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Morvan, T.

Publications and source records attributed to Morvan, T..

2 recordsLinked to original sources

The Towers Foraging Park: A Flexible Naturalistic Framework to Study Learning, Decision-Making, and Motor Control in Freely Moving Mice

Adaptive behavior depends on a variety of brain functions, such as learning, decision-making, spatial navigation and motor control, which have been studied using two main strategies. Trial-based tasks allow their mechanistic dissection but tend to generate highly stereotypical behavior, whereas open-field investigations capture naturalistic dynamics with less experimental control. To leverage the strengths of both approaches, we developed a behavioral framework which recreates dilemmas faced by animals during patch foraging. In the Tower Foraging Park (TFP), mice harvest rewards along square towers (patches) by making quarter-turns around them in a single direction (exploit) and alternating between towers (explore) as patches eventually deplete. Within a couple of sessions, naive mice performed quarter-turns in the rewarded direction with increasing vigor and reduced variability, and switched towers after short exploitation bouts. When the harvest direction was reversed, mice rapidly adapted their turning direction, with quarter-turn trajectory variability and speed becoming decoupled. Mice subjected to daily reversals adapted progressively faster, revealing meta-learning. When the next rewarding tower became harder to locate, all trained mice increased exploitation duration, although metalearners outperformed animals trained under stable contingencies. Altogether, the TFP produced behavior consistent with foraging theory and revealed new processes facilitating flexible foraging: meta-learning and the decoupling of movement variability and speed. Moreover, because the TFP accommodates diverse protocol variants, adheres to FAIR principles, and is fully compatible with modern neurophysiological techniques, it provides a promising platform for mechanistic investigations of brain functions underlying adaptive behavior while maintaining ethological validity.

animal behavior and cognition↗

Running, Fast and Slow: The Dorsal Striatum Sets the Cost of Movement During Foraging

Humans and other animals adjust when and how fast they execute goal-directed actions according to expected costs and benefits. Yet, the behavioral principles and brain regions underlying adaptive vigor control remain poorly understood. Here, we developed a self-paced foraging task in which rats must run across a motorized treadmill to collect rewards, allowing separate manipulation of benefit (reward delivery probability) and cost (effort). Throughout the foraging sessions, run timing and speed jointly reflected the rats idiosyncratic urgency to obtain rewards. In contrast, when the cost of crossing the treadmill increased, rats ran faster to maintain a high reward rate while run timing remained stable. Consistent with distinct mechanisms for adapting to costs or benefits, dorsal striatum lesions primarily limited running speed under effortful conditions, whereas ventral striatum lesions reduced rewardseeking urgency at session onset. Together, these findings suggest that vigor is modulated by costs and benefits through distinct striatal circuits.

neuroscience↗