CFTR Modulates Hypothalamic Neuron Excitability to Maintain Female Cycle.

Area of Science:

• Neuroscience
• Endocrinology
• Ion Channel Physiology

Background:

• Cystic fibrosis transmembrane conductance regulator (CFTR) is primarily known as an epithelial chloride channel.
• Emerging evidence suggests CFTR expression in the nervous system, but its role in neuronal excitability remains largely unknown.
• CFTR's known association with fertility prompted an investigation into its function in the hypothalamus.

Purpose of the Study:

• To investigate the role of CFTR in regulating hypothalamic neuron excitability.
• To determine if CFTR dysfunction contributes to reproductive abnormalities observed in cystic fibrosis.

Main Methods:

• Patch-clamp electrophysiology and calcium imaging in primary rat hypothalamic neurons.
• Electrophysiological recordings in brain slices from wild-type and CFTR-mutated (DF508) mice.
• In vivo calcium imaging using fiber photometry (GCaMP6s) in female mice during different estrous cycle phases.

Main Results:

• Pharmacological inhibition of CFTR induced electrical pulses and Ca2+ spikes in rat hypothalamic neurons, dependent on extracellular chloride.
• Hypothalamic neurons from CFTR-mutated mice showed reduced electrical activity compared to controls.
• In vivo studies revealed diminished estrus-associated hypothalamic activity in CFTR-mutated mice, correlating with delayed puberty and disrupted cycles.

Conclusions:

• CFTR plays a critical role in modulating hypothalamic neuron excitability.
• CFTR dysfunction contributes to the reproductive disturbances, including altered estrous cycles and reduced fertility, seen in cystic fibrosis patients.
• Targeting CFTR may offer therapeutic potential for reproductive issues associated with CFTR mutations.