Table 1.

Astrocytic factors that control different aspects of synaptic development

Molecule	Action	Findings	References
Structural synapse formation
Thrombospondin	Positive	Induces glutamatergic synapse formation; secreted by astrocytes	Christopherson et al. 2005; Eroglu et al. 2009; Xu et al. 2009a; Garcia et al. 2010; Hughes et al. 2010
Hevin (SPARC-like 1)	Positive	Induces glutamatergic synapse formation; secreted by astrocytes	Kucukdereli et al. 2011
γ-Protocadherins	Positive	Induces glutamatergic and GABAergic synapse formation; contact mediated	Garrett and Weiner 2009
BDNF	Positive	Induces glutamatergic synapse formation; secreted by vestibular support cells	Gómez-Casati et al. 2010
TGF-β	Positive	Induces glutamatergic synapse formation; regulates synapse maturation	Diniz et al. 2012; Fuentes-Medel et al. 2012
Estrogen	Positive	Induces glutamatergic synapse formation	Hu et al. 2007
SPARC	Negative	Inhibits glutamatergic synapse formation; antagonist of hevin	Kucukdereli et al. 2011
Presynaptic function
Cholesterol	Positive	Increases presynaptic strength and release probability	Mauch et al. 2001; Goritz et al. 2005
Thrombospondin	Negative	Inhibits presynaptic release at glutamatergic synapses	Crawford et al. 2012
SPARC	Negative	Inhibits presynaptic maturation at cholinergic nerve terminals	Albrecht et al. 2012
Postsynaptic function
Glypican 4,6	Positive	Increases synaptic AMPA receptors; induces glutamatergic synapse formation	Allen et al. 2012
ECM	Positive	Stabilizes AMPA receptors at synapses	Frischknecht et al. 2009; Pyka et al. 2011
ADNF	Positive	Increases synaptic NMDA receptors	Blondel et al. 2000
TNF-α	Positive and negative	Increases synaptic AMPA receptors; decreases synaptic GABAA receptors	Beattie et al. 2002; Stellwagen et al. 2005; Stellwagen and Malenka 2006; Steinmetz and Turrigiano 2010; Hennekinne et al. 2013
Thrombospondin	Positive and negative	Increases synaptic glycine receptors; decreases synaptic AMPA receptors
SPARC	Negative	Decreases synaptic AMPA receptors	Jones et al. 2011

ADNF, activity-dependent neurotrophic factor; BDNF, brain-derived neurotrophic factor; GABA_A, γ-aminobutyric acid; NMDA, N-methyl-d-aspartate; SPARC, secreted protein acidic, rich in cysteine; TNF-α, tumor necrosis factor α.