Rapid Synaptic Scaling Induced by Changes in Postsynaptic Firing

Three other studies failed to observe local enhancement of AMPAR accumulation at inactivated synapses.

“In contrast, three other studies failed to observe such a local enhancement of AMPAR accumulation at inactivated synapses.”

Selectively blocking postsynaptic firing in neocortical neurons scales synapses up through a process that requires a drop in somatic calcium influx, reduced activation of CaMKIV, and transcription.

“Selectively blocking postsynaptic firing in neocortical neurons scales synapses up through a process that requires a drop in somatic calcium influx, reduced activation of CaMKIV, and transcription (Ibata et al. 2008).”

Selectively blocking firing by microperfusion of TTX to the soma of individual neurons scales up synaptic strengths to the same degree as blockade of network activity, whereas local block of synaptic transmission does not induce a local enhancement of receptor accumulation.

“Selectively blocking firing by microperfusion of TTX to the soma of individual neurons scales up synaptic strengths to the same degree as blockade of network activity, whereas local block of synaptic transmission does not induce a local enhancement of receptor accumulation (Ibata et al. 2008).”

There is strong evidence that synaptic scaling is a cell-autonomous process induced by changes in a neuron's own firing.

“there is strong evidence that synaptic scaling is a cell-autonomous process induced by changes in a neuron's own firing.”

Scaling is a gradual and cumulative process evident after as little as 4-6 h of activity blockade.

“Inconsistent with the above model is the observation that scaling is a gradual and cumulative process evident after as little as 4-6 h of activity blockade (Sutton et al. 2006;Ibata et al. 2008), whereas TNFa-dependent scaling was only observed after prolonged activity block (48 h) (Stellwagen and Malenka 2006).”