Dopamine D1-D2 signalling in hippocampus arbitrates approach and avoidance

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Molecular Psychiatry

Background:

• The hippocampus and dopamine circuits are crucial for decision-making in anxiety-provoking situations.
• Understanding dopamine's modulation of hippocampal emotional processing is key to resolving approach-avoidance conflicts.

Purpose of the Study:

• To investigate how dopaminoceptive neurons in the male mouse ventral hippocampus (vHipp), distinguished by dopamine D1 or D2 receptor expression, contribute to decision-making under anxiety.
• To elucidate the distinct roles of D1 and D2 receptor-expressing neurons in processing salient stimuli and mediating behavioral responses.

Main Methods:

• Molecularly characterized dopaminoceptive neurons in the male mouse ventral hippocampus (vHipp) based on dopamine D1 and D2 receptor expression.
• Investigated transcriptional distinctness and topographical organization of these neurons across vHipp subfields.
• Analyzed neuronal recruitment and activity profiles during anxiogenic exploration in the ventral subiculum.

Main Results:

• Dopamine D1 and D2 receptor-expressing neurons in the vHipp are transcriptionally distinct and topographically organized.
• Both neuron types are recruited during anxiogenic exploration in the ventral subiculum, exhibiting distinct investigative and behavioral selection profiles.
• These neuronal populations mediate opposing approach-avoidance behaviors and are differentially modulated by dopaminergic transmission.

Conclusions:

• Ventral hippocampus dopamine dynamics play a critical role in gating exploratory behaviors during contextual uncertainty.
• Dopamine receptor-expressing neurons in the vHipp are integral to the neural computations governing emotional states and adaptive decision-making.