Rats move nesting materials to create different functional areas: Short report.

Here we document how rats separate their living space into different functional regions. Five groups of four female Sprague Dawley rats were housed in caging systems that consisted of two standard cages connected by a tube. Both cages were provided with the same amount of bedding and nesting materials, but only one contained food and water.

Effects of personality on assessments of anxiety and cognition.

Individual variation in responses to commonly used tests of anxiety and spatial memory is often reported. While this variation is frequently considered to be 'noise', evidence suggests that it is, at least partially, related to consistent individual differences in behavioral responses (i.e.

Voluntary Oral Ingestion of a Sedative Prior to Euthanasia with CO: Behavioural Responses of Mice.

Laboratory mice are commonly euthanised with carbon dioxide (CO); however, there is ample evidence that this gas is aversive. Previous work suggests that sedation achieved via injection with benzodiazepines prior to CO administration could reduce aversive behaviours during euthanasia. We explored the potential of using a voluntarily ingested sedative (tiletamine-zolazepam, Zoletil) prior to euthanasia.

Attitudes of laboratory animal professionals and researchers towards carbon dioxide euthanasia for rodents and perceived barriers to change.

Evidence indicates that carbon dioxide (CO) induces negative affective states (including anxiety, fear and distress) in laboratory rodents, but many countries still accept it for euthanasia. Alternative methods (e.g.

Individual differences in rat sensitivity to CO2.

Feelings of fear, anxiety, dyspnea and panic when inhaling carbon dioxide (CO2) are variable among humans, in part due to differences in CO2 sensitivity. Rat aversion to CO2 consistently varies between individuals; this variation in aversion may reflect CO2 sensitivity, but other personality traits could also account for individual differences in aversion. The aims of this study were to 1) assess the stability of individual differences in rat aversion to CO2, 2) determine if individual differences in sweet reward motivation are associated with variation in aversion to CO2, and 3) assess whether variation in aversion to CO2 is related to individual differences in motivation to approach gains (promotion focus) or maintain safety (prevention focus).

Understanding rat emotional responses to CO.

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO) exposure. The studies reviewed show that CO exposure is aversive to rats, and that rats respond to CO exposure with active and passive defense behaviors. Plasma corticosterone and bradycardia increased in rats exposed to CO.

Variation in the onset of CO-induced anxiety in female Sprague Dawley rats.

Carbon dioxide (CO) is commonly used to kill laboratory rats. Rats find CO aversive and aversion varies between individuals, indicating that rats vary in CO sensitivity. Healthy humans experience feelings of anxiety at concentrations similar to those avoided by rats, and these feelings are diminished by the administration of benzodiazepines.

Evidence for consistent individual differences in rat sensitivity to carbon dioxide.

Carbon dioxide (CO2) gradual-fill is commonly used to kill laboratory rats, but this use remains controversial due to a lack of agreement between studies. Inconsistencies may arise from differences in behaviors measured (e.g.