detection in the microbial growth observed in various parts of the cadaver stored in the formalin tank in the dissection laboratory of Marmara University Anatomy Department. We also performed a literature review of this unusual pathogen. Materials and Methods: Swab samples were inoculated on agar mediums. After incubation, matrix-assisted laser desorption ionizationtime of flight mass spectrometry (MALDI-TOF MS) analysis was used to identify the isolate from the detected uniform colonies. Sample solution from the cadaver tank, freshly prepared 5% formalin and 0.55% ortho-phthalaldehyde were used to determine the disinfectant sensitivity of the isolate. Results: According to 16s rDNA sequence analysis, it was concluded as Skermanella aerolata with 99% similarity. In the disinfectant susceptibility test, it was observed that S. aerolata and control bacteria could grow in 5% formalin taken from the cadaver tank. No growth was detected in other disinfectants. Conclusion: To prevent cadaver contamination in anatomy laboratories, the quality control of the embalming solutions and indoor air filtration of the dissection rooms should be checked at regular intervals. Members of Skermanella genus have been identified as environmental organisms in several studies, however, recent researches reported this bacterium as a human pathogen.Publication Metadata only Prelimbic Cortex Deep Brain Stimulation Reduces Binge Size in a Chronic Binge Eating Rat Model(KARGER, 2018) ONAT, FİLİZ; Sarica, Can; Ozkan, Mazhar; Bay, Husniye Hacioglu; Sehirli, Umit; Onat, Filiz; Ziyal, M. IbrahimBackground: Binge eating (BE) involves the consumption of a large amount of food in a short period of time and a loss of control during the binge episode. It is a key feature of the major subtypes of eating disorders like bulimia nervosa, BE disorder, anorexia nervosa binge/purge type. Alterations in the mesocorticolimbic pathway play a crucial role in its pathophysiology. Objectives: We hypothesized that BE rats receiving deep brain stimulation (DBS) in the prelimbic cortex, a functional analog of the dorsolateral prefrontal cortex in humans, would have a reduced binge size compared with those receiving sham stimulation. Methods: Eight male Sprague-Dawley rats were implanted with a DBS electrode in the left prelimbic cortex. A protocol which included limited access to a sweet-fat diet was used to achieve a chronic BE state in the rats. After reaching a stable binge size, each rat had undergone sham, low-frequency stimulation (60 Hz), and high-frequency (130 Hz) stimulation for 3 sessions each, and 2 consecutive treatments were separated by at least 2 empty sessions to allow a washout of the effects. A one-way ANOVA was used for the data analysis. Results: Low-frequency (60 Hz) stimulation of the prelimbic cortex significantly reduced the binge size compared to the sham stimulation (p < 0.0001). High-frequency DBS (130 Hz) had no significant influence on this behavior when compared to sham stimulation (p = 0.9). Conclusions: This study suggests that low-frequency prelimbic cortex stimulation in BE would be useful for correcting prefrontal hypofunction which is strongly associated with BE and addiction pathogenesis. (c) 2018 S. Karger AG, Basel.