Related Experiment Video
Updated: Sep 20, 2026

Presynaptically Silent Synapses Studied with Light Microscopy
Published on: January 4, 2010
Transmitter modulation of slow, activity-dependent alterations in sodium channel availability endows neurons with a
David B Carr1, Michelle Day, Angela R Cantrell
1Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
Abstract:
Voltage-gated Na+ channels are major targets of G protein-coupled receptor (GPCR)-initiated signaling cascades. These cascades act principally through protein kinase-mediated phosphorylation of the channel alpha subunit. Phosphorylation reduces Na+ channel availability in most instances without producing major alterations of fast channel gating. The nature of this change in availability is poorly understood. The results described here show that both GPCR- and protein kinase-dependent reductions in Na+ channel availability are mediated by a slow, voltage-dependent process with striking similarity to slow inactivation, an intrinsic gating mechanism of Na+ channels. This process is strictly associated with neuronal activity and develops over seconds, endowing neurons with a novel form of cellular plasticity shaping synaptic integration, dendritic electrogenesis, and repetitive discharge.
Related Concept Videos
Excitatory and Inhibitory Effects of Neurotransmitters
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Action Potentials
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Long-term Potentiation
Hebbian LTP
LTP can occur when presynaptic neurons...

