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Dive into the research topics where Sayad Kocahan is active.

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Featured researches published by Sayad Kocahan.


Behavioural Brain Research | 2012

The effect of neonatal N-methyl-d-aspartate receptor blockade on exploratory and anxiety-like behaviors in adult BALB/c and C57BL/6 mice

Kubra Akillioglu; Seçil Binokay; Sayad Kocahan

N-methyl-D-aspartate (NMDA) receptors play an important role in brain maturation and developmental processes. In our study, we evaluated the effects of neonatal NMDA receptor blockade on exploratory locomotion and anxiety-like behaviors of adult BALB/c and C57BL/6 mice. In this study, NMDA receptor hypofunction was induced 7-10 days after birth using MK-801 in BALB/c and C57BL/6 mice (0.25mg/kg twice a day for 4 days via intraperitoneal injection). The open-field (OF) and elevated plus maze (EPM) tests were used to evaluate exploratory locomotion and anxiety-like behaviors. In the OF, BALB/c mice spent less time in the center of the field (p<0.05) and had less vertical locomotor activity (p<0.01) compared to C57BL/6 mice. In BALB/c mice, MK-801 caused a decrease in vertical and horizontal locomotor activity in the OF test, compared to the control group (p<0.05). In C57BL/6 mice, MK-801 treatment increased horizontal locomotor activity and decreased time spent in the center in the OF test (p<0.05). In the EPM, the number of open-arm entries, the percentage of open-arm time (p<0.01) and total arm entries (p<0.05) were lower in BALB/c mice compared to C57BL/6 mice. In BALB/c mice, MK-801 caused an increase in the percentage of open-arm time compared to the control group (p<0.05). In C57BL/6 mice, MK-801 caused a decrease in the percentage of open-arm time compared to the control group (p<0.05). MK-801 decreased exploratory and anxiety-like behaviors in BALB/c mice. In contrast, MK-801 increased exploratory and anxiety-like behaviors in C57BL/6 mice. In conclusion, hereditary factors may play an important role in neonatal NMDA receptor blockade-induced responses.


Pharmacology, Biochemistry and Behavior | 2012

The investigation of neonatal MK-801 administration and physical environmental enrichment on emotional and cognitive functions in adult Balb/c mice.

Kubra Akillioglu; Emine Babar Melik; Enver Melik; Sayad Kocahan

N-methyl-D-aspartate (NMDA) receptors play an important role in brain maturation and developmental processes. It is known that growing up in an enriched environment has effects on emotional and cognitive performance. In our study, we evaluated the effects of physically enriched environment on the emotional and cognitive functions of the adult brain in the setting of previous NMDA receptor hypoactivity during the critical developmental period of the nervous system. In this study, NMDA receptor blockade was induced 5-10 days postnatally (PD5-10) using MK-801 in mice Balb/c (twice a day 0.25 mg/kg, for 5 days, intraperitoneal). MK-801 was given to developing mice living in a standard (SE) and an enrichment environment (EE) and once the animals reached adulthood, emotional behaviors were evaluated using an open field test (OF) and an elevated plus maze (EPM) test whereas cognitive processes were evaluated using the Morris water-maze (MWM). The EE group showed decreased locomotor activity (p<0.05) in the OF and increased exploratory behaviour (p<0.01) and decreased fear of heights/anxiety-like behaviour (p<0.05) in the EPM test. The EE had positive effects on spatial learning in the MWM (p<0.05). Blockade of the NMDA receptor increased the fear of height (p<0.05), decreased exploratory behaviour and locomotor activity (p<0.001). Also, it led to decreased spatial learning (p<0.05). The decreases in spatial learning and exploratory behaviours and the increase in fear of heights/anxiety-like behaviour with NMDA receptor blockade was not reversed by EE. NMDA receptor blockade during the critical period of development led to deterioration in the emotional and cognitive processes during adulthood. An enriched environmental did not reverse the deleterious effects of the NMDA receptor blockade on emotional and cognitive functions.


International Journal of Developmental Neuroscience | 2014

Enriched environment has limited capacity for the correction of hippocampal memory-dependent schizoid behaviors in rats with early postnatal NMDAR dysfunction.

