Calismamizin amaci sporun merkezi sinir sistemi otonom aktivite duzeyinin gostergesi olan emosyon... more Calismamizin amaci sporun merkezi sinir sistemi otonom aktivite duzeyinin gostergesi olan emosyonel terlemeyi etkileyip etkilemedigini arastirmaktir. Bu hipotezi test edebilmek icin; emosyonel terleme duzeyi ve parametreleri, elektrodermal aktivite olcum yontemi ile belirlendi. Calisma aktif spor yapan (n=20) ve sedanter yasayan (n=20) toplam 40 gonullu ile yapildi. Gonulluler 18 ve 25 (ortalama 22 ± 0,45) yaslar arasinda, erkek, en az lise mezunu, herhangi bir saglik problemi olmayan, sigara veya bir baska bagimlilik yapan madde kullanmayan saglikli bireylerden secildi. Elektrodermal aktivite, ekzosomatik yontem kullanilarak, egzersizden once ve sonra gozler acik olmak uzere iki ayri kosulda kaydedildi. Tonik elektrodermal aktivite kaydin baslangicindaki ilk 120 saniyelik surede, fazik elektrodermal aktivite kaydi ise, uyari iintervalleri bilgisayar sistemi tarafindan rastgele secildigi icin deneyden deneye degisim gosterip (en az 10- en cok12dk.) geri kalan surede yapildi. Fazik e...
Since neurotoxicity of aluminium (Al) resembles the progressive neurodegeneration observed in Alz... more Since neurotoxicity of aluminium (Al) resembles the progressive neurodegeneration observed in Alzheimer Disease (AD), Al administration in several ways has been used to produce AD model. Intraperitoneal (ip) low dose (4.2 mg/ kg) Al injection in rats for long periods is the preferred method by some researchers. In this paper, the efficiency of this method for producing an AD model was evaluated. In this study, we looked at the neuropathology of Al and the characteristic lesions of AD by histological and immunohistochemical techniques and determined oxidative stress markers in the brains of Al-treated and control rats. We also made electrophysiological recordings at the hippocampus and evaluated possible behavioural changes by Morris water maze test. However, no pathologic changes occurred in the animals except for an impairment in long-term potentiation (LTP) in the hippocampus (e.g. the LTPs of population spike (PS) amplitude at 15 min post-tetanus were measured as 217±27% in Al-treated rats and as 240±42% in sham-treated rats, of baseline PS amplitude). According to the findings of the present study, low dose of ip Al in rats is not sufficient to produce a good AD model. Higher doses (≥10 mg/kg) should be used.
Carnosine is co-localized in glutamergic terminals and may be released together with glutamate. C... more Carnosine is co-localized in glutamergic terminals and may be released together with glutamate. Carnosine is a selective inhibitor of NO-dependent activation of guanylate cyclase (GC). Nitric oxide (NO) is known to affect the synaptic plasticity in the brain via the cGMP-dependent protein kinase pathway. Nitric oxide can be released from its donor sodium nitroprusside (SNP), and GC activity might be stimulated by SNP in a concentration-dependent manner. In our previous study, we found that microinfusions of 10 mg carnosine decreased long-term potentiation (LTP) in the rat dentate gyrus in vivo; it was supposed that carnosine decreased LTP via inhibition of soluble GC. We aimed at examination of interaction between SNP and carnosine in the course of hippocampal-dependent learning in rats. Effects of infusions of artificial cerebrospinal fluid (aCSF), 0.9 µg SNP, 10 µg carnosine, and 10 μg carnosine + 0.9 μg SNP into the dentate gyrus of rats were compared. The medial perforant path was subjected to high-frequency stimulation (HFS, 100 sec-1 , 1 sec). While the SNP-infused group of animals demonstrated higher population spike (PS) amplitudes than the carnosine and carnosine + SNP groups, there was no significant difference between the SNP and aCSF (control) groups. Thus, SNP induced more intense LTP, while carnosine reduced this process. When these drugs were administered in combination, PS amplitudes reduced with carnosine were partly increased with SNP. This increment was insignificant at the SNP dose used. Therefore, SNP did not prevent an inhibitory effect of carnosine on LTP. We consider that the inhibitory effect of carnosine in relatively low doses cannot be explained by its inhibitory influence on soluble GC.
