Differential effects of forward or simultaneous conditioned stimulus-unconditioned stimulus intervals on the defensive behavior system of the Norway rat (Rattus norvegicus).

2003 ◽  
Vol 29 (4) ◽  
pp. 334-340 ◽  
Author(s):  
Francisco J. Esmorís-Arranz ◽  
José L. Pardo-Vázquez ◽  
Gustavo A. Vázquez-García
Author(s):  
Sadahiko Nakajima

Wheel running establishes conditioned aversion in rats to a taste solution consumed shortly prior to the running. Many studies have shown that this is a case of Pavlovian conditioning, in which the taste and running respectively act as the conditioned stimulus (CS) and the unconditioned stimulus (US), but extinction of this running-based taste aversion has not been explicitly demonstrated. Experiment 1, using a within-subjects design, showed that saccharin aversion formerly established by a single pairing of an exposure to saccharin solution with a running opportunity was extinguished by two daily exposures to the saccharin solution. However, there was no spontaneous recovery from extinction in the tests which were administered 6 and 27 days after the extinction days. Experiment 2, using a between-groups design, successfully demonstrated extinction and spontaneous recovery of running-ba


1986 ◽  
Vol 96 (3) ◽  
pp. 467-473 ◽  
Author(s):  
A. P. Buckle

SUMMARYThe anticoagulant rodenticide flocoumafen was tested against warfarin-resistant Norway rats (Rattus norvegicus Berk.) infesting farm buildings. Complete control was obtained in 10–21 days (mean 14·2 days) in six treatments in which baits poisoned with 0·005% flocoumafen were maintained, in surplus, until rats ceased to feed from them. A further six treatments, in which the application of poisoned bait was restricted to periodic placements of 50 g, were also completely successful in 15–30 days (mean 21·0 days). Less poisoned bait was used in the restricted flocoumafen treatments than in the unrestricted treatments but the time taken to control the rat infestations was significantly longer.


2018 ◽  
Author(s):  
Tobias Heycke ◽  
Christoph Stahl

Evaluative Conditioning (EC) changes the preference towards a formerly neutral stimulus (Conditioned Stimulus; CS), by pairing it with a valent stimulus (Unconditioned Stimulus; US), in the direction of the valence of the US. When the CS is presented subliminally (i.e., too briefly to be consciously perceived), contingency awareness between CS and US can be ruled out. Hence, EC effects with subliminal CSs would support theories claiming that contingency awareness is not necessary for EC effects to occur. Recent studies reported the absence of EC with briefly presented CSs when both CS and US were presented in the visual modality, even though the CSs were identified at above-chance levels. Challenging this finding, Heycke and colleagues (2017) found some evidence for an EC effect with briefly presented visual stimuli in a cross-modal paradigm with auditory USs, but that study did not assess CS visibility. The present study attempted to replicate this EC effect with different stimuli and a CS visibility check. Overall EC for briefly presented stimuli was absent, and results from the visibility check show that an EC effect with briefly presented CSs was only found, when the CSs were identified at above-chance levels.


Chromosoma ◽  
1984 ◽  
Vol 89 (5) ◽  
pp. 381-386 ◽  
Author(s):  
A. M. Joseph ◽  
Ann C. Chandley
Keyword(s):  

1976 ◽  
Vol 28 (3) ◽  
pp. 231-239 ◽  
Author(s):  
J. H. Greaves ◽  
P. B. Ayres

SUMMARYThe inheritance of resistance to the rodenticide, warfarin, in the Norway rat, Rattus norvegicus, derived from a wild rat population in Scotland was studied in the backcross, intercross and testcross. The resistance was found to be due to a major gene with about the same map position in Linkage Group I as the warfarin-resistance gene, Rw2, which occurs in the wild rat population in Wales. In heterozygotes, the Scottish resistance gene, unlike the Welsh gene, is incompletely penetrant in expression, though the penetrance was found to increase markedly in response to selection. Differences between the Scottish and Welsh types of resistance suggest that the two resistance genes are allelic.


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