Vafaei Aa, Rashidy-Pour A,
Volume 67, Issue 4 (7-2009)
Abstract
Background: Previous studies suggested that stressful events that release Glucocorticoid from adrenal cortex and also injection of agonists of glucocorticoids receptors probably affect emotional learning and memory process and modulate them. The aim of this study was to determine the effects of acute stress and systemic injection of Corticosterone (as agonist of glucocorticoid receptors) on acquisition (ACQ), consolidation (CONS) and retrieval (RET) of emotional memory in rat.
Methods: In this experimental study we used 180 male Wistar rats (220-250). At the first rats was training in one trial inhibitory avoidance task. On the retention test given 48 h after training, the latency to re-enter the dark compartment of the apparatus (Step-through latency, STL) and the time spent in light chamber (TLC) were recorded during 10 min test. Intraperitoneal corticosterone in doses of 0.5, 1 and 3mg/kg injected 30min before, immediately after instruction and 30min before retrieval test. Also some groups received 10min stressful stimulation by restrainer at the same time. At the end locomotor's activity was measured for all animals.
Results: The data indicated that administration of corticosterone 30min before ACQ (1mg/kg), and immediately after CONS (1, 3mg/kg) enhance and 30min before RET (1, 3mg/kg) impair emotional memory (p<0.05). Acute stress impaired emotional memory in all phases (p<0.05). Also acute stress and injection of Corticosterone have not significantly affect motor activity.
Conclusions: These findings show that Glucocorticoid receptors in activation dependently plays an important role in modulation of emotional spatial memory processes (ACQ, CONS and RET in new information) for emotional events and these effects varies in different phases.
Abotalebi-Chaleshtary M, Rashidy-Pour A, Vafaei Aa,
Volume 67, Issue 7 (10-2009)
Abstract
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Background: Ample evidence indicated that
glucocorticoids, when administered after training, enhance memory consolidation
in a variety of tasks. The mechanisms underlying the enhancing effects of
glucocorticoids on memory consolidation are not well known. The aim of this
study was to determine the role of NMDA
receptors and calcium channels in glucocorticoid-induced enhancement of avoidance
memory consolidation in mice.
Methods: Experiments
were performed on 166 male albino mice (about 30gr).
The animals were trained in an inhibitory avoidance (IA) task
(0.5mA shock for 3
seconds). In Experiment 1, dose- response effects of corticosterone on
memory consolidation were determined. Immediately after training in IA task,
the animals were received different doses of corticosterone (0.3, 1 or 3mg/kg).
In Experiments 2 and 3,
effects of corticosterone on memory consolidation were examined in the presence
or absence of verapamil, a calcium channel blocker, (2.5, 5 or 20mg/kg)
or MK-801, an antagonist of NMDA
receptor (0.1mg/kg), respectively. In all experiments, retention
test was done two days later.
Results: Results
from first experiment revealed that corticosterone at dose of 0.3mg/kg
significantly improved consolidation of avoidance. Data from experiments 2 and 3
showed that both verapamil, in doses of 2.5 and 5mg/kg,
and MK801 significantly blocked corticosterone-induced enhancement
of memory consolidation.
Conclusion: Finding of this study clearly
demonstrated that the memory enhancing effects of corticosterone, at least in
part mediate via calcium channels and NMDA receptors.
Azamsadat Mousavi , Mojgan Karimi-Zarchi , Nadereh Behtash , Mahnaz Mokhtari-Gorgani , Nili Mehrdad , Mitra Rouhi , Seyedhossein Hekmatimoghaddam,
Volume 72, Issue 4 (7-2014)
Abstract
Background: The aim of this study was to assess the role of consolidative intraperito-neal chemotherapy with carboplatin in decreasing relapse and increasing survival in advanced epithelial ovarian cancers, as well as evaluation of its toxicity.
Methods: In this clinical trial 30 patients with epithelial ovarian cancer in stages II-IV who had complete surgery (optimal debulking surgery) received six standard cycles of intravenous carboplatin and paclitaxel. They were enrolled through non-random se-quential selection. The control patients were similar to case group in stage (II-IV) and pathology (epithelial ovarian cancer). The control group was evaluated retrospectively through hospital files. This clinical trial performed in Gynecology Oncology department in Tehran Valiasr University Hospital, during 2005-2010. They including 18 cases as the intervention group receiving intraperitoneal chemotherapy and 12 patients as the control group with only retrospective follow-up. The cases received 3 cycles of 400 mg/m2 intraperitoneal carboplatin every 21 days following intravenous chemotherapy. Relapse of disease was diagnosed as increasing or even doubling CA125 serum titer during one month, or any CA125 above 100 IU, or an abdominal or pelvic mass in ul-trasound or physical exam. Mean survival of two and five years, progression-free inter-val (PFI), overall survival (OS), relapse, demographic parameters, drug toxicities, path-ologic types of cancers in two groups were coded and compared using SPSS 14. Any P<0.05 was considered as a significant difference.
Results: The mean ages of cases and controls were 52.4±8.6 and 55.1±11.5 years. The mean duration of relapse-free survival was 13±8.6 months for the cases and 9.5±4.3 months for the control patients (not statistically different, P>0.05). The mean overall survival for cases and controls were 39±16.5 and 30.8±16.2 months, respectively (no significant difference, P>0.05). The frequency of drug toxicities in the cases was 5.6%, and consisted of mild-to-moderate abdominal pain, nausea and vomiting.
Conclusion: It seems that consolidation therapy with intraperitoneal carboplatin may not increase overall survival, reduce relapse rate or decrease mortality, though it does not induce considerable side effects. Since the mean survival in the intervention group was nine months more than controls, this difference may be clinically significant.