S285 fathers, but may be linked to reduced quality of spermatocytes due to epigenetic modificatio... more S285 fathers, but may be linked to reduced quality of spermatocytes due to epigenetic modifications or accumulating genetic deficits, i.e. mutations, as a consequence of 'copy errors' during cell division, as recently suggested.
Introduction: One of the central features of the depressive psychopathology is a persistent ponde... more Introduction: One of the central features of the depressive psychopathology is a persistent pondering on negative thoughts and feelings, which is labeled as rumination. As a mode of responding to predominantly negative experiences it is going along with strong self-referential attention and amplifies the depressive mood by activating self-referential negative memories, feelings and experiences [1]. It further interferes with effective problem solving leading to often noticeable deficits in cognitive control processes. In our previous fMRI study with healthy controls we identified a brain network consisting of the posterior (PCC) and rostral anterior cingulate cortex (rACC) as well as ventromedial prefrontal cortex (VMPFC), which was related to the self-referential processing (SRP). The rostral ACC activation during negative SRP interfered with the 'cognitive' fronto-cingulate brain network during processing of the Stroop task. In the present study we sought to investigate the neural correlates of the enhanced self-referential processing and its impact on cognitive control processes in patients with Major Depressive Disorder (MDD). We hypothesized stronger BOLD signal in the rACC/VMPFC during processing of negative selfreferential stimuli, which goes along with abnormal frontocingulate activation during cognitive control in patients with MDD. Methods: 20 patients meeting DSM-IV criteria for MDD and 20 healthy controls matched for age and gender were included in the study. Negative, positive and neutral self-referential stimuli and the Stroop task were presented in an event-related design. Subjects were asked to judge the self-referential statements as to whether they properly described the participants themselves. Statistical analyses as implemented in SPM8 were used to investigate the neural correlates of the abnormal SRP and cognitive control processes in patients. Results: As expected we observed a significant between-group difference in the judgments of the negative and positive, but not of the neutral self-referential statements. Patients showed a slower overall performance in the Stroop task compared to healthy controls. Regarding the brain activation we observed in controls significantly higher rACC/VMPFC activation during negative compared to neutral SRP stimuli, which was not detected in patients. This result was statistically confirmed by the GROUP (controls vs. patients) × VALENCE (negative vs. neutral SRP) interaction. We further observed a significant interaction in the amygdala, hippocampus and putamen, indicating a higher BOLD signal in these regions in patients than controls during neutral compared to the negative SRP condition. In the Stroop task a significantly stronger activation was detected in the frontocingulate network in healthy controls. Conclusions: Contrary to our initial hypothesis we did not observe relative hyperactivity in the rACC/VMPFC, in a brain area, which was considered to play a major role in the psychopathology of MDD. This observation might be based on the inability of depressed patients to flexibly up-and down-regulate the activity in this region as observed in controls. Patients may exhibit chronic hyperactivity, when exposed to the self-referential stimuli due to the triggering of ruminative processes. These in turn interferes with concurrent cognitive control processes leading to a decrease in activation in the fronto-cingulate brain regions, representing neuroanatomically the core network of the cognitive control.
Purpose: The aim of the study was to explore whether matrix metalloproteinases (MMPs) is a requis... more Purpose: The aim of the study was to explore whether matrix metalloproteinases (MMPs) is a requisite for efficient hippocampal-dependent learning in the perforant pathway/dentate gyrus synapses. With this aim, we infused FN-439 which is a MMPs inhibitor into the ...
