Study reveals mouse superior colliculus promotes competing actions independent of sensory input
Researchers found that the superior colliculus (SC) in mice promotes competing motor actions independently of sensory stimuli, contrary to previous assumptions about its role. The study used behavioral experiments with audiovisual stimuli and neural inactivation to show that sensory and action-related signals are processed by separate neuron populations in different SC layers. This finding reshapes understanding of how the brain selects between competing actions during decision-making.
A new preprint study challenges the conventional view that the superior colliculus primarily integrates sensory information to guide action selection. Researchers trained mice to locate audiovisual stimuli and recorded neural activity while selectively inactivating different SC regions. They discovered that auditory, visual, and action-related signals are largely segregated across different SC layers and neuron populations. Unilateral SC inactivation reduced contralateral actions without affecting sensory sensitivity, while bilateral inactivation restored left-right behavioral balance. Using a computational model, the team proposed that the prefrontal cortex integrates sensory signals from sensory cortices, while the SC contributes stimulus-independent signals that promote both competing action options. This reframing suggests the SC's primary role in decision-making is facilitating action competition rather than sensory integration.
Limitations & open questions
The study's limitations regarding generalizability to other species, the specific mechanisms by which SC neurons promote competing actions, and whether findings apply to more complex naturalistic decision-making scenarios beyond the trained audiovisual task are not detailed in the abstract.
What different sources said
- bioRxivCenter
The mouse superior colliculus promotes competing actions independently of sensory inputs
Related
Study reveals IDH1 enzyme's role in cardiac metabolic adaptation during cancer-related stress
Researchers discovered that isocitrate dehydrogenase 1 (IDH1) helps the heart adapt to metabolic stress caused by cancer-related mutations through a previously unknown reductive metabolic pathway. The study used stable isotope tracing and genetic knockout models in rat and mouse heart tissue to show that when mitochondrial metabolism is impaired, IDH1 redirects carbon flux toward glutamine-derived citrate formation. This finding expands understanding of how cardiac metabolism responds to oncometabolic stress and may have implications for managing cardiovascular complications in cancer patients.
AI Framework Reveals How β-Arrestin 1 Protein Changes Shape During Activation
Researchers used a transformer-based artificial intelligence model to analyze how the β-arrestin 1 protein's tail region reorganizes when activated by cell surface receptors. The study examined molecular dynamics simulations comparing the protein in resting and active states, uncovering previously unknown conformational changes. This work could improve understanding of how cells regulate signaling pathways involved in numerous physiological and disease processes.
Study Links Pancreatic Cancer Tissue Stiffness to Tumor Progression and Patient Survival
Researchers combined imaging scans and laboratory tissue analysis to show that pancreatic cancer tumors with greater stiffness—driven by dense collagen buildup—correlate with worse patient survival outcomes. The study of nine patients found that magnetic resonance elastography, a non-invasive imaging technique, can detect mechanical properties that reflect underlying tumor biology. These findings suggest that measuring tissue stiffness through imaging could help doctors better characterize pancreatic cancer and guide treatment decisions.