Passive avoidance test

The passive avoidance apparatus we use consists of two compartments, one (30 x 30 x 30 cm) brightly lit and the other (20 x 20 x 12.5) dark, connected by a small opening (8x8 cm) which can be closed by a guillotine door. 

For the first trial (Tl), rats are placed individually into the lighted compartment. After 30 seconds, the door to the dark compartment is opened. When the rat has entered the dark compartment, the door is closed and the rat immediately receives a 0.8 mA shock (Coulboum Shock Generator) for 2 seconds. The animal is removed immediately after the shock and is replaced in its home cage. 

48 hours later the animal is placed again in the lighted compartment with the door closed for the second trial (T2). The door is opened after 30 seconds and 

Amnesia-inducing drugs cause a significant decrease in the step-through latency at T2. 

15 rats are studied per group. The test is performed blind. 

---

The tests generally involve some form of maze but the simplest is the passive avoidance test. In this the animal learns that in a certain environment it will be punished with an electric shock for some particular action, like stepping onto a special part of the floor of the test chamber. The test of memory is how long the rat avoids (remains passive to) making the movement that will initiate the shock. Of course, drugs that reduce the animal s anxiety also modify the response. Using a maze in its simplest T shape, the animal is placed at the base of the vertical arm and a food reward at the end of one of the horizontal arms. Clearly the animal has to learn which arm contains the reward. Memory is assessed by the time taken for a food-deprived animal to reach the reward and the number of false arm entries. This simple system can be made more complex by introducing many more arms and branches but the principle is the same. 

Administration of scopolamine to rats induces amnesia in passive avoidance learning. EGb administered intraperitoneally 30 mm before the initial trial at doses of 150-500 mg/kg significantly attenuated the amnesic effects of scopolamine on step-through latencies in a retention trial 4 hours after training for the passive avoidance test in rats [107]. Hoyer et d. showed that, using an animal model of in tracer ebroventricular streptozotocin treatment, EGb treatment compensated for deterioration in working memory, reference memory and passive... 

Effects of thioperamide and clobenpropit on the scopolamine-induced learning deficit in the step-through passive avoidance test in mice. 

Figure 1 Effect of clobenpropit on scopolamine-induced shortening of the step-throughlatencyin the passive avoidance test. Male ICRmice (Clea Japan, Inc., Tokyo, Japan), aged 6 weeks and weighing 30-35 g were housed under standard conditions...

CNS neurodegenerative disorders often accompany the impairment of memory and other cognitive functions. This impairment is probably due to selective neuronal death in the cerebral cortex and hippocampus, brain regions that are crucially involved in learning and memory. It has recently been found that the alcohol extract of pistils of C. sativus L. (CSE) affects learning and memory in mice. Oral administration of CSE (125 to 500 mg/kg) alone had no effect on learning behavior of mice in passive avoidance tests, but significantly improved ethanol-induced impairment of memory acquisition. 

Galeotti N, Ghelardini C, Bartolini A. Role of 5-HT4 receptors in the mouse passive avoidance test. J Pharmacol Exp Ther 1998 286 1115-1121. 

After injection of 1.85 g sample to the cerebral ventricle on each of three consecutive days, passive avoidance testing on days 1 and 2 and Y-maze testing on days 3 and 4 were conducted. Learning and memory-retention ability of the mice were performed according to the method of Song (1), while spontaneous alternation behavior of mice in a Y-maze test was performed according to the method of Yamada (2). 

Stimulus-response learning in passive avoidance test —... 

Tropisetron [ICS-205,930, Novoban, (172) in Fig. 14.18 Novartis] is a potent 5-HT, receptor antagonist = 0.38-3.1 nM) (483-485)that has recently been found to possess a, nAChR subtype antagonist activity (437) (see Table 14.13) and a, nAChR partial agonist activity (445). In rat behavioral studies, tropisetron attenuated scopolamine-induced memory deficits in the passive-avoidance test (438), and spatial navigation deficits in the Morris water-maze task (463), and improved the retention of a conditioned response in rats with p-chloroamphetamine-induced deficits (486). Tropisetron is currently marketed for the treatment of nausea and vomiting associated with chemotherapy treatments (485). 

Dimitrova DS, Getova-Spassova DP (2006) Effects of galantamine and donepezil on active and passive avoidance tests in rats induced with hypoxia. J Pharmacol Sci 101 199-204. 

It has been shown that administration of theanine has a significant effect on the release or reduction of neurotransmitters like dopamine and serotonin. It is also known that these neurotransmitters are closely related to memory and learning ability. Theanine does not change activity level or exploration behavior in normal animals. However, it does improve performance on a number of tests of memory and learning, including the active avoidance test and passive avoidance test. ... 

Zarrindast M-R, Kangarlu-Haghighi K, Khalilzadeh A, Fazli-Tabaei S (2006) Influence of intracerebroventricular administration of cannabinergic drugs on morphine state-dependent memory in the step-down passive avoidance test Behav Pharmacol 17 231... 

Van der Poel AM (1967) Ethological study of the behavior of the albino rat in a passive-avoidance test. Acta Physiol Pharmacol Neerl 14 503-505... 

The effect of nutmeg hexane extract on memory and learning has also been studied in mice (5-20mg/kg, oral administration) whereby a significant enhancement has been observed in the elevated plus-maze and passive-avoidance tests. This effect probably involves the deactivation of brain acetylcholinesterase as compared to the untreated control group. 

---