WOS:000360810100272The goal of this study was to evaluate whether sodium selenite could afford pr... more WOS:000360810100272The goal of this study was to evaluate whether sodium selenite could afford protection against the effects of hypothyroidism on long-term potentiation (LTP), which is thought to be the cellular basis for learning and memory. Hypothyroidism was induced in young-adult rats by the administration of 6-n-propyl-2-thiouracil (PTU) in tap water for 21 days. Half of these hypothyroid and euthroid rats were given 10 ppM selenium with their drinking water. Field potentials were recorded from the dentate gyrus in response to stimulation of the medial perforant pathway in vivo. PTU treatment resulted in a significant reduction in both free T3 and free T4 levels, whereas selenium administration to PTU-treated rats restored only the levels of free T3 to their control values. Thyroid hormone levels were not affected by selenium in euthyroid rats. PTU-treated rats exhibited an attenuation of population spike (PS) – LTP, but a comparable potentiation of excitatory postsynaptic potential (EPSP) was found among these rats. The administration of selenium to PTU-treated rats was partially able to attenuate impairment of LTP, but not of potentiation during the LTP induction protocol in hypothyroid rats. Interestingly, the hypothyroid rats that were supplemented with selenium had a lower EPSP potentiation during induction protocol than the control rats. The present study suggests a possible importance of T3 in Se-induced rescue of impaired PS-LTP in hypothyroidism
Purpose: The goal of the present study was to assess the effect of stimuli predictability on pres... more Purpose: The goal of the present study was to assess the effect of stimuli predictability on presaccadic cortical potentials. Material and Methods: In the present study, two scalp potentials recorded prior to saccades in relation to visual targets (the presaccadic negativity [PSN] and the presaccadic positivity [PSP]) were studied in ten healthy subjects, performing visually guided horizontal saccades in darkness. Presaccadic potetials from Fz, Cz electrode sites and eye movements from external canthi were recorded as simultaneously. Two interstimulus intervals (ISI) (regular 6 sec, and irregular 3 – 9sec) were used to exemine the differences in presaccadic activity under different conditions (predictable [P] vs unpredictable [UP] conditions). The technique of back-averaging from the onset of saccade was applied and separate wave forms were obtained for both conditions in each subject. Results: A slow negative shift began approximately 1200 msec before eye movement in UP condition, and 950 msec in P condition. The difference was statistically significant. The integral over presaccadic negativity was significantly greater for UP condition at the Fz and Cz location than in P condition. There was no significant differences between UP and P conditions when compared the onset time or amplitude of the PSP. Conclusion: These results support the hypothesis that presaccadic negativity is related to non-specific processes such as attention, arousal, motivation or volitional effort, rather than specific processes. However, our findings do not exclude the role of presaccadic programming, reflecting activity of the cotical eye fields on presaccadic cortical activity.
Uyku, ogrenme ve bellek sureclerinin birbiriyleiliskili oldugunu ve REM uyku yoksunlugunun ogrenm... more Uyku, ogrenme ve bellek sureclerinin birbiriyleiliskili oldugunu ve REM uyku yoksunlugunun ogrenmesureclerini olumsuz etkiledigini bildiren cok sayidacalisma vardir. Ancak, bu calismalarin sonuclariarasinda celiskiler bulunmaktadir. Bu nedenle bucalismada genc eriskin erkek sicanlarda uzun sureliREM uyku yoksunlugunun ogrenme ve bellek uzerineolan etkisine aciklik getirilmesi amaclandi. Calisma; 8aylik Wistar Albino cinsi 30 adet erkek sicanla; uykuyoksunlugu (UY) (n=10), ortam kontrol (OK) (n=10)ve kafes kontrol (KK) (n=10) gruplari olusturularakgerceklestirildi. Uyku yoksunlugu grubundaki sicanlar21 gun sureyle her gun 18 saat boyunca; 14 adet darplatform iceren su tanki seklindeki duzenektebarindirilarak uyanik birakildilar. Ortam kontrolgrubu sicanlar ayni sure ile genis platformlu su tankiduzeneginde, kafes kontrol grubu sicanlarda standartsican kafeslerinde barindirildi. Uyku yoksunluguuygulamalari sonunda Morris su tankinda ogrenme vebellek degerlendirildi. Degerlendirmede ku...
