Synaptic scaling is a form of homeostatic plasticity that stabilizes the activity of neurons and circuits, but the mechanisms that underlie early and late synaptic scaling are incompletely understood. It has recently been found that synaptic scaling can be induced rapidly (within 4 hours) by changes in postsynaptic firing and somatic calcium influx (Ibata et al., 2008), but paradoxically that prolonged (48 hr) synaptic scaling also depends on signaling of the glial-derived cytokine TNFα (Stellwagen et al., 2006).

Whether this TNFα signaling is required for the induction of synaptic scaling, or the maintenance of synaptic properties necessary for the expression of synaptic scaling, is unknown. To address this we examined the necessity of TNFα signaling for the early and late phases of synaptic scaling, by using a combination of physiology and cellular tools in cortical culture from post natal rat.

Role of glial-derived cytokine TNFα in synaptic scaling

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Turrigiano, GG., 2008.
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