Coming Undone: How Stress Unravels The Brain's
Structure
March 4, 2009
The helpless behavior that is commonly linked to depression and post-traumatic
stress disorder (PTSD) is preceded by stress-related losses of
synapses-microscopic connections between brain cells-in the brain's hippocampal
region, researchers at Yale School of Medicine report in the March 1 issue of Biological
Psychiatry.
The team used a six-day treatment with the antidepressant desipramine to reverse
helpless behavior and restore hippocampal synapses in rats.
"In clinical practice, the main problem with antidepressants is that they
require weeks to exert their effect," said lead scientist on the project
Tibor Hajszan, M.D., associate research scientist in the Department of
Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine.
"Because there are ways to restore these lost hippocampal synapses in as
little as hours or even minutes, our laboratory is currently testing
rapid-acting antidepressants that could provide immediate relief from depressive
symptoms."
Mental health disorders, including depression, are rapidly becoming the second
largest public health problem, said Hajszan. "This is magnified by the fact
that current antidepressant drugs remain ineffective in the majority of
patients," he said.
Researchers have suspected for years that changes in synapses may play a role in
depression neurobiology. In this study, Hajszan and his team studied helpless
behavior in rats and used electron microscopy to analyze directly what happens
to hippocampal synapses in the presence or absence of helpless behavior.
"Because synapses have the potential for rapid response, synapse loss
probably underlies the rapid deterioration of mood that depressed patients
sometimes experience," said Hajszan. "Thus, it is possible to elevate
mood rapidly by generating new hippocampal synapses, which is attainable by
certain drugs we are testing."
Other authors on the study included Antonia Dow, Jennifer L. Warner-Schmidt,
Klara Szigeti-Buck, Nermin L. Sallam, Arpad Parducz, Csaba Leranth and Ronald S.
Duman.
Link:
Tibor Hajszan
http://www.med.yale.edu/obgyn/research/researchlabs.html
YALE
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