Enhanced Risky Choice in Male Rats Elicited by the Acute Pharmacological Stressor Yohimbine Involves Prefrontal...

Area of Science:

• Neuroscience
• Behavioral Pharmacology
• Decision-Making Research

Background:

• Acute stress significantly influences risk-based decision-making processes.
• Neural and neurochemical mechanisms underlying stress-induced decision-making alterations remain incompletely understood.
• Glucocorticoids (e.g., cortisol, corticosterone) and yohimbine are pharmacological agents that can mimic aspects of acute stress.

Purpose of the Study:

• To investigate the effects of systemic corticosterone and yohimbine administration on risk-based decision-making in male rats.
• To determine if dopamine D1 receptor stimulation in the dorsal prelimbic cortex (PL) mediates the effects of pharmacological stressors on decision-making.

Main Methods:

• Male rats were subjected to a risk discounting task, involving choices between a certain small reward and a larger, variable reward.
• Systemic administration of corticosterone and yohimbine was employed to model acute stress.
• The role of dopamine D1 receptors in the PL was assessed by concurrent blockade during yohimbine administration.

Main Results:

• Systemic yohimbine administration significantly increased preference for the risky/large reward option.
• Single systemic administration of corticosterone did not notably alter risky choice behavior.
• Co-administration of corticosterone with yohimbine did not potentiate the effects on risky choice; blockade of PL dopamine D1 receptors attenuated yohimbine's effect on risky choice.

Conclusions:

• The findings suggest that dopamine D1 receptor stimulation within the PL is a key neurochemical pathway through which yohimbine promotes risky decision-making.
• This mechanism may also be relevant for understanding how non-pharmacological stressors influence risky choice behavior in rodents.