The lateral preoptic area and ventral pallidum embolden behavior

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Neuropharmacology

Background:

• Previous studies indicated that stimulating the lateral preoptic area (LPO) and ventral pallidum (VP) affects locomotion.
• Incidental observations suggested these areas also influence motivational drive and threat tolerance.

Purpose of the Study:

• To investigate the effects of LPO and VP stimulation on motivational drive and threat tolerance in rats.
• To differentiate the mechanisms underlying boldness induced by LPO versus VP stimulation, particularly the role of dopamine.

Main Methods:

• Infusions of bicuculline (bic) or vehicle into the LPO and VP of rats.
• Behavioral testing included conditioned place preference (CPP), elevated plus maze (EPM), and open field tests assessing threat tolerance (occupancy of lit center for rewards).
• Pharmacological manipulations using dopamine D1 and D2 receptor antagonists, administered systemically or into the nucleus accumbens or VP.

Main Results:

• LPO-bic infusions increased locomotion, field center occupancy, EPM open arm exploration, and CPP, effects attenuated by dopamine antagonists.
• VP-bic infusions increased field center occupancy and CPP without increasing locomotion, with some effects attenuated by dopamine antagonists.
• VP-bic infusions led to compulsive pellet ingestion, even in a lit area, unlike controls.

Conclusions:

• Boldness induced by LPO stimulation is linked to locomotor activity and strongly dopamine-dependent.
• Boldness induced by VP stimulation is independent of locomotor activity and partially dopamine-dependent.
• The emboldening effects from LPO and VP stimulation appear to be fixed action responses rather than goal-directed behaviors.