Activity-dependent long-term depression of electrical synapses.

Area of Science:

• Neuroscience
• Synaptic Plasticity
• Neuronal Networks

Background:

• Use-dependent synaptic plasticity is well-understood at chemical synapses.
• The role of natural activity in modulating the strength of electrical synapses is largely unknown.
• The thalamic reticular nucleus (TRN) utilizes electrical synapses and is crucial for attention and arousal states.

Purpose of the Study:

• To investigate activity-dependent plasticity at electrical synapses within the TRN.
• To determine if coordinated neuronal firing affects the strength of gap-junctional communication.

Main Methods:

• Electrophysiological recordings from pairs of coupled TRN neurons.
• Induction of coordinated burst firing patterns.
• Measurement of changes in gap-junctional communication strength.

Main Results:

• Coordinated burst firing induced long-term depression (LTD) at electrical synapses.
• The observed changes in gap-junctional communication were asymmetrical.
• Synaptic modification depended on the direction of neuronal activity.

Conclusions:

• Activity-dependent modification of electrical synapses is a viable mechanism.
• Asymmetrical plasticity suggests direction-dependent regulation of neuronal network connectivity.
• This plasticity may underlie dynamic network reorganization in the TRN and other electrically coupled networks.