TRPC3 channels are required for synaptic transmission and motor coordination

Area of Science:

• Neuroscience
• Molecular Biology
• Physiology

Background:

• Slow synaptic excitation in the mammalian central nervous system relies on metabotropic glutamate receptors (mGluRs).
• Transient Receptor Potential C1 (TRPC1) channels were previously hypothesized to mediate this excitation.
• Previous studies lacked definitive evidence for TRPC1's role.

Purpose of the Study:

• To identify the specific Transient Receptor Potential (TRP) channel involved in mGluR-dependent synaptic signaling.
• To investigate the role of TRPC3 in cerebellar Purkinje cells.
• To determine the functional consequences of TRPC3 deficiency on motor behavior.

Main Methods:

• Analysis of TRPC1-deficient mice.
• Electrophysiological recordings in mouse cerebellar Purkinje cells.
• Generation and behavioral testing of TRPC3 knockout mice.

Main Results:

• TRPC1 deficiency did not impair mGluR-dependent synaptic signaling.
• TRPC3 is the predominant TRPC subunit in Purkinje cells.
• TRPC3 knockout mice completely lacked slow synaptic potentials and mGluR-mediated inward currents.
• Synaptic Ca2+ release from intracellular stores remained unaffected in TRPC3 knockout mice.
• TRPC3 knockout mice exhibited impaired walking behavior.

Conclusions:

• TRPC3 channels are essential for mGluR-dependent synaptic transmission in cerebellar Purkinje cells.
• TRPC3 functions as a postsynaptic channel mediating synaptic signaling.
• TRPC3 plays a critical role in motor coordination.