Parvalbumin Interneurons Determine Emotional Valence Through Modulating Accumbal Output Pathways

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Molecular Psychiatry

Background:

• Parvalbumin (PV)-expressing GABAergic interneurons are crucial for striatal function.
• The specific roles of PV interneurons in the ventral striatum and their influence on emotional states remain largely unexplored.

Purpose of the Study:

• To investigate if stimulating ventral striatal PV interneurons can modulate emotional valence in mice.
• To elucidate the mechanisms by which PV interneurons influence emotional behaviors via spiny projection neurons (SPNs).

Main Methods:

• Utilized optogenetic stimulation and inhibition techniques in mice during conditioned place preference (CPP) and aversion (CPA) paradigms.
• Measured neuronal activity using Fos expression in direct pathway SPNs (dSPNs) and indirect pathway SPNs (iSPNs).
• Investigated the role of calretinin-expressing (CR) interneurons as a control.

Main Results:

• Activation of ventral striatal PV interneurons during CPP training induced place preference.
• Suppression of these interneurons led to conditioned place aversion.
• PV interneuron activation increased Fos expression in dSPNs and impaired lithium chloride-induced CPA.
• Differential activation/suppression of dSPNs and iSPNs resulted in CPP or CPA, respectively.
• Modulation of CR interneurons did not affect emotional valence.

Conclusions:

• PV interneurons in the ventral striatum bidirectionally control emotional valence.
• This control is mediated through the regulation of accumbal SPN activity.
• Targeting PV interneuron activity presents a potential therapeutic strategy for emotional disorders.