Calismamizin amaci sporun merkezi sinir sistemi otonom aktivite duzeyinin gostergesi olan emosyon... more Calismamizin amaci sporun merkezi sinir sistemi otonom aktivite duzeyinin gostergesi olan emosyonel terlemeyi etkileyip etkilemedigini arastirmaktir. Bu hipotezi test edebilmek icin; emosyonel terleme duzeyi ve parametreleri, elektrodermal aktivite olcum yontemi ile belirlendi. Calisma aktif spor yapan (n=20) ve sedanter yasayan (n=20) toplam 40 gonullu ile yapildi. Gonulluler 18 ve 25 (ortalama 22 ± 0,45) yaslar arasinda, erkek, en az lise mezunu, herhangi bir saglik problemi olmayan, sigara veya bir baska bagimlilik yapan madde kullanmayan saglikli bireylerden secildi. Elektrodermal aktivite, ekzosomatik yontem kullanilarak, egzersizden once ve sonra gozler acik olmak uzere iki ayri kosulda kaydedildi. Tonik elektrodermal aktivite kaydin baslangicindaki ilk 120 saniyelik surede, fazik elektrodermal aktivite kaydi ise, uyari iintervalleri bilgisayar sistemi tarafindan rastgele secildigi icin deneyden deneye degisim gosterip (en az 10- en cok12dk.) geri kalan surede yapildi. Fazik e...
Since neurotoxicity of aluminium (Al) resembles the progressive neurodegeneration observed in Alz... more Since neurotoxicity of aluminium (Al) resembles the progressive neurodegeneration observed in Alzheimer Disease (AD), Al administration in several ways has been used to produce AD model. Intraperitoneal (ip) low dose (4.2 mg/ kg) Al injection in rats for long periods is the preferred method by some researchers. In this paper, the efficiency of this method for producing an AD model was evaluated. In this study, we looked at the neuropathology of Al and the characteristic lesions of AD by histological and immunohistochemical techniques and determined oxidative stress markers in the brains of Al-treated and control rats. We also made electrophysiological recordings at the hippocampus and evaluated possible behavioural changes by Morris water maze test. However, no pathologic changes occurred in the animals except for an impairment in long-term potentiation (LTP) in the hippocampus (e.g. the LTPs of population spike (PS) amplitude at 15 min post-tetanus were measured as 217±27% in Al-treated rats and as 240±42% in sham-treated rats, of baseline PS amplitude). According to the findings of the present study, low dose of ip Al in rats is not sufficient to produce a good AD model. Higher doses (≥10 mg/kg) should be used.
Carnosine is co-localized in glutamergic terminals and may be released together with glutamate. C... more Carnosine is co-localized in glutamergic terminals and may be released together with glutamate. Carnosine is a selective inhibitor of NO-dependent activation of guanylate cyclase (GC). Nitric oxide (NO) is known to affect the synaptic plasticity in the brain via the cGMP-dependent protein kinase pathway. Nitric oxide can be released from its donor sodium nitroprusside (SNP), and GC activity might be stimulated by SNP in a concentration-dependent manner. In our previous study, we found that microinfusions of 10 mg carnosine decreased long-term potentiation (LTP) in the rat dentate gyrus in vivo; it was supposed that carnosine decreased LTP via inhibition of soluble GC. We aimed at examination of interaction between SNP and carnosine in the course of hippocampal-dependent learning in rats. Effects of infusions of artificial cerebrospinal fluid (aCSF), 0.9 µg SNP, 10 µg carnosine, and 10 μg carnosine + 0.9 μg SNP into the dentate gyrus of rats were compared. The medial perforant path was subjected to high-frequency stimulation (HFS, 100 sec-1 , 1 sec). While the SNP-infused group of animals demonstrated higher population spike (PS) amplitudes than the carnosine and carnosine + SNP groups, there was no significant difference between the SNP and aCSF (control) groups. Thus, SNP induced more intense LTP, while carnosine reduced this process. When these drugs were administered in combination, PS amplitudes reduced with carnosine were partly increased with SNP. This increment was insignificant at the SNP dose used. Therefore, SNP did not prevent an inhibitory effect of carnosine on LTP. We consider that the inhibitory effect of carnosine in relatively low doses cannot be explained by its inhibitory influence on soluble GC.
