ADVANCES IN COGNITIVE SCIENCE
Year:2005 | Volume:7 | Issue:2|Papers Count:21

Objective: Regarding the involvement of potassium and calcium channel and / or GABAB receptors in the pathogenesis of depression, the effects of glibenclamide (potassium channel blocker), amlodipine (calcium channel blocker) and baclofen (GABAB agonist) on the efficacy of the two antidepressant drugs (amitriptyline and fluoxetine) were investigated in forced swimming test in mice as a model for depression. Method: This investigation is an experimental study. Forced swimming test was applied as a model for depression; the immobility time was considered as an indicator of depression of animal. In the present study the effects of glibenclamide, amlodipine and baclofen on antidepressant effects of amitriptyline and fluoxetine were evaluated. Next, the effects of glibenclamide, amlodipine and baclofen on antidepressant effects of amitriptyline and fluoxetine were studied. Results: Our data showed that neither glibenclamide nor amlodipine altered the immobility time and neither influenced the antidepressant response of amitriptyline and fluoxetine. In the second set of experiments, administration of a higher dose of baclofen decreased immobility time, while low doses of baclofen did not have a significant effect. Furthermore, administration of different doses of baclofen enhanced the antidepressant effects induced by amitriptyline, while coadministration of baclofen and fluoxetine decreased the antidepressant effects of fluoxetine. Conclusion: GABAB receptors play a dual role in the antidepressant responses of amitriptyline and fluoxetine.

Objective: Hippocampus is one of the principal reward – dependent learning centers. Regarding the high density of muscarinic receptors in the CA1 area of dorsal hippocampus, these receptors are likely to be involved in reward-dependent learning. In the present study, the effects of stimulation and / or inhibition of muscarinic receptors in dorsal hippocampus on morphine reward was investigated in male Wistar rats, using the method of Conditioned Place Preference (CPP). Method: This study was conducted with an experimental method. All animals weighing 200-240 g were bilaterally cannulated in the CA1 area of dorsal hippocampus by a stereotaxic instrument. Each animal was allowed to recover 1-week before CPP processing. A 5-day schedule for CPP was used with three distinct phases: the preconditioning phase, the conditioning phase, which lasted three days, and the testing or expression phase. Results: The subcutaneous (S.C.) administration of different doses of morphine sulphate (0.5-7 mg/kg) using a 3-day conditioning and unbiased method induced dose-related CPP. Intra-CA1 administration of different doses of physostigmine (anticholinesterase) and atropine (muscarinic antagonist) significantly potentiated and inhibited the morphine induced CPP respectively. Intra-CA1 administration of atropine reversed the potentiation induced by physostigmine in response to morphine. Conclusion: The single intra-CA1 administration of either physostigmine or atropine alone, did not induce a significant place preference or aversion. It may be concluded that the muscarinic receptors of the CA1 regions of dorsal hippocampus play an important role in morphine reward.

Objective: Given that phonological knowledge is highly effective in early reading acquisition, the aim of this study was to determine whether phonological awareness training for mentally retarded children could affect their reading skills. Method: In an interventional study, a control and an experimental group, each comprising 30 second grade primary schoolchildren with equal phonological knowledge, were recruited from Rajaieh special school for mentally retarded children. First, tests of phonological awareness as well as rate and accuracy of reading were carried out. Then, both groups received reading instruction for three months. During the same period, the experimental group received 20-hour phonological awareness training in addition to reading instruction. After three months both groups were re-assessed using the same tests. Results: Phonological awareness scores rose significantly in both groups after three months. Nevertheless, there was a higher rise in the experimental group. Also, the scores for accuracy and rate of reading increased non-significantly in both groups. Total phonological awareness score showed a significant correlation with accuracy and rate of reading. Conclusion: Regarding the results obtained in the study, providing reading instructions to mentally retarded children can cause an increase in the phonological awareness score as well as their reading rate and accuracy.

Objective: This research aimed to explore the words related to the subjects of “emotion” and “cognition” regarding their pleasant/ unpleasant, somatic/non-somatic and common/uncommon ratios in Farsi dictionaries (Moeen, Amid and Moaser). Method: the sample under study comprised all entries in the mentioned dictionaries. These entries were investigated by three independent judges (all psychologists) for their descriptive and qualitative characteristics. The final judgements benefited from linguistic feedback produced by a specialist in this field. Results: The target psychological components (emotion and cognition) in this study were significantly different from one another. Conclusion: The findings will be theoretically discussed from psychological and cultural points of view.

