1. Crying With Laughter: Adapting the Tickling Protocol to Address Individual Differences Among Rats in Their Response to Playful Handling
- Author
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Birte L. Nielsen, Alistair Lawrence, Sarah Brown, Simone Meddle, Vincent Bombail, Emma Tivey, Tayla J Hammond, Physiologie de la Nutrition et du Comportement Alimentaire (PNCA (UMR 0914)), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Scotland's Rural College (SRUC), Modélisation Systémique Appliquée aux Ruminants (MoSAR), Universities Federation for Animal Welfare (UFAW), and SB, SM, and AL acknowledge the Roslin Institute strategic grant funding from the U.K. Biotechnology and Biological Sciences Research Council (BB/P013759/1). AL also acknowledges the funding support from the Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS). VB acknowledges the funding support from the Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE). ET is supported by the Principal's Career Development Scholarship from the University of Edinburgh.
- Subjects
Dorsum ,Opinion ,social play ,playful handling ,Veterinary medicine ,media_common.quotation_subject ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,playful handlng ,rough-and-tumble play ,Developmental psychology ,Laughter ,03 medical and health sciences ,0302 clinical medicine ,SF600-1100 ,medicine ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Social play ,pinning ,ComputingMilieux_MISCELLANEOUS ,media_common ,[SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior ,General Veterinary ,Crying ,05 social sciences ,Tickling ,Positive interaction ,USV ,Anticipation ,rats ,tickling ,Anxiety ,Veterinary Science ,medicine.symptom ,Psychology ,030217 neurology & neurosurgery - Abstract
It has been over 20 years since the first scientific papers on rat tickling were published (1, 2). Rats were found to emit ultrasonic vocalizations in the 50-kHz range (hereafter referred to as USVs) when a human performed rapid manual stimulation on their dorsoventral region. Such tickling of rats by a human hand is trying to imitate the rough-and-tumble play seen in young rats of both sexes (3, 4). Emission of USVs by the rat indicates that it enjoys being tickled (5–7), as USVs have been linked with positive emotions (8, 9), are emitted in anticipation of, and during, social play (10, 11), and have been suggested to be homologous to human laughter (12). To date, more than 70 scientific articles on rat tickling have been published1, and the consensus is that tickling induces positive emotions in rats. Indeed, in a systematic review, LaFollette et al. (13) found that tickling increased USVs and human hand approach behavior, and decreased measures of anxiety in rats. In this Opinion paper, we consider whether current methods of tickling overemphasize the use of pinning (Figure 1) to which there may be a wider response variation than commonly acknowledged. We do not dispute that tickling can be a positive way to handle juvenile rats, but tickling may not always be perceived as a positive interaction by the rat, and we raise the possibility that tickling methods need to be revised. In particular, we suggest incorporating more aspects of play during tickling (increased diversity) and adapting the method to individual rats' responses (increased flexibility) to achieve positive emotions and increased welfare across a wider cohort of rats. Open in a separate window Figure 1 (A) Pinning is a component of social play in rats, where one rat has its dorsal surface pinned to the ground, while the other rat is in a dominant posture above. (B,C) Pinning has become the main component of the methodology used when tickling rats, as it elicits 50-kHz ultrasonic vocalizations (USVs). Pinning has been used in the past as a means to quantify rough-and-tumble play between rats (14). However, rough-and-tumble play is much more than just pinning, and USVs during pinning are frequent when being tickled by a human (1), but less so when being pinned during play (10, 15). Drawings are by Tayla J. Hammond.
- Published
- 2021
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