Although animals often learn and monitor the spatial properties of relevant moving objects such as conspecifics and predators to properly organize their own spatial behavior, the underlying brain substrate has received little attention and hence remains elusive. Because the anterior cingulate cortex (ACC) participates in conflict monitoring and effort-based decision making, and ACC neurons respond to objects in the environment, it may also play a role in the monitoring of moving cues and exerting the appropriate spatial response. We used a robot avoidance task in which a rat had to maintain at least a 25cm distance from a small programmable robot to avoid a foot shock. In successive sessions, we trained ten Long Evans male rats to avoid a fast-moving robot (4cm/s), a stationary robot, and a slow-moving robot (1cm/s). In each condition, the ACC was transiently inactivated by bilateral injections of muscimol in the penultimate session and a control saline injection was given in the last session. Compared to the corresponding saline session, ACC-inactivated rats received more shocks when tested in the fast-moving condition, but not in the stationary or slow robot conditions. Furthermore, ACC-inactivated rats less frequently responded to an approaching robot with appropriate escape responses although their response to shock stimuli remained preserved. Since we observed no effect on slow or stationary robot avoidance, we conclude that the ACC may exert cognitive efforts for monitoring dynamic updating of the position of an object, a role complementary to the dorsal hippocampus.

• MeSH
• GABA-A Receptor Agonists pharmacology   MeSH
• Gyrus Cinguli drug effects   physiology   MeSH
• Rats MeSH
• Muscimol pharmacology   MeSH
• Neurons drug effects   physiology   MeSH
• Cues MeSH
• Rats, Long-Evans MeSH
• Attention drug effects   physiology   MeSH
• Spatial Behavior drug effects   physiology   MeSH
• Reaction Time physiology   MeSH
• Avoidance Learning drug effects   physiology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Animals can organize their behavior with respect to other moving animals or objects; when hunting or escaping a predator, when migrating in groups or during various social interactions. In rats, we aimed to characterize spatial behaviors relative to moving objects and to explore the cognitive mechanisms controlling these behaviors. Three groups of animals were trained to avoid a mild foot-shock delivered in one of three positions: either in front, on the left side, or on the right side of a moving robot. We showed the rats can recognize and avoid these specific areas. The avoidance behavior specific for the left or right side of the robot demonstrated animals not only react to "simple" stimuli such as increasing noise level or growing retinal image of an approaching object, but they process their spatial position relative to the object. Using an all-white robot without prominent visual patterns that would distinguish its different sides, we showed that the behavior does not depend on responses to prominent visual patterns, but that the rats can guide their navigation according to geometrical spatial relationship relative to the moving object. Rats' competence for navigation in space defined by a moving object resembles navigation abilities in stationary space. Recording of hippocampal single unit activity during rat's interaction with the robot proved feasibility of the task to uncover neuronal mechanism of this type of navigation.

• Publication type
• Journal Article MeSH

The hippocampus (HPC) is essential for navigation and memory, tracking environmental continuity and change, including navigation relative to moving targets. CA1 ensembles expressing immediate-early gene (IEG) Arc and Homer1a RNA are contextually specific. While IEG expression correlates with HPC-dependent task demands, the effects of behavioral demands on IEG-expressing ensembles remain unclear. In three experiments, we investigated the effects of context switch, sustained presence, and task demands on dorso-proximal CA1 IEG+ ensembles in rats. Experiment 1 showed that the size of IEG+ (Arc, Homer1a RNA) ensembles dropped to baseline during uninterrupted 30-min exploration, reflecting familiarization, unless a context switch was present. Context-specificity of the ensembles depended on both environment identity and timing of the context switch. Experiment 2 found no effect of HPC-dependent mobile robot avoidance or HPC-independent avoidance of a stationary robot on IEG+ ensembles beyond mere exploration. Experiment 3 replicated these findings for c-Fos protein. The data suggest that IEG+ ensembles are driven by a context switch and shrink over time during sustained presence in the same environment. We found no evidence of task demands or their change affecting the size, stability over time, or task-specificity of IEG+ ensembles. These results shed light on the temporal dynamics of CA1 IEG+ ensembles, and their control by contextual and behavioral factors.

• MeSH
• Behavior, Animal physiology   MeSH
• Cytoskeletal Proteins genetics   metabolism   MeSH
• CA1 Region, Hippocampal * metabolism   physiology   MeSH
• Homer Scaffolding Proteins * metabolism   genetics   MeSH
• Rats MeSH
• Genes, Immediate-Early * physiology   MeSH
• Rats, Long-Evans * MeSH
• Nerve Tissue Proteins genetics   metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH