Passive avoidance response test

Improvements in learning and memory tasks with SCH211803 have been demonstrated in rats using the Morris Water Maze and the young rat passive avoidance response test. SCH211803 also improves performance in an operant model of cognition in squirrel monkeys.56... 

Mice treated with phenobarbital (40 mg/kg) on the last 6-7 days before birth showed decreased passive avoidance latencies in the test session at the age of 90 days (ref. 138). Delta-9-THC treatment during pregnancy caused a decreased rate of learning a passive avoidance response on postnatal day 21. However, on day 90 no difference in passive avoidance learning was found (ref. 156). 

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. 

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). 

The STAR-H2 reactor has a central safety rod and an active scram circuit. It also will have a decay heat removal path through the flibe loop. However, in order to achieve the levels of safety required for deployments of tens of thousands of STAR-H2 plants worldwide - sited near cities, it will be essential to avoid core damage even in the absence of a scram. The technology to achieve passive safety response to anticipated transients without scram (ATWS) events was well developed for the IFR concept [XXIV-15] and was famously demonstrated in tests conducted at the EBR-II reactor [XXIV-16]. 

A series of behaviors suggesting deficient response inhibition is also seen following developmental Pb exposure. Specific behavioral deficits are seen on tests of passive avoidance, one way active avoidance, differentied reinforcement of low rates of responding (DHL-EO)" and fixed interval schedules of operant controlled behavior operant extinction and operant response inhibition, spontaneous cdternation," "" and various discrimination reversal problems " "" have also been observed following developmental Pb exposure. 

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