Sex-dependent noradrenergic modulation of premotor cortex during decision-making

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Behavioral Neuroscience

Background:

• The rodent premotor cortex (M2) integrates sensory and cognitive information for action planning.
• Norepinephrine (NE) from the locus coeruleus (LC) modulates neural signal-to-noise ratios in cortical areas, enhancing stimulus salience.

Purpose of the Study:

• To investigate the necessity of β-noradrenergic signaling for action planning in the anterior M2 during decision-making.
• To explore the role of β-noradrenergic signaling in suppressing irrelevant information and its impact on behavior and neural activity.

Main Methods:

• Rats performed a two-alternative forced choice task.
• A β-noradrenergic antagonist (propranolol) was administered.
• Behavioral outcomes and neural decoding were analyzed.
• Differential gene expression of β2 noradrenergic receptor RNA was examined across sexes.

Main Results:

• Loss of β-noradrenergic signaling impaired action plan signals in anterior M2.
• This disruption led to a failure in suppressing irrelevant action plans, hindering cue information decoding.
• Decision times were delayed, trial omissions increased, particularly in female rats.
• Differential expression of β2 noradrenergic receptor RNA was observed between sexes, especially in inhibitory neurons.

Conclusions:

• β-noradrenergic signaling is essential for effective action planning in the anterior M2 during decision-making.
• This signaling mechanism suppresses irrelevant information, facilitating efficient action selection.
• Sex differences in behavioral and neural responses suggest a role for differential receptor expression.