SST neurons in the periaqueductal gray regulate urination and bladder function

Area of Science:

• Neuroscience
• Urology
• Physiology

Background:

• Urination is a complex physiological process controlled by central neural circuits.
• The periaqueductal gray (PAG) is a known control center for urination, but specific neuron types involved are not well-defined.

Purpose of the Study:

• To identify specific neuronal subtypes within the lateral and ventrolateral PAG (l/vlPAG) that regulate the process of urination.
• To elucidate the neural pathways involved in micturition control originating from the l/vlPAG.

Main Methods:

• Identification of somatostatin (SST)-expressing neurons in the l/vlPAG.
• Recording neuronal activity in freely moving animals during urination.
• Optogenetic activation and inhibition of SST-expressing neurons.
• Investigating projections to the pontine micturition center (PMC) and effects after pelvic nerve transection.

Main Results:

• SST-expressing neurons in the l/vlPAG showed activity correlated with urination onset.
• Optogenetic activation of these neurons induced urination and bladder contraction.
• Inhibition of these neurons suppressed ongoing urination.
• Activation of l/vlPAG SST+ neurons projecting to the PMC triggered urination, an effect dependent on the pelvic nerve.

Conclusions:

• l/vlPAG SST-expressing neurons are critical regulators of urination.
• These neurons control micturition via the PAG-PMC pathway.
• This study offers new insights into bladder control mechanisms and potential therapeutic targets for urinary dysfunction.