Zika virus was first isolated in rhesus macaque monkeys in Uganda in
1947. Transmitted by mosquito, it is related to several other human
pathogens, including West Nile virus, dengue, Japanese encephalitis
virus and yellow fever.
As widely reported, the 2015 Zika epidemic in
Brazil coincided with a dramatic increase in cases of microcephalic
‘In early postnatal Zika-infected models some brain areas and cell types showed particularly large increases in apoptosis that was not observed in older animals.’
In a study that could one day help eliminate the tragic birth defects
caused by Zika virus, scientists from the Florida campus of The Scripps
Research Institute (TSRI) have elucidated how the virus attacks the
brains of newborns. This information could accelerate the development of
The study, led by TSRI Associate Professors Hyeryun Choe and Damon Page, was published recently in the journal Nature Scientific Reports
In the new study, the scientists observed the virus's effects in
animal models at two different points - during early postnatal
development, when the brain is growing rapidly, and at weaning, when the
brain has largely reached adult size.
"In early postnatal Zika-infected models some brain areas and cell
types showed particularly large increases in apoptosis [programmed cell
death] that we did not observe in older animals," Choe said.
The findings expand the current knowledge of cell types vulnerable
to the effects of Zika infection to include not only neuron progenitor
cells, but also post-mitotic neurons that have finished dividing but are
still are undergoing rapid increases in cell size. These results are
consistent with the theory that periods of rapid brain growth are
especially susceptible to the damaging neurodevelopmental effects of
"An interesting aspect of the study is the comparison of the two
time points," Page noted. "There is neural cell death at both times, but
it's much greater when the brain is growing rapidly. We can take
advantage of this strong effect to test potential treatments and to
understand whether some genetic backgrounds may confer enhanced
susceptibility or resilience to Zika-induced microcephaly."
"Our findings establish a valuable model to investigate the
mechanisms that underlie the horrific birth defects associated with Zika
infection," said TSRI Graduate Student Wen-Chin Huang, the first author
of the study.
The team is continuing to build on this study to better understand and combat the virus.