A new study published in Nature Medicine provides evidence from human brain tissue. Researchers analyzed nearly half a million cell nuclei from postmortem hippocampal tissue, integrating gene expression, chromatin accessibility and protein data to examine how cells and neurogenic processes differ in major depressive disorder.

The researchers identified a neurogenic lineage in the adult human hippocampus and found evidence that the process of new-neuron development was stalled in major depressive disorder. They also identified changes involving cellular stress, synaptic plasticity, metabolism, immune signaling and the balance between excitatory and inhibitory activity.

Why it matters: The findings strengthen evidence that adult neurogenesis occurs in the human hippocampus and provide a more detailed picture of how hippocampal plasticity may be disrupted in depression. The work may also help researchers identify biological pathways worth investigating as potential treatment targets.

Important context: This was a postmortem human brain-tissue study. It identifies biological differences associated with major depressive disorder, but it does not show that impaired neurogenesis alone causes depression or establish a new treatment.

René Hen, Ph.D., Columbia University, a co-author of the study is a member of HDRF’s Depression Task Force.

Source: Dysregulated adult hippocampal neurogenesis in major depressive disorder, Nature Medicine.