S285 fathers, but may be linked to reduced quality of spermatocytes due to epigenetic modificatio... more S285 fathers, but may be linked to reduced quality of spermatocytes due to epigenetic modifications or accumulating genetic deficits, i.e. mutations, as a consequence of 'copy errors' during cell division, as recently suggested.
Introduction: One of the central features of the depressive psychopathology is a persistent ponde... more Introduction: One of the central features of the depressive psychopathology is a persistent pondering on negative thoughts and feelings, which is labeled as rumination. As a mode of responding to predominantly negative experiences it is going along with strong self-referential attention and amplifies the depressive mood by activating self-referential negative memories, feelings and experiences [1]. It further interferes with effective problem solving leading to often noticeable deficits in cognitive control processes. In our previous fMRI study with healthy controls we identified a brain network consisting of the posterior (PCC) and rostral anterior cingulate cortex (rACC) as well as ventromedial prefrontal cortex (VMPFC), which was related to the self-referential processing (SRP). The rostral ACC activation during negative SRP interfered with the 'cognitive' fronto-cingulate brain network during processing of the Stroop task. In the present study we sought to investigate the neural correlates of the enhanced self-referential processing and its impact on cognitive control processes in patients with Major Depressive Disorder (MDD). We hypothesized stronger BOLD signal in the rACC/VMPFC during processing of negative selfreferential stimuli, which goes along with abnormal frontocingulate activation during cognitive control in patients with MDD. Methods: 20 patients meeting DSM-IV criteria for MDD and 20 healthy controls matched for age and gender were included in the study. Negative, positive and neutral self-referential stimuli and the Stroop task were presented in an event-related design. Subjects were asked to judge the self-referential statements as to whether they properly described the participants themselves. Statistical analyses as implemented in SPM8 were used to investigate the neural correlates of the abnormal SRP and cognitive control processes in patients. Results: As expected we observed a significant between-group difference in the judgments of the negative and positive, but not of the neutral self-referential statements. Patients showed a slower overall performance in the Stroop task compared to healthy controls. Regarding the brain activation we observed in controls significantly higher rACC/VMPFC activation during negative compared to neutral SRP stimuli, which was not detected in patients. This result was statistically confirmed by the GROUP (controls vs. patients) × VALENCE (negative vs. neutral SRP) interaction. We further observed a significant interaction in the amygdala, hippocampus and putamen, indicating a higher BOLD signal in these regions in patients than controls during neutral compared to the negative SRP condition. In the Stroop task a significantly stronger activation was detected in the frontocingulate network in healthy controls. Conclusions: Contrary to our initial hypothesis we did not observe relative hyperactivity in the rACC/VMPFC, in a brain area, which was considered to play a major role in the psychopathology of MDD. This observation might be based on the inability of depressed patients to flexibly up-and down-regulate the activity in this region as observed in controls. Patients may exhibit chronic hyperactivity, when exposed to the self-referential stimuli due to the triggering of ruminative processes. These in turn interferes with concurrent cognitive control processes leading to a decrease in activation in the fronto-cingulate brain regions, representing neuroanatomically the core network of the cognitive control.
Purpose: The aim of the study was to explore whether matrix metalloproteinases (MMPs) is a requis... more Purpose: The aim of the study was to explore whether matrix metalloproteinases (MMPs) is a requisite for efficient hippocampal-dependent learning in the perforant pathway/dentate gyrus synapses. With this aim, we infused FN-439 which is a MMPs inhibitor into the ...
