Functional interactions between steroid hormones and neurotrophin BDNF

Figure 2 Glucocorticoids depressed BDNF-induced release of glutamate and expression of GR in cultured cortical neurons. A: Dose-dependent inhibitory effect of corticosterone pretreatment on BDNF-induced glutamate release. Corticosterone (0.001-10 μmol/L) was applied at DIV4. Forty-eight hours later, BDNF (100 ng/mL, 1 min) was added and released glutamate was measured by HPLC. Prior to performing the BDNF application, samples were collected without stimulation as the basal release (1 min). Con means no application of corticosterone. Data represent mean ± SD (n = 4). ^bP < 0.001 vs basal, ^dP < 0.01, ^fP < 0.001 vs BDNF-induced release in Con (t-test); B: Endogenous expression of glucocorticoid receptor (GR) was decreased after corticosterone (0.01-10 μmol/L) was applied at DIV4. Forty-eight hours later, cell lysates were collected for western blotting. Endogenous expression of TrkB was unchanged after exposure to corticosterone. Levels of TUJ1 (class III β-tubulin), a neuronal marker, are shown as control.