[Imaging brain activity in virtual reality: abnormal hippocampal cognitive maps in autism model mice].

Researchers used virtual reality to study brain activity in mice with autism-like traits. They found that these mice had unusual patterns of brain cell activity in the hippocampus (a brain area important for memory and navigation). While normal mice developed organized brain maps during learning tasks, the autism model mice showed distorted patterns - they didn't respond normally to landmarks but showed excessive responses to rewards. This may help explain some of the different ways people with autism perceive and interact with their environment.

This review examines the use of virtual reality (VR) combined with two-photon calcium imaging to study hippocampal function in autism model mice. The research focused on cognitive mapping in the hippocampus during spatial learning tasks. In typical mice, place cells increased as learning progressed, with higher density at behaviorally relevant locations like rewards and landmarks. However, Shank2-deficient autism model mice showed abnormal hippocampal mapping patterns - they did not increase place cell activity at landmarks but showed excessive activity at reward locations.

These mice also demonstrated increased running behavior and reward-seeking. The findings suggest that autism may involve distorted hippocampal information representation affecting spatial cognition.

These findings suggest that spatial cognition and environmental mapping differences in autism may have neurobiological origins in hippocampal dysfunction. This could inform understanding of navigation difficulties, sensory processing differences, and reward-seeking behaviors in autism, potentially leading to targeted interventions.

This is a review paper without specific sample sizes reported. Findings are based on animal models which may not fully translate to human autism. The research focuses on one specific autism model (Shank2-deficient mice) and may not represent the full spectrum of autism presentations.

The symptoms and behavioral abnormalities of brain diseases are thought to be caused by the dysfunction of neural circuits formed by numerous neurons. Virtual reality (VR) is used for behavioral tasks under head fixation and has the advantage of precise control of experimental conditions. In this review, we first overview the application of VR in rodent neuroscience, introduce our research on two-photon calcium imaging of the hippocampus of autism spectrum disorder (ASD) model mice navigating a VR environment, and then discuss how hippocampal dysfunction can relate to ASD phenotypes. By combining a VR system with two-photon microscopy, we clarified the formation of hippocampal CA1 place cell maps in mice undergoing spatial learning in VR.

As mice learned, the number of place cells increased, and the density of cells that responded to places with behaviorally relevant features such as rewards and landmarks increased more than cells active elsewhere. Furthermore, many stable place cells responded at landmark and reward locations. Shank2-deficient ASD model mice spent more time running and received more rewards. In their hippocampal maps, the proportion of cells active at landmarks did not increase, whereas the proportion of cells active at rewards excessively increased.

Individuals with ASD are known to show unique tendencies in their perception and cognition of the world around them, but the detailed brain mechanisms remain unclear. It is thus possible that some ASD cases involve cognitive mapping abnormalities, such as the distortion of hippocampal information representation that our study revealed.