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Universidade Federal de Santa Catarina Centro de Ciências Biológicas Programa de Pós-Graduação em Neurociências
| Content Provider | Semantic Scholar |
|---|---|
| Author | Eduardo, Luis Bettio, B. P. S. |
| Copyright Year | 2012 |
| Abstract | Introduction: The brain has a high metabolic rate, dependent on the mitochondrial respiratory chain. The respiratory chain consists of five enzymatic complexes distributed in the inner mitochondrial membrane and is one of the processes responsible for the synthesis of ATP. Mesial temporal lobe epilepsy with hippocampal sclerosis (ELTM-EH) is a common type of epilepsy often referred to surgical treatment. Interictal hypometabolism of the temporal lobe is commonly observed by functional neuroimaging on the side of MTLE-HS and has been associated with neuropsychological deficits. Metabolic energetics decreases in orbito-frontal regions is also identified in these patients with psychiatric comorbidities. However, the molecular mechanisms are still virtually not defined. Therefore, we here investigated the association between cognitive perfomance and psychiatric diagnoses of anxiety and depression and mitochondrial respiratory chain enzyme activities in samples collected from mesial temporal cortex, amygdala and hippocampus of these patients. Methods: The sample consisted of 32 individuals diagnosed with MTLE-HS refractory to drug treatment. These individuals were surgically treated for seizure control, where samples from the mesial temporal cortex, amygdala and hippocampus were removed. Patients were also submitted a neuropsychological and psychiatric evaluation before surgery. Multiple linear regression was performed to identify which mitochondrial enzymes in these three structures could predict the performance of each cognitive test. To investigate the association between enzyme activity and the psychiatric diagnosis of anxiety and depression, chi-square test was used to compare categorical variables and one–way ANOVA for continuous variables. When indicated, multiple regressions analysis was done to control clinical, biochemical and demographic imbalances between the groups. Results: There was some degree of association between mitochondrial respiratory chain complex enzyme activities at right temporal lobe structures and nonverbal declarative memory tests, as Rey-Osterrieth Complex Figure and Picture Completion, showing positive or negative associations depending on the brain structure, cognitive test and mitochondrial enzymes analyzed. Only one verbal memory and one language test (Logical Memory I and Category Fluency) were significantly (p ≤ 0,02) associated with mitochondrial respiratory chain complex enzyme activities from the left temporal lobe structures. There were no association between the mitochondrial enzymatic activities and the presence of psychiatric diagnosis (p ≥ 0,11). Conclusion: The activity of the mitochondrial respiratory chain enzymes from the right temporal lobe structures is strongly associated with some nonverbal memory tests scores, showing positive or negative association depending on the brain structure, cognitive test and mitochondrial enzyme analyzed. The association among specific verbalrelated cognitive tests and enzymatic activity in the dominant hemisphere is more complex and may be related to a less frequent lateralizing profile of cognitive performance observed in some populations of MTLE-HS patients. The absence of association between mitochondrial enzymatic activity and the psychiatric diagnosis in temporal lobe structures of these patients reinforces the idea that the pathophysiological mechanisms involved in these diagnoses result from an intricate interaction between neurobiological and psychosocial aspects. Key-words: Brain Metabolism, Cognition, Anxiety, Depression, Temporal lobe Epilepsy, Hippocampus. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repositorio.ufsc.br/bitstream/handle/123456789/183594/PGNC0275-T.pdf?isAllowed=y&sequence=-1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