Enver Melik; Emine Babar; Sayad Kocahan; Mustafa Güven; Kubra Akillioglu

Pre‐ and early postnatal stress can cause dysfunction of the N‐methyl‐d‐aspartate receptor (NMDAR) and thereby promote the development of hippocampus memory‐dependent schizoid abnormalities of navigation in space, time, and knowledge. An enriched environment improves mental abilities in humans and animals. Whether an enriched environment can prevent the development of schizoid symptoms induced by neonatal NMDAR dysfunction was the central question of our paper. The experimental animals were Wistar rats. Early postnatal NMDAR dysfunction was created by systemic treatment of rat pups with the NMDAR antagonist MK‐801 at PD10–20 days. During the development period (PD21–90 days), the rats were reared in cognitively and physically enriched cages. Adult age rats were tested on navigation based on pattern separation and episodic memory in the open field and on auto‐hetero‐associations based on episodic and semantic memory in a step‐through passive avoidance task. The results showed that postnatal NMDAR antagonism caused abnormal behaviors in both tests. An enriched environment prevented deficits in the development of navigation in space based on pattern separation and hetero‐associations based on semantic memory. However, an enriched environment was unable to rescue navigation in space and auto‐associations based on episodic memory. These data may contribute to the understanding that an enriched environment has a limited capacity for therapeutic interventions in protecting the development of schizoid syndromes in children and adolescents.


Annals of General Psychiatry | 2008

A comparative study on the influence of estrous cycle on cognitive and coping behaviors in rats

Emine Babar; Enver Melik; Kubra Akillioglu; Sayad Kocahan

Materials and methods The present study was investigate the influence of estrous cycle in adult female Wistar rats on the responses to emergency novelty by using an open field (OF) and on the recognition of fearful partial or whole cues presented during testing in the passive avoidance (PA) apparatus. In conditioning task, rats recieved a single shock (1 mA) following a 30-s preshock exposure period to the shock associated context of the PA. Estrous cycle phases were determined by vaginal lavage.


Annals of General Psychiatry | 2008

Effects of NMDA receptor blockade in early developmental period on emotional behaviors in adult social isolated rats reared in physical barren and enriched conditions

Sayad Kocahan; Emine Babar; Enver Melik

increase in time spent in the close arms (P<0.05) with increases in ethological type of exploratory behaviors (head streached, P<0.05; upward exploratory behavior, P<0.001; and self-grooming P<0.05), compared to the SI rats reared barren environment. NMDA receptor blockade attenuates the effects of physical enrichment in the EPM. Conclusions These findings indicate that NMDA receptor blockade in the last maturation period of brain development is implicated in forming multiple associations with environment.


Annals of General Psychiatry | 2008

A new method for studying developmental factors in cognitive and emotional behaviors in adult mice

Enver Melik; Emine Babar; Kóbra Akillioglu; Sayad Kocahan

Background It is recognized that mental-emotional diseases can be caused by disturbances of cognitive processes of matching between the current and stored spatial information [1]. Cognitive matching processor is activited in rodents also during a stereotype upward behavior (rears) [2]. In the present study, we used a new method for studing the effects behavioral dissection of rears in developmental period (BDRD) on cognitive and emotional responses of adult mice.


Neurochemical Research | 2013

The effects of N-Methyl-D-Aspartate receptor blockade during the early neurodevelopmental period on emotional behaviors and cognitive functions of adolescent Wistar rats.

Sayad Kocahan; Kubra Akillioglu; Seçil Binokay; Leman Sencar; Sait Polat


Neurochemical Research | 2013

Effects of NMDA Receptor Blockade During the Early Development Period on the Retest Performance of Adult Wistar Rats in the Elevated Plus Maze

Sayad Kocahan; Kubra Akillioglu


Turkiye Klinikleri Tip Bilimleri Dergisi | 2012

Anksiyete ile İlişkili Belleklerin Oluşumunda Bazolateral Amigdalanın Rolü

Elif Özen Akkurt; Sayad Kocahan; Emine Babar Melik; Enver Melik


Turkiye Klinikleri Tip Bilimleri Dergisi | 2012

Investigation of Changes in Anxiety and Learning Behavior During Oestrous Cycle in the Rat

Kübra Akillioğlu; Sayad Kocahan; Emine Babar Melik; Enver Melik

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