Switchmaze: automated, ongoing measurement of motivation and drive switching in mice

Switching between brain states underlying motivated behaviours is fundamental to survival in a dynamic environment. Inflexible repetitive motivated behaviours are a hallmark of several neuropsychiatric disorders such as anorexia nervosa and obsessive compulsive disorder. However, studies of motivated behaviours, such as feeding, drinking and socializing, seldom focus on switching between them or the underlying neural mechanisms, termed drives. In this study, we establish a behavioural assay of motivational switching in mice, using a new automated behavioural monitoring device, the Switchmaze. Motivation switching is measured as the ratio of single probe entries to continuous exploitation runs. Transition analysis is used to further dissect altered motivation switching. To study the neural underpinnings of motivation switching, we present a proof-of-concept experiment using chemogenetic inhibition of the prefrontal-hypothalamic axis. This increased the rate of motivation switching, highlighting the involvement of this pathway in drive switching.