scholarly journals Effects of rivastigmine and memantine alone and in combination on learning and memory in rats with scopolamine-induced amnesia

Open Medicine ◽  
2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Peter Georgiev Yanev ◽  
Darinka Slavcheva Dimitrova ◽  
Damianka Peteva Getova-Spassova
Keyword(s):  
Passive Avoidance ◽  
Learning And Memory ◽  
Cholinesterase Inhibitors ◽  
Memory Retention ◽  
Single Drug ◽  
Impaired Memory ◽  
Avoidance Tests ◽  
Step Down ◽  
Conditioned Responses ◽  
Nmda Blockers

AbstractBackground: Cholinesterase inhibitors and glutamate blockers are commonly used for the treatment of cognitive impairment in Alzheimer’s disease. The aim was to evaluate the effects of rivastigmine and memantine alone or in combination in rats with scopolamine-impaired memory. Method: 5 groups of rats were used: control, scopolamine (model), model with rivastigmine, model with memantine, and model with both drugs. Active avoidance test was performed and the number of conditioned responses, unconditioned responses and intertrial crossing were recorded. Passive avoidance tests step-through with criteria latency of reaction 180 s in the light chamber and step-down with criteria latency of reaction 60 s on the platform were done. Results: Control rats learned the task and kept it on memory tests. Scopolamine treated rats failed to perform it. The rivastigmine, memantine and its combination groups showed increased CRs during learning and memory retention tests. In both passive avoidance tests an increased latency of reaction was observed in the drug treated groups. Conclusion: The combination of both drugs rivastigmine and memantine is more effective than the use of the single drug in cognitive impaired rats. Cholinesterase inhibitors and NMDA blockers may be combined in the treatment of different kind of dementias.

Effects of Rhodiola rosea extract on passive avoidance tests in rats

Open Medicine ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. 176-181 ◽  
Author(s):  
Damianka Getova ◽  
Anita Mihaylova
Keyword(s):  
Passive Avoidance ◽  
Learning And Memory ◽  
Memory Retrieval ◽  
Rhodiola Rosea ◽  
Learning Session ◽  
Brain Functions ◽  
Impaired Memory ◽  
Avoidance Tests ◽  
Step Down ◽  
Improved Performance

AbstractThe purpose was to evaluate the effects of extract of Rhodiola rosea on learning and memory processes on rats. The two series of experiments were carried out — on naïve rats and on rats with scopolamine-impaired memory. The passive avoidance tests were performed — step-down and step-through. The latency of reactions in seconds was observed in both tests. Naïve rats treated with the extract in showed the prolongation of latency of reaction of both step-down and step-through passive avoidances compared to the controls. Rats with scopolamine-impaired memory showed shorter latency of reaction in both passive avoidance tests compared to the controls. Rats treated with the extract of Rh. Rosea with scopolamine-impaired memory prolonged the latency in both passive avoidance tests compared to scopolamine group. It was found that the extract of Rh. Rosea improved performance during learning session, short and long memory retrieval tests in naïve rats. Scopolamine impaired the learning and memory retrieval of rats, but Rh. Rosea pretreatment improved performance and turned off the deterioration effect of scopolamine on these brain functions probably by non-specific mechanisms on cholinergic neurons. The studied plant extract can be a candidate for treatment of dementia and other memory disturbances.

scholarly journals Effect of Atorvastatin and Rosuvastatin on Learning and Memory in Rats with Diazepam-Induced Amnesia

Folia Medica ◽  
2013 ◽  
Vol 55 (2) ◽  
pp. 58-65 ◽  
Author(s):  
Maria T. Georgieva-Kotetarova ◽  
Ivanka I. Kostadinova
Keyword(s):  
Passive Avoidance ◽  
Active Avoidance ◽  
Long Term Memory ◽  
Term Memory ◽  
Avoidance Test ◽  
Avoidance Tests ◽  
Step Down ◽  
Conditioned Responses ◽  
Active Avoidance Test

