Context-Dependent Sensory Processing across Primary and Secondary Somatosensory Cortex.

Area of Science:

• Neuroscience
• Sensory Processing
• Cognitive Neuroscience

Background:

• The brain integrates current sensory input with past experiences for environmental interpretation.
• The distinct roles of primary (S1) and secondary (S2) somatosensory cortices in experience-dependent stimulus processing remain largely unknown.

Purpose of the Study:

• To investigate how S1 and S2 process somatosensory stimuli influenced by recent experiences.
• To elucidate the functional segregation and integration between S1 and S2 in a working memory context.

Main Methods:

• Simultaneous multi-area population imaging of projection neurons in mice.
• Focal optogenetic inactivation to probe neural circuit function.
• A whisker-based working memory task to assess behavioral relevance.

Main Results:

• Neural activity representing current stimuli, recalled stimuli (cued recall), and stimulus category are distributed across S1 and S2.
• S2 plays a critical role in processing cued recall and its transmission to S1.
• S2 exhibits persistent encoding of cued recall and stimulus category, even without active task demands.
• S1 encodes stimulus category information essential for task performance, independent of S2 pathways.

Conclusions:

• Somatosensory cortices S1 and S2 exhibit both distributed and segregated functions in context-dependent sensory processing.
• S2 is vital for memory recall and inter-areal communication, while S1 is critical for task execution based on sensory category.