Whole-Brain Connectome Identifies PMv^LepRb Neurons as a Hypothalamic Hub Linking Metabolic State to Instinctive...

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Neuroendocrinology

Background:

• Metabolic state significantly influences social and reproductive behaviors.
• Neural circuits linking energy signals to behavior are not fully understood.
• The ventral premammillary nucleus (PMv) and its leptin receptor-expressing (LepRb) neurons are implicated in this process.

Purpose of the Study:

• To comprehensively map the brain-wide input-output organization of PMv^LepRb neurons at single-cell resolution.
• To elucidate how these neurons integrate metabolic and motivational information.
• To understand how energy state influences social and reproductive behaviors.

Main Methods:

• Utilized Cre-dependent retrograde (RV) and anterograde (HSV) viral tracing techniques in LepRb-Cre mice.
• Performed 3D reconstruction for detailed circuit mapping.
• Conducted quantitative analysis of projection patterns.

Main Results:

• PMv^LepRb neurons receive convergent inputs from hypothalamic and forebrain regions involved in energy balance, motivation, and limbic processing.
• Outputs project to both input regions and prominently to midbrain/pontine autonomic centers (PAG, PB).
• Forebrain connections are often reciprocal, while brainstem connections are predominantly outgoing.

Conclusions:

• PMv^LepRb neurons integrate metabolic and motivational signals.
• They relay this integrated information to downstream autonomic and behavioral control systems.
• This provides a structural framework for understanding how energy status impacts social and reproductive decision-making.