Striatum expresses region-specific plasticity consistent with distinct memory abilities.

Area of Science:

• Neuroscience
• Synaptic Plasticity
• Motor Learning

Background:

• The striatum is crucial for learning, with distinct roles for dorsomedial (DMS) and dorsolateral (DLS) regions in goal-directed behavior and habit formation, respectively.
• The underlying synaptic mechanisms, particularly in DMS, remain poorly understood despite extensive research on DLS plasticity.

Purpose of the Study:

• To investigate the synaptic plasticity differences between DMS and DLS during motor skill learning.
• To elucidate the role of spike-timing-dependent plasticity (STDP) in mediating distinct learning modalities within the striatum.

Main Methods:

• Investigated spike-timing-dependent plasticity (STDP) in DMS and DLS using electrophysiological recordings.
• Examined neuronal activity during motor-skill learning in vivo.
• Employed mathematical modeling to analyze the impact of different STDP rules on memory processes.

Main Results:

• Identified symmetric anti-Hebbian STDP in DMS and asymmetric anti-Hebbian STDP in DLS, with opposing plasticity dominance shifts under increased corticostriatal activity.
• Observed transient plasticity engagement in DMS and striatonigral DLS neurons during early motor learning stages.
• Found late-phase mobilization of striatopallidal DLS neurons during motor skill acquisition.

Conclusions:

• Symmetric anti-Hebbian STDP in DMS promotes memory flexibility, essential for adapting goal-directed behaviors.
• Asymmetric anti-Hebbian STDP in DLS favors memory maintenance, supporting the consolidation of habits.
• These findings provide critical insights into the synaptic basis of distinct learning and memory processes mediated by the striatum.