Carotid Body Function in Tyrosine Hydroxylase Conditional Olfr78 Knockout Mice

Area of Science:

• Physiology
• Neuroscience
• Molecular Biology

Background:

• The Olfr78 gene encodes a G-protein-coupled receptor found in carotid body (CB) glomus cells.
• Glomus cells are oxygen-sensing cells crucial for regulating breathing during hypoxia.
• Olfr78's role as a lactate receptor mediating the hypoxic ventilatory response (HVR) is debated.

Purpose of the Study:

• To investigate the specific function of Olfr78 in CB glomus cells.
• To determine if Olfr78 is essential for the hypoxic ventilatory response (HVR).

Main Methods:

• Generated a conditional Olfr78 knockout mouse strain targeting glomus cells (TH-Olfr78 KO mice).
• Assessed HVR in TH-Olfr78 KO mice.
• Analyzed molecular, electrophysiological, and biochemical properties of glomus cells from TH-Olfr78 KO mice.

Main Results:

• TH-Olfr78 KO mice exhibited a normal HVR.
• Glomus cells in TH-Olfr78 KO mice showed molecular and electrophysiological alterations.
• Reduced dopamine content and neurosecretory activity were observed in TH-Olfr78 KO glomus cells, resembling neuroblasts.

Conclusions:

• Olfr78 is not essential for CB oxygen sensing or HVR.
• Olfr78 signaling is crucial for the maturation of CB glomus cells.
• Olfr78 plays a role in maintaining glomus cell neurosecretory function.