DMSC students attend prestigious neuroscience conference, receive high acclaim for research

The human brain is incredibly complex. With roughly one hundred billion neurons and one hundred trillion synapses, it can stump even the best scientists’ efforts to see what’s happening during periods of development, disease, and injury.

But two graduate students from the University of Victoria, Juan Trivino and Cristina Pinar, have each begun to capture these changes in more vivid, more accurate detail. Their results are already advancing our knowledge of the brain in important ways – and others are taking notice.

jtTrivino and Pinar are both Ph.D. candidates in UVic’s Division of Medical Sciences. Trivino recently developed a new method for observing structural changes in juvenile brains, while Pinar is studying how Mild Traumatic Brain Injury affects the rapidly evolving brains of youths.

In November, they presented their research at the Society of Neuroscience Annual Meeting – the largest neuroscience conference in the world.

“I loved the experience,” said Trivino. “It was especially gratifying to discover that people were interested in my research.”

Trivino is particularly interested in observing changes to dendritic spines. These tube-like structures are some of the smallest, but most important, parts of the brain’s neurons: they’re the sites where neurons “talk” to one another via neurochemical signals. To study spines, scientists normally perfuse brains with a solution of paraformaldehyde, to retain the brain’s life-like shape; the brain is then cut into thin sections so that individual cells can be examined. But this perfusion process can interfere with special chemical dyes that, when injected into the brain tissue, light up neuronal structures – including dendritic spines. This interference can result in poor-resolution images, leading to few or no useful insights about the structures being studied.

To solve this, Trivino concocted a lower-concentration paraformaldehyde solution (1.5% versus the standard 4%) to perfuse the brains. He then placed tiny crystals of a special fluorescent dye, called Di-I (and pronounced “dye-eye”), into discrete areas of mildly fixed brain slices. Together, these techniques provided Trivino with exceptionally high-quality images of dendritic spines.

And the results, according to Trivino’s supervisors – Dr. Brian Christie, Professor, and Dr. Patrick Nahirney, Associate Professor, both with the Division – have been consistently excellent.

“Juan’s novel technique has led to better, clearer, more reliable results for observing changes in the brain,” said Christie. “The images he’s been getting are spectacular – to the point where other researchers at the conference were asking him to publish his protocol because they want to use this new technique.”

cpPinar, also supervised by Christie, is studying how the juvenile brain is affected by Mild Traumatic Brain Injury (mTBI), more commonly known as concussion. Her studies are showing that repeated concussions, even mild ones, can result in long-lasting brain damage – especially in the hippocampus, the structure involved in learning and memory. In the still-developing brains of youth, the effect could be more serious: a permanent, life-long reduction in the brain’s overall capacity. Indeed, Pinar has found in models that repeat mild concussions impaired short-term spatial memory and the hippocampus’s neuronal efficiency – an effect that’s observed even after a seven-day recovery period.

“Cristina’s work is some of the first to show that concussions can produce quantifiable deficits in the way neurons talk to one another,” said Christie. “This will allow us to rigorously investigate how proteins and molecular cascades involved in synaptic plasticity are impacted in a brain that is otherwise devoid of any gross structural damage.”

To attend a conference as prestigious as the Society for Neuroscience Annual Meeting is an important part of any student’s education. But Trivino and Pinar attracted significant attention this year, said Christie. Whereas most researchers can expect to attend their posters for an hour, both students were answering questions non-stop for the full four-hour presentation block.

“It’s testament to the importance of their work and the passion they have for it,” said Christie. “Supervisors want their students to develop their own intellect, to be independent. That’s what Juan and Cristina have done, are continuing to do, and it’s resulting in truly exciting research.”