Free-running spontaneous alternation refers to the animal’s tendency to prefer the least recently visited locations in successive spatial choices, which is attributed to the animals’ choice between stimuli based on prior experience.   Turn alternation , which is observed in directional choices preceded by a forced turn in one direction, also reflects the animals’ tendency to alternate between directional choices but this tendency has been assumed to rely on other cues (e.g., proprioceptive cues) derived from the prior responses (e.g., forced turn in one direction).  Based on previous studies, the turn alternation appears to rely on more primitive (lower-form) information features and to be a more frequently observed empirical phenomenon than the spontaneous alternation.  We investigated these two behavioral alternation tendencies in Artemia sp . Experiment 1 tested the continuous spontaneous alternation (cSAB) performance of Artemia sp. in two different mazes: t-maze (three options) and plus maze (four options).  Experiment 2 tested the turn alternation performance of Artemia sp. counter-balancing the direction of initial forced-turn between subjects.  Our results showed that Artemia sp. had nearly chance level spontaneous alternation performance in the t-maze and plus maze whereas a higher than chance level turn alternation performance.  These results support the ubiquity of turn alternation tendency across species and point at the lack of spontaneous alternation in Artemia sp.

Previous studies showed that humans and mice can maximize their rewards in two alternative temporal discrimination tasks by incorporating exogenous probabilities and endogenous timing uncertainty into their decisions. The current study investigated if the probabilistic relations modulated the temporal discrimination performance in scenarios with more than two temporal options. In order to address this question, we tested humans (Experiment 1) and mice (Experiment 2) in the dual-switch task , which required subjects to discriminate three time intervals (short, medium, and long durations) in a sequential fashion. The latencies of switches from short to medium and from medium to long option were the main units of analysis. The results revealed that the timing of switches between the first two options (short-to-medium) were sensitive to probabilistic information in both humans and mice. However, mice but not humans adapted the timing of their subsequent switches between the last two options (medium-to-long) based on the probabilistic information associated with these latter options. These results point at a suboptimal tendency in the temporal decisions of humans with multiple options.

These guidelines follow the recommendation of a number of external bodies to regulate the use of animals in research. They can be used both for transparency in publication, and in this sense they extend what is being requested by journals, or for regulatory or funding institutions, to request information prior, during, or after funding, and to ensure adherence to regulations.

This checklist focuses on the use of rodents in research. Other species (such as marine mammals, primates, or invertebrates) will be covered in future separated checklists.

This checklist is based on and extends the following guidelines: Animals in Research Ethical Guidelines, Guidance for the Description of Animal Research in Scientific Publications, Animals Welfare Act, and ARRIVE guidelines.

Timing is a ubiquitous process that underlies a great variety of human activities and depends on highly conserved neuronal circuitry, the cortico-striatal loops. The peak interval (PI) task is an operant task that conditions subjects to initiate and terminate behavioral responses bracketing a fixed interval associated with reinforcement. Performance in this task depends on the efficacy of temporal control processes that coordinate interval encoding and decoding, instrumental response innitiation, cessation and maintenance, and motor control. Here, we used the PI procedure to characterize temporal control in zQ175 knockin (KI) and BAC HD transgenic (Tg) mice generated to model Huntington's Disease (HD), and contrast the result with previously published R6/2 Tg PI data. HD is a progressive neurodegenerative disorder that involves degeneration of the same neural circuits underlying temporal information processing and control of motor output. Our results indicate that temporal control is disrupted in R6/2 Tg and zQ175 KI mice but intact in BAC HD Tg mice. Trial-by-trial analysis of break-run patterns in response rates indicated that shifts in zQ175 KI response curves were driven by significant delays in response initiation and cessation. Similar temporal control deficits were previously reported in HD patients and R6/2 transgenic HD mice. These findings support the use of zQ175 mice in preclinical studies of HD-related cognitive deficits. They provide evidence of a strong homology between the human and rodent neural bases of temporal information processing, temporal response control, and their pathology in neurodegeneration.