ABSTRACT During the past decade, evidence has emerged that statins have neuroprotective effects. AIM: The aim of this study was to investigate the effects of atorvastatin and rosuvastatin on learning and memory in rats with diazepam-induced amnesia. MATERIAL AND METHODS: Experiments were carried out on 48 white male Wistar rats, divided into 6 groups, each of 8 rats. The experimental animals were treated per os for 14 days with atorvastatin and rosuvastatin in doses of 10 mg/kg and 20 mg/kg body weight, respectively. To induce amnesia diazepam was administered intraperitoneally in a dose of 2.5 mg/kg bw. Cognitive skills of the animals were examined after the induction of amnesia with active avoidance test using autonomic reflex conditioner (shuttle box) and passive avoidance tests (step-through and step down) (Ugo Basile, Italy). The following parameters were assessed: number of conditioned responses (avoidances), number of unconditioned responses (escapes) and number of intertrial crossings in the active avoidance test; latency of reactions was measured in the passive avoidance tests. RESULTS: We found a significant increase of conditioned responses in atorvastatin treated animals (in a dose of 10 mg/kg bw) in active avoidance training. In the animals treated with rosuvastatin in both doses there was a statistically significant increase of unconditioned responses. In the step-through passive avoidance test there was significant improvement of short-term and long-term memory following administration of atorvastatin (10 mg/kg bw). Rosuvastatin (10 mg/kg bw) preserves long-term memory. In the step-down passive avoidance test, atorvastatin (10 mg/kg bw) and rosuvastatin (10 mg/kg bw and 20 mg/kg bw) preserve long-term memory. CONCLUSIONS: Atorvastatin (10 mg/kg bw) and rosuvastatin (10 mg/kg and 20 mg/kg bw) improve cognitive functions in rats with diazepam-induced amnesia and preserve longterm memory.

scholarly journals Cognitive-Enhancing Effect ofAronia melanocarpaExtract against Memory Impairment Induced by Scopolamine in Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hyeon Yong Lee ◽  
Jin Bae Weon ◽  
Youn Sik Jung ◽  
Nam Young Kim ◽  
Myong Ki Kim ◽  
...  
Keyword(s):  
Passive Avoidance ◽  
Learning And Memory ◽  
Morris Water Maze ◽  
Water Maze ◽  
Memory Impairment ◽  
Ache Activity ◽  
Antioxidant Effect ◽  
Enhancing Effect ◽  
Aronia Melanocarpa ◽  
Avoidance Tests

Aronia melanocarpa(A. melanocarpa)berriesare a fruit with a marked antioxidant effect. The objective of this study was to confirm the effect ofA. melanocarpa berriesextract against scopolamine-induced memory impairment in mice using the Morris water maze and passive avoidance test. Moreover, we determined a possible mechanism of the cognitive-enhancing effect involving AChE activity and BDNF and p-CREB expression in the hippocampus of mice.A. melanocarpa berriesextract attenuated the learning and memory impairment induced by scopolamine in the Morris water maze (79.3 ± 0.8 s of 200 mg/kg and 64.4 ± 10.7 s of 400 mg/kg on day 4) and passive avoidance tests (46.0 ± 41.1 s of 200 mg/kg and 25.6 ± 18.7 s of 400 mg/kg).A. melanocarpa berriesextract reduced the acetylcholinesterase level in the hippocampus of scopolamine-injected mice and increased BDNF and p-CREB expression in the hippocampus. The major compound, cyanidin-3-O-galactoside, also reversed memory impairment. These results showed thatA. melanocarpa berriesextract improved memory impairment by inhibiting AChE and increasing BDNF and p-CREB expression, and cyanidin-3-O-galactoside may be responsible for the effect ofA. melanocarpa berriesextract.

scholarly journals Effects of Long-Term Treatment with Atorvastatin and Rosuaastatin on Active Avoidance Test in Intact Rats

2013 ◽  
Vol 6 (1) ◽  
pp. 24-28
Author(s):  
Maria T. Georgieva-Kotetarova ◽  
Ivanka I. Kostadinova ◽  
Delian P. Delev
Keyword(s):  
Learning And Memory ◽  
Retention Test ◽  
Active Avoidance ◽  
Treated Group ◽  
Control Group ◽  
Memory Retention ◽  
Learning Session ◽  
Conditioned Responses ◽  
Vehicle Treated Group ◽  
Active Avoidance Test