Objective: To assess the reliability of the Substance Abuse Module of a Persian translation of Composite International Diagnostic Interview (CIDI), in a multi-center study in Iran. Method: the sample consisted of 101 inpatients and outpatients from five psychiatric hospitals in Tehran. Trained psychologists conducted the interviews. The completed CIDI was administered to 65 subjects and CIDI-substance abuse module (CIDI-SAM) was administered to 36 others. To study the test-retest reliability, a second interview by a different person was administered to all subjects within 3 to 7 days of the first interview. Kappa and Yule’s statistics were used to evaluated reliability. Results: Overall, the reliability of substance disorder diagnosis was higher for complete CIDI than for CIDI-SAM. In complete CIDI in both diagnostic systems of ICD-10 and DSM-IV, Kappa statistics was 0.5 or higher with a generally higher Yule’s statistics; and opioid dependency had the highest kappa (0.64) among different disorders. In CIDI-SAM, the highest reliability regarding Kappa and Yule results was related to cannabis dependency (Kappa= 0.41; Yule= 0.6). Conclusion: Overall, the reliability of complete CIDI for the diagnosis of substance abuse disorders was better than CIDI-SAM. Weak reliability, especially in the Substance Abuse Module, may be due to the method of sampling or the high prevalence of the disorder.

Objective: Delayed discounting pracedure is the process through which the value of rewards and punishments decrease as a function of deferral. In addition to the introduction of two Farsi versions of an assessment test for this process, the results of the administration of the mentioned versions to different age groups are assessed.Method: Three groups including a group of 109 medical students (81 males), a group of 74 high school male students, and another group of 83 high school male students were assessed with two different methods (the continuously decreasing questionnaire method or the standard method, and the distributed questionnaire method or the random method). For the first two groups the continuously decreasing questionnaire method or the standard method, and for the third group the distributed questionnaire method or the randomized method were used. Results: Delayed discounting behavior in all three groups follows a hyperbolic logic. Delayed discounting equation in the standard method was 60% for male university students, 58% for female university students and 82% in high school students with no significant difference; but the same equation was 0.336 in the randomized method, which was significantly different from the results obtained in the standard method. Conclusion: In case the same methods of questioning are applied, delayed discounting equation (in the age limit under study) will not show any significant difference. But changing the questioning method and decreasing the pressure exerted on the subject to choose the breaking point leads to an increased reduction in the value of rewards with time.

Objective: To determine the prevalence of depression in patients undergoing hemodialysis and to determine the risk factors for depression in these patients, in order to suggest prophylactic and therapeutic interventions. Method: the subjects in this cross-sectional study consisted of 80 patients (48 men, 32 women) with chronic renal failure, undergoing hemodialysis. Patients were selected using convenience sampling. The tools used in this study included a demographic questionnaire, Beck Depression Inventory (BDI), and DSM-IV questionnaire for Major Depressive Disorder and Dysthymic Disorder. Results: According to BDI 60% of patients had depression. Also, the DSM-IV questionnaire showed that 22.5% and 30% of patients suffered from major depressive disorder and dysthymic disorder respectively. There was also a significant correlation between depression and diabetes mellitus. Conclusion: Regarding the high prevalence of depression among dialysis patients in general and patients with diabetic nephropathy in particular, more extensive studies on this issue as well as the assessment of depression in all dialysis patients and the involvement of psychiatrists in dialysis centers is recommended.

Objective: To survey the relationship between happiness and personality in the literature. Method: Review of literature. Results and conclusion: Happiness is related to cognitive, social, emotional and physical dimensions of personality. In the cognitive dimension, internal control, optimism, goal-striving and creativity have positive correlation with happiness. In the social dimension extraversion, altruism, agreeableness and positive relationships with others have positive correlation with happiness. In the emotional dimension emotional stability, self-esteem and self-efficacy are related to happiness, and in the physical dimension a healthy immune system and happiness are related.