Aggressive behavior and stress response after oxytocin administration in male Norway rats selected for different attitudes to humans

Oxytocin (OXT) is known to influence on social behaviors, including intermale aggression and hypothalamic-pituitary-adrenal (HPA) axis activity. However, there are no data on the effects of oxytocin on intermale aggression and HPA axis activity in rats selected for elimination and enhancement of aggressiveness towards humans. The aim of this study is to elucidate the role […]

Assessment of spontaneously occurring periodic limb movements in sleep in the rat

OBJECTIVE: Periodic limb movements in sleep (PLMS) are often associated with the restless legs syndrome (RLS). Although the dopaminergic system seems to be involved, the pathophysiology of PLMS and RLS is still obscure. The objective of this study is to explore whether a PLMS-like phenomenon can be observed in rodents in order to elucidate the […]

Sleep–wake study in an animal model of acute and chronic heat stress

The study of the variations in different parameters of sleep–wake states following exposure to high environmental heat in three different age groups of freely moving rats have been presented in this paper. Each age group of rats was subdivided in three group (i) acute heat stress — subjected to a single exposure for 4 h […]

What is it like to be a rat? Rat sensory perception and its implications for experimental design and rat welfare

This review of rat sensory perception spans eight decades of work conducted across diverse research fields. It covers rat vision, audition, olfaction, gustation, and somatosensation, and describes how rat perception differs from and coincides with ours. As Nagel’s seminal work (1974) implies, we cannot truly know what it is like to be a rat, but […]

Tests for emotionality in rats and mice: A review

This paper examines the concept of emotionality, particularly in relation to measures taken in ‘novel environment’ tests (e.g. the open field). Evidence of several different types is reviewed to assess the validity of the measures in relation to common assumptions underlying their use. In response to increased light and noise, open field defecation increases and […]

Enriched sensory experience in adulthood increases subsequent exploratory behaviour in the rat

Hooded rats were reared under identical conditions until 3 months old. They were then exposed for 5 weeks to either a sensorily enriched or an impoverished environment. Each subject was then observed for 15 min in a novel Y-maze. Animals exposed to the enriched environment showed the strongest exploration tendency, particularly early in the trial. […]

Performance on the hebb-williams maze as related to discrimination and reversal learning in rats

Performance on the Hebb-Williams Maze was studied in relation to visual form discrimination and reversal. Three groups, each of twenty hooded rats, were first tested on the Hebb-Williams Maze and then on discrimination and reversal in a T-maze with either vertical and horizontal black and white stripes or a black circle and triangle against white […]

Prudent sperm allocation in Norway rats, Rattus norvegicus: a mammalian model of adaptive ejaculate adjustment

In species where there is postcopulatory competition between males in the form of sperm competition, theory predicts that males should show prudent sperm allocation. Specifically, males should adjust the number of sperm that they inseminate in response to variations in the risk and intensity of sperm competition. Some experimental evidence for nonmammalian species indicates that […]

Using the cross point of demand functions to assess animal priorities

We developed a method to assess the substitutability of two reinforcers by using the divergence of the cross point of two demand functions. Two kinds of water were used as reinforcers, namely distilled water and quinine water. We tested 16 rats, Rattus norvegicus, from two strains in a closed economy. A single demand function for […]