Secondary Somatosensory Cortex Is Required for Learning but Not Execution of a Tactile Discrimination

Area of Science:

• Neuroscience
• Somatosensory System Research
• Learning and Memory

Background:

• The precise roles of the primary (S1) and secondary (S2) somatosensory cortex in tactile processing and learning remain unclear.
• The interplay between S1 and S2 in somatosensory function requires further elucidation.

Purpose of the Study:

• To investigate the role of S2 and its interaction with S1 in the acquisition of a whisker-dependent tactile texture discrimination task.
• To determine the necessity of S2 during different phases of learning and skill execution.

Main Methods:

• Utilized DREADDs (Designer Receptors Exclusively Activated by Designer Drugs) for reversible bilateral inhibition of S1 and/or S2 in mice.
• Assessed the impact of S1/S2 inhibition on the mice's ability to learn a tactile discrimination task involving texture identification of foraging bowls.

Main Results:

• Both S1 and S2 were found to be critical for learning the tactile discrimination.
• S2 function was essential during the learning phase but not for post-training consolidation or execution of the learned task.
• S2's role was specific to tactile learning and not required for olfactory discrimination.

Conclusions:

• S1 and S2 interact during the learning of new tactile discriminations.
• The learned tactile skill eventually becomes independent of S2, highlighting distinct roles in learning versus execution.