Summary Statins are widely used for treatment of hyperlipidemia. They have been shown to possess pleiotropic effects apart from their lipid-lowering activity - anti-inflammatory, immunomodulatory, and neuroprotective. Most studies suggest that statins can protect the brain against damage but it is not clear whether they improve cognitive function in patients without neuropathy. The aim of the present study was to investigate the effect of 3-month treatment with atorvastatin and rosuvastatin on learning and memory processes in rats without brain damage. Wistar rats were treated orally for 90 days with atorvastatin and rosuvastatin at a dose of 10 mg/kg b. w. in parallel with the vehicle-treated group. After that period, learning ability and memory retention was evaluated using an active avoidance test - automatic reflex conditioner (shuttle box). The learning session was carried out on 5 consecutive days. Memory retention test was performed on day 12. The following behavioral reactions were investigated: conditioned responses (avoidance), unconditioned responses (escapes), and intertrial crossings. We found increased number of conditioned responses in groups, treated with atorvastatin 10 mg/kg b.w., and with rosuvastatin 10 mg/kg b.w. during the learning session and on the memory retention test, as compared to the same-day control group. The atorvastatin-treated group showed an increased number of unconditioned responses on days 1 and 2, as compared to the control group. In the group treated with Rosuvastatin there was an increased number of escapes on days 1,2 and 4, as compared to the vehicle-treated group. Atorvastatin and rosuvastatin at a dose of 10 mg/kg b.w. improved processes of learning and memory retention after the 3-month treatment.

Effects of GABAB receptor antagonists CGP63360, CGP76290A and CGP76291A on learning and memory processes in rodents

Open Medicine ◽  
2007 ◽  
Vol 2 (3) ◽  
pp. 280-293 ◽  
Author(s):  
Damianka Getova ◽  
Darinka Dimitrova
Keyword(s):  
Learning And Memory ◽  
Negative Reinforcement ◽  
Gabab Receptor ◽  
Memory Retention ◽  
Receptor Antagonists ◽  
Memory Processes ◽  
Chemical Structures ◽  
Avoidance Tests ◽  
Gabab Antagonists ◽  
Gabab Receptor Antagonists

AbstractData in literature that use methods for studying the learning and memory processes suggest that GABA and especially GABAB receptor antagonists may be active against amnesia. The aim of our study was to examine the effects of three new GABAB-antagonists on learning and memory processes. Active and passive avoidance tests with negative reinforcement in rats were used. The rats treated with different GABAB receptor antagonists showed improving effects in both tests (active and passive avoidances)on learning as well as on memory retention. There are some differences in their activities, probably due to its chemical structures. The phosphinic analogue CGP63360A is potent to the point that the benzoic one CGP76290A and the left isomer of the benzoic analogue CGP76291A has no effect. It may be concluded that the obtained results on the GABAB receptor antagonists could contribute to their pharmacological characteristics and might be of interest for potential clinical implication.

Effects of cholinesterase inhibitor metrifonate on naive rats and rats with a model of hypoxia-induced impaired memory

Open Medicine ◽  
2007 ◽  
Vol 2 (4) ◽  
pp. 430-446
Author(s):  
Darinka Dimitrova ◽  
Damianka Getova ◽  
Vesselin Belovezdov
Keyword(s):  
Passive Avoidance ◽  
Active Avoidance ◽  
Long Term Memory ◽  
Memory Retention ◽  
Short Term ◽  
Learning Session ◽  
Term Memory ◽  
Avoidance Test ◽  
Avoidance Tests

AbstractCholinesterase inhibitors are currently used in the therapy of different kind of dementia to improve brain memory functions. The acetylcholinesterase inhibitor metrifonate was studied in naive rats and in rats with a model of sodium nitrite-induced hypoxia. One active avoidance test and in two passive avoidance tests were used. In the active avoidance test metrifonate increased the number of avoidances during the learning session only. In both passive avoidance tests, metrifonate prolonged latency differently during the learning session and in short-term or in long-term memory retention. Hypoxic rats showed lower numbers of avoidances in learning and memory retention sessions. Metrifonate increased the number of avoidances during the learning session for hypoxic rats. In the step-through passive avoidance test, metrifonate increased the latency of reactions in the learning session and in long-term memory retention tests. In the step-down passive avoidance test, the groups with hypoxia and metrifonate did not change the latency of reaction in the learning and long-term memory retention sessions, but increased the latency of reactions in the short-term memory retention test. Morphological data showed a significant impaired neuronal structure in a CA1 zone of the hippocampus in hypoxic rats and a tendency to preserving in rats treated with metrifonate. Our results suggest that metrifonate improves cognitive functions in naive and in hypoxic rats.

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