What is role of NE and serotonin in BDNF synthesis?

Serotonin and NE aid in BDNF synthesis, which is important for cell development and if inactivated leads to cell death So neurogenesis is upregulated by BDNF enriched environment, exercise, learning and antidepressants, and is downregulated by stress, adrenal steroids, age and drugs of abuse. Antidepressants may normalize BDNF levels promoting serotonin and NE conduction