Regulation of Decision Threshold by the Locus Coeruleus

Area of Science:

• Neuroscience
• Decision-Making Science
• Computational Neuroscience

Background:

• Decision-making under uncertainty requires balancing speed and accuracy.
• Adjusting decision thresholds is a key mechanism for this balance.
• Neural circuits directly controlling decision thresholds remain largely unidentified.

Purpose of the Study:

• To investigate the role of the locus coeruleus norepinephrine (LC-NE) system in regulating decision thresholds.
• To identify the specific neural mechanisms by which LC-NE influences the speed-accuracy trade-off.

Main Methods:

• Cell-type specific chemogenetic manipulations in rodents.
• Systemic administration of the α2 adrenergic receptor (α2 AR) agonist, clonidine.
• Behavioral analysis of decision-making tasks, measuring reaction time and accuracy.

Main Results:

• LC-NE activation significantly increased decision thresholds, enhancing accuracy at the cost of speed.
• Systemic administration of clonidine replicated the increase in decision thresholds caused by LC-NE activation.
• α2 AR activation specifically altered decision thresholds without affecting task engagement.

Conclusions:

• The LC-NE system directly regulates decision thresholds during perceptual decision-making.
• Downstream activation of α2 ARs mediates the effect of LC-NE on decision thresholds.
• This provides a novel neural circuit mechanism for controlling the speed-accuracy trade-off.