sAPPα Inhibits Neurite Outgrowth in Primary Mouse Neurons via GABA B Receptor Subunit 1a

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Neurite outgrowth is critical for forming neural circuits.
• Secreted factors and receptors regulate neurite outgrowth.
• Amyloid precursor protein alpha (sAPPα) influences neurite outgrowth.

Purpose of the Study:

• Investigate if the interaction between sAPPα and GABA_B receptor subunit 1a (GABA_BR1a) regulates neurite outgrowth.
• Determine the role of GABA_BR1a in mediating sAPPα's effects on neurite outgrowth.

Main Methods:

• Primary hippocampal neuron cultures from wildtype and GABA_BR1a knockout mice.
• Treatment with GABA_BR agonist (baclofen) and antagonist (CGP54626).
• Application of sAPPα and an APP 17mer peptide.

Main Results:

• GABA_BR activation reduced axon length; antagonism increased it.
• GABA_BR1a knockout neurons showed increased axon length and blocked baclofen's effect.
• sAPPα and APP 17mer peptide reduced axon length in wildtype but not GABA_BR1a-deficient neurons.

Conclusions:

• GABA_BR1a mediates the inhibitory effects of sAPPα on neurite outgrowth.
• This interaction plays a role in neural development and neurodevelopmental disorders.
• Findings offer insights into Alzheimer's disease mechanisms involving APP signaling.