What makes us human, and where does this mysterious property of
“humanness” come from? President and Professor Rusty Gage, along
with co-first author Carol Marchetto and colleagues, developed a
strategy to more easily study the early development of human neurons
compared with the neurons of nonhuman primates. The research offers
scientists a novel tool to construct an evolutionary tree of multiple
primate species to better understand the evolution of the human brain.
EVOLUTION OF THE BRAIN
In two recent editions of
first author Krishna Vadodaria and collaborators
showed why selective serotonin reuptake inhibitors
(SSRIs), a common treatment for major depressive
disorder that increases the neurotransmitter serotonin,
do not work in some patients. The discoveries could help
lead to more personalized treatments for depression
as well as other psychiatric conditions, such as bipolar
disorder and schizophrenia.
In the first study, published in January, the researchers
created neurons from skin cells from patients whose
depression did not show signs of improving with SSRIs.
The team discovered that these patient-derived neurons
became hyperactive when serotonin levels increased,
compared with cells derived from healthy individuals or
those who respond to SSRIs.
InMarch, a second paper by the group demonstrated that
neurons from SSRI-resistant patients had longer neuron
projections than did neurons from SSRI-responders,
along with low levels of key genes involved in forming
DO NOT WORK FOR
A stylized microscopy image of forebrain neural
progenitor cells from chimpanzees.The image
represents the work’s potential for offering insights
into the evolution of the primate tree of life.
Image credit: Salk Institute/Carol Marchetto/
Ana P.D. Mendes
From left: Amy Le, Kelly Heard, Rusty Gage,
Krishna Vadodaria and Carol Marchetto.
10 INSIDE SALK