CKAMP44 modulates integration of visual inputs in the lateral geniculate nucleus

Area of Science:

• Neuroscience
• Synaptic Plasticity
• Visual System Function

Background:

• Relay neurons in the dorsal lateral geniculate nucleus (dLGN) receive input from retinal ganglion cells (RGCs).
• Retinogeniculate synapses exhibit short-term depression of AMPA receptor (AMPAR)-mediated currents, but mechanisms remain unclear.

Purpose of the Study:

• To identify the molecular mechanisms underlying short-term depression at retinogeniculate synapses.
• To investigate the functional role of CKAMP44 in synaptic transmission and visual integration.

Main Methods:

• Electrophysiological recordings in dLGN relay neurons.
• Genetic manipulation using CKAMP44 knockout (CKAMP44-/-) mice.
• In vivo electrophysiological recordings of dLGN neuronal activity.

Main Results:

• CKAMP44 identified as an AMPAR auxiliary subunit in dLGN relay neurons.
• CKAMP44 reduces AMPAR recovery from desensitization, causing synaptic short-term depression.
• CKAMP44 deletion abolishes depression, increasing dLGN neuron spike probability with high-frequency input.
• CKAMP44-/- mice show augmented ON- and OFF-responses in dLGN neurons.

Conclusions:

• CKAMP44 is critical for regulating synaptic short-term depression at retinogeniculate synapses.
• CKAMP44 modulates visual input integration by controlling dLGN neuron excitability.
• Targeting CKAMP44 offers potential for understanding and treating visual processing disorders.