TY - JOUR

T1 - Modelling Affective Pain in Mice: Effects of Inflammatory Hypersensitivity on Place Escape/Avoidance Behaviour, Anxiety and Hedonic State

AU - Refsgaard, Louise Konradsen

AU - Hoffmann-Petersen, Julie

AU - Sahlholt, Maj

AU - Pickering, Darryl S

AU - Andreasen T., Jesper

PY - 2016

Y1 - 2016

N2 - BackgroundThe place escape/avoidance paradigm (PEAP) has been used to assess the affective component of pain in rats. Using the Complete Freund’s Adjuvant (CFA) model of inflammatory pain, the current study aimed at developing a mouse version of PEAP (PEAP) and investigating the relation between PEAP and other behavioural responses, namely anxiety-like behaviour, locomotor activity, and hedonic state.New MethodA novel paradigm assessing the affective component of pain in mice was developed by modifying the setup known from rat studies: Animals were forced to stay 2x5 min in the light and the dark area of a box while being stimulated with a suprathreshold filament on the untreated or treated paw, respectively. This was followed by a 30-min test with unrestricted movement. Anxiety-like behaviour, locomotor activity, and hedonic state were assessed with the elevated zero maze (EZM), an open field setup, and a saccharin preference test, respectively, and correlated with the PEAP behaviour to examine potentially confounding parameters of the novel paradigm.ResultsIn the PEAP, CFA-treated animals spent more time in the light area. CFA also increased anxiety-like behaviour significantly, whereas locomotor activity was unaffected. A significant, albeit modest, reduction in saccharin preference was observed. PEAP responses showed no significant correlations with any other behavioural measure.Comparison with Existing Method and ConclusionsThe PEAP results suggest that this paradigm might be successfully applied in mice to study affective pain. CFA treatment was associated with increased anxiety-like behaviour and anhedonia; however, this appeared unrelated to the PEAP responses.

AB - BackgroundThe place escape/avoidance paradigm (PEAP) has been used to assess the affective component of pain in rats. Using the Complete Freund’s Adjuvant (CFA) model of inflammatory pain, the current study aimed at developing a mouse version of PEAP (PEAP) and investigating the relation between PEAP and other behavioural responses, namely anxiety-like behaviour, locomotor activity, and hedonic state.New MethodA novel paradigm assessing the affective component of pain in mice was developed by modifying the setup known from rat studies: Animals were forced to stay 2x5 min in the light and the dark area of a box while being stimulated with a suprathreshold filament on the untreated or treated paw, respectively. This was followed by a 30-min test with unrestricted movement. Anxiety-like behaviour, locomotor activity, and hedonic state were assessed with the elevated zero maze (EZM), an open field setup, and a saccharin preference test, respectively, and correlated with the PEAP behaviour to examine potentially confounding parameters of the novel paradigm.ResultsIn the PEAP, CFA-treated animals spent more time in the light area. CFA also increased anxiety-like behaviour significantly, whereas locomotor activity was unaffected. A significant, albeit modest, reduction in saccharin preference was observed. PEAP responses showed no significant correlations with any other behavioural measure.Comparison with Existing Method and ConclusionsThe PEAP results suggest that this paradigm might be successfully applied in mice to study affective pain. CFA treatment was associated with increased anxiety-like behaviour and anhedonia; however, this appeared unrelated to the PEAP responses.

U2 - 10.1016/j.jneumeth.2016.01.019

DO - 10.1016/j.jneumeth.2016.01.019

M3 - Journal article

C2 - 26820902

VL - 262

SP - 85

EP - 92

JO - Journal of Neuroscience Methods

JF - Journal of Neuroscience Methods

SN - 0165-0270

ER -