Supplementary Figure 9: Schematics of proposed mechanism of BDNF upregulation in the VTA-NAc circuit in the context of social stress.
From: Stress and CRF gate neural activation of BDNF in the mesolimbic reward pathway
(a) Schematic showing that stress gates the up-regulation of BDNF signaling in NAc by working together with phasic firing of VTA DA neurons that project to NAc as well as CRF actions in NAc, which may be both pre- and postsynaptic. (b) Schematic illustrating proposed interactions of BDNF and CRF in promoting stress susceptibility. Our data suggest that stress-induced CRF signaling in NAc activates its receptors located presynaptically on terminals of VTA DA neurons and works together with arriving phasic spikes from these DA neurons to release BDNF. BDNF then activates TrkB receptors located on NAc medium spiny neurons to promote susceptibility. Direct postsynaptic actions of CRF on these medium spiny neurons might also contribute to susceptibility.