WOS:000360810100272The goal of this study was to evaluate whether sodium selenite could afford pr... more WOS:000360810100272The goal of this study was to evaluate whether sodium selenite could afford protection against the effects of hypothyroidism on long-term potentiation (LTP), which is thought to be the cellular basis for learning and memory. Hypothyroidism was induced in young-adult rats by the administration of 6-n-propyl-2-thiouracil (PTU) in tap water for 21 days. Half of these hypothyroid and euthroid rats were given 10 ppM selenium with their drinking water. Field potentials were recorded from the dentate gyrus in response to stimulation of the medial perforant pathway in vivo. PTU treatment resulted in a significant reduction in both free T3 and free T4 levels, whereas selenium administration to PTU-treated rats restored only the levels of free T3 to their control values. Thyroid hormone levels were not affected by selenium in euthyroid rats. PTU-treated rats exhibited an attenuation of population spike (PS) – LTP, but a comparable potentiation of excitatory postsynaptic potential (EPSP) was found among these rats. The administration of selenium to PTU-treated rats was partially able to attenuate impairment of LTP, but not of potentiation during the LTP induction protocol in hypothyroid rats. Interestingly, the hypothyroid rats that were supplemented with selenium had a lower EPSP potentiation during induction protocol than the control rats. The present study suggests a possible importance of T3 in Se-induced rescue of impaired PS-LTP in hypothyroidism
Purpose: The goal of the present study was to assess the effect of stimuli predictability on pres... more Purpose: The goal of the present study was to assess the effect of stimuli predictability on presaccadic cortical potentials. Material and Methods: In the present study, two scalp potentials recorded prior to saccades in relation to visual targets (the presaccadic negativity [PSN] and the presaccadic positivity [PSP]) were studied in ten healthy subjects, performing visually guided horizontal saccades in darkness. Presaccadic potetials from Fz, Cz electrode sites and eye movements from external canthi were recorded as simultaneously. Two interstimulus intervals (ISI) (regular 6 sec, and irregular 3 – 9sec) were used to exemine the differences in presaccadic activity under different conditions (predictable [P] vs unpredictable [UP] conditions). The technique of back-averaging from the onset of saccade was applied and separate wave forms were obtained for both conditions in each subject. Results: A slow negative shift began approximately 1200 msec before eye movement in UP condition, and 950 msec in P condition. The difference was statistically significant. The integral over presaccadic negativity was significantly greater for UP condition at the Fz and Cz location than in P condition. There was no significant differences between UP and P conditions when compared the onset time or amplitude of the PSP. Conclusion: These results support the hypothesis that presaccadic negativity is related to non-specific processes such as attention, arousal, motivation or volitional effort, rather than specific processes. However, our findings do not exclude the role of presaccadic programming, reflecting activity of the cotical eye fields on presaccadic cortical activity.
Uyku, ogrenme ve bellek sureclerinin birbiriyleiliskili oldugunu ve REM uyku yoksunlugunun ogrenm... more Uyku, ogrenme ve bellek sureclerinin birbiriyleiliskili oldugunu ve REM uyku yoksunlugunun ogrenmesureclerini olumsuz etkiledigini bildiren cok sayidacalisma vardir. Ancak, bu calismalarin sonuclariarasinda celiskiler bulunmaktadir. Bu nedenle bucalismada genc eriskin erkek sicanlarda uzun sureliREM uyku yoksunlugunun ogrenme ve bellek uzerineolan etkisine aciklik getirilmesi amaclandi. Calisma; 8aylik Wistar Albino cinsi 30 adet erkek sicanla; uykuyoksunlugu (UY) (n=10), ortam kontrol (OK) (n=10)ve kafes kontrol (KK) (n=10) gruplari olusturularakgerceklestirildi. Uyku yoksunlugu grubundaki sicanlar21 gun sureyle her gun 18 saat boyunca; 14 adet darplatform iceren su tanki seklindeki duzenektebarindirilarak uyanik birakildilar. Ortam kontrolgrubu sicanlar ayni sure ile genis platformlu su tankiduzeneginde, kafes kontrol grubu sicanlarda standartsican kafeslerinde barindirildi. Uyku yoksunluguuygulamalari sonunda Morris su tankinda ogrenme vebellek degerlendirildi. Degerlendirmede ku...
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