TY - JOUR
T1 - Assessment of impulsivity using an automated, self-adjusting delay discounting procedure
AU - Carr, Madison R.
AU - van Mourik, Yvar
AU - Gómez-Sotres, Paula
AU - Solinas, Marcello
AU - de Vries, Taco J.
AU - Pattij, Tommy
N1 - Publisher Copyright:
© 2024 The Authors
PY - 2024/12/18
Y1 - 2024/12/18
N2 - Modelling delay discounting behavior in rodents is important for understanding the neurobiological mechanisms underlying cognitive control and associated impulsivity disorders. Conventional rodent delay discounting procedures require extensive training and frequent experimenter interaction, as rodents are tested in separate operant chambers away from their home cage. To address these limitations, we adapted and characterize here a self-adjusting delay discounting procedure to an automated CombiCage setup. Rodents were trained during the most active phase of the light-dark cycle, completing 120 trials daily. During each session, we measured large reward preference, mean adjusted delay, and trial participation across multiple delays. Results showed that rodents exhibited discounting behavior after two weeks, with performance stability increasing at 7 weeks training with delay. We also evaluated the influence of altering the consecutive choice criteria (ccc), number of trial choices for a delay step to adjust up or down. Lower ccc (3 vs 8) increased both the number of delay steps encountered per session and task participation. Additionally, we examined the effects of pharmacological interventions, including the psychostimulant amphetamine and the dopamine D1 receptor antagonist, SCH23390. A high dose amphetamine reduced preference for large immediate and short delayed rewards and decreased the mean adjusted delay in a non-dose dependent manner, while SCH23390 did not affect task performance. Together, this novel automated self-adjusting procedure enables high-throughput collection of delay discounting data, with potential applications for investigating impulsivity across the lifespan. However, the current extended session design may limit its suitability for pharmacological evaluations.
AB - Modelling delay discounting behavior in rodents is important for understanding the neurobiological mechanisms underlying cognitive control and associated impulsivity disorders. Conventional rodent delay discounting procedures require extensive training and frequent experimenter interaction, as rodents are tested in separate operant chambers away from their home cage. To address these limitations, we adapted and characterize here a self-adjusting delay discounting procedure to an automated CombiCage setup. Rodents were trained during the most active phase of the light-dark cycle, completing 120 trials daily. During each session, we measured large reward preference, mean adjusted delay, and trial participation across multiple delays. Results showed that rodents exhibited discounting behavior after two weeks, with performance stability increasing at 7 weeks training with delay. We also evaluated the influence of altering the consecutive choice criteria (ccc), number of trial choices for a delay step to adjust up or down. Lower ccc (3 vs 8) increased both the number of delay steps encountered per session and task participation. Additionally, we examined the effects of pharmacological interventions, including the psychostimulant amphetamine and the dopamine D1 receptor antagonist, SCH23390. A high dose amphetamine reduced preference for large immediate and short delayed rewards and decreased the mean adjusted delay in a non-dose dependent manner, while SCH23390 did not affect task performance. Together, this novel automated self-adjusting procedure enables high-throughput collection of delay discounting data, with potential applications for investigating impulsivity across the lifespan. However, the current extended session design may limit its suitability for pharmacological evaluations.
KW - Amphetamine
KW - Animal model
KW - Automated
KW - Delay discounting
KW - Homecage
KW - Impulsivity
KW - Self-adjusting
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U2 - 10.1016/j.bbr.2024.115405
DO - 10.1016/j.bbr.2024.115405
M3 - Article
AN - SCOPUS:85212528238
SN - 0166-4328
VL - 480
SP - 1
EP - 8
JO - Behavioural Brain Research
JF - Behavioural Brain Research
M1 - 115405
ER -