UNews - Dr. Michael Kyweriga

Investigating the causes of tinnitus

caroline.zentner — Mon, 11 Mar 2019 22:26:21 +0000

��Ѹ��Դ��߿�Ƭ of Lethbridge Post-Doctoral Fellow, Dr. Michael Kyweriga is expanding our current understanding of the cortical changes behind the development of tinnitus. Dr. Kyweriga’s current research at the ��Ѹ��Դ��߿�Ƭ of Lethbridge focuses on utilizing in-vivo mouse models and real-time brain activity monitoring technology to research the underlying cause of tinnitus.

Tinnitus is a debilitating auditory disorder characterized by an intrusive, illusory buzzing or ringing sound that persists typically following exposure to very loud sounds, such as rock concerts, shooting guns, or industrial noise. Specifically, in police and military veterans there is a higher incidence of the disorder compared to the general population. When asked about his inspiration for his research, Dr. Kyweriga described his time serving as a US Navy Hospital Corpsman with infantry marines in the desert of southern California where he was trained in combat first aid, triage, minor surgeries, medications, and the administering of hearing tests to soldiers suffering from tinnitus.

Seeing the effects of tinnitus first hand in his friends and patients, led Dr. Kyweriga to pursue this avenue of research in order to understand the underlying causes of the disorder and investigate potential avenues of therapy for military veterans and police personnel.In extreme cases, the illusory sounds estimated to range between 60-80 decibels, similar to the level of a chainsaw or vacuum cleaner. It is important to understand this disorder to properly treat patients and prevent it from worsening.

There are three main hypotheses on the cause of tinnitus, each with evidence to support and refute them. Dr. Kyweriga has focused his efforts on the Central Gain hypothesis, which postulates that following cochlear damage caused by a trauma sound, the lack of signals sent to the brain from the cochlea causes increased spontaneous brain activity and the remapping of brain areas. These brain changes are comparable to phantom limb syndrome, which is described as illusory pain experienced after the loss of a limb.

Though there have been few concrete studies on this hypothesis, Dr. Kyweriga aims to utilize real-time observation of brain activity using a cranial window and activity dependent, fluorescent cell markers. By monitoring this brain activity before, during, and after traumatic sound exposure, Dr. Kyweriga will observe the changes in cortical maps and further explore the Central Gain hypothesis. He has plans to transition from the initial animal model to human participants in the future. Utilizing EEG and MRI technology to study tinnitus in human patients, Dr. Kyweriga hopes that his research will one day benefit afflicted military veterans, police personnel, and other tinnitus sufferers, to allow them an improved quality of life.

U of L establishes Office of Post-Doctoral Affairs

caroline.zentner — Thu, 01 Feb 2018 17:58:06 +0000

Post-doctoral fellows at the ��Ѹ��Դ��߿�Ƭ of Lethbridge will soon have a new administrative home with the establishment of the Office of Postdoctoral Affairs.

“We’ve had post-doctoral fellows on this campus for a number of years now,” says Dr. Robert Wood, dean of Graduate Studies and Post-Doctoral Affairs. “In the past, they were considered trainees. That changed recently with the passing of Bill 7 and now they are considered employees, creating some needs institutionally to provide further accommodation.”

Dr. Robert Wood

The U of L typically has between 35 and 50 post-docs (PDFs) on campus at any given time. Most are paid through a faculty member’s research grant but they may also be funded independently. They, along with graduate students, form the backbone of research activity at research-intensive universities like the U of L.

“Post-docs have had some difficulties in the past accessing campus services in an appropriate way and they’re becoming a larger and more important aspect of our community,” says Wood. “This office will help give some foundation to the kind of experience that we need to be able to provide to them. It’s not just about getting them here; it’s also about, once they’re here, making sure they have a stellar experience.”

Dr. Erasmus Okine

“Post-doctoral fellows are the next in line learning the trade to become an academic,” says Dr. Erasmus Okine, vice-president (research). “Top-class ��Ѹ��Դ��߿�Ƭ and professors looking for positions tend to look for universities with strong post-doctoral fellows and strong graduate programs because they can recruit them into their research programs and they form the basis of the next wave of ��Ѹ��Դ��߿�Ƭ in our universities.”

Woods agrees that many PDFs aspire to academic careers but adds that a growing number pursue careers in industry and non-academic organizations in the public sector. The Office of Postdoctoral Affairs will help ensure their experience and training sets them up for success in any career trajectory they choose.

Dr. Gerlinde Metz, a professor of neuroscience and a Tier 1 Board of Governors Research Chair, first came to the U of L as a post-doctoral fellow. She was funded through what was then known as the Alberta Heritage Foundation for Medical Research (now Alberta Innovates-Health Solutions) as a post-doc and then was a senior scholar from 2003 to 2015.

Dr. Gerlinde Metz

“The opportunities and facilities of the Canadian Centre for Behavioural Neuroscience and the funding provided by AHFMR at that time helped me make the decision to stay at the U of L,” says Metz.

Dr. Michael Kyweriga

“Because there are so many granting agencies and different contracts for post-doctoral fellows, having the Office of Post-Doctoral Affairs will be very useful to improving the life of a post-doc,” says Dr. Michael Kyweriga, president of the U of L Post-Doctoral Association (ULPA). “We really appreciate the proactive approach Dean Robert Wood takes to ensure our post-doctoral fellowships go smoothly.”

The Office of Post-Doctoral Affairs will be housed in Research Services and supervised by Wood.

While most post-docs work in science departments, others from social sciences and humanities disciplines have also completed fellowships at the U of L.

“It’s something that I’d like to see expand across the faculties and disciplines,” says Wood.

Auditory research study to further tinnitus knowledge

caroline.zentner — Thu, 23 Jun 2016 15:29:26 +0000

In the quest to learn more about the brain and brain diseases, Dr. Majid Mohajerani has been assembling a team of researchers—three graduate students, three post-doctoral researchers, a research associate and two technicians—as he’s been building a state-of-the-art optical imaging lab.

Dr. Michael Kyweriga is one of the post-doctoral researchers and he’s investigating tinnitus. He’s currently conducting a study to determine if the parietal association area of the brain is involved in a task that requires a transgenic mouse to discriminate between two auditory tones.

Dr. Michael Kyweriga

“Many people are aware of the cocktail party effect, which is when you’re in a noisy environment and you’re talking to your friend but there’s all these distracting sounds. You are able to tune out those distracting sounds. That’s a form of attention called top-down control, where you try to suppress other inputs and pay attention to what your friend is saying. How the brain does this is not well understood,” he says.

Researchers like Kyweriga have some candidate regions of the brain that might be involved, one of them being the parietal association area. At a cocktail party, a person’s ears receive information about the sounds in the environment. The signals travel on the auditory nerves and on to the brain’s auditory cortex for further processing.

“When the signals get up into the cerebral cortex—the wrinkly, thinky part of the brain—that’s where we start assigning meaning to sounds, identifying songs or a person’s voice. Beyond that are these association areas that are now starting to draw in memories and accessing other parts of the brain that pull all this together,” says Kyweriga. “We’re trying to deal with the information as we try to listen to a friend speak and some people will close a door or put their dominant ear closer to the person to cut out other distractors.”

How people are able to direct their attention through top-down control, by willing themselves to pay attention, has eluded scientists for a long time. Some scientists have speculated that tinnitus could be a disorder of top-down control. If Kyweriga can show that the parietal association area is involved in top-down control, then he can test whether tinnitus is the result of faulty top-down control. Only with the tools in Mohajerani’s lab can these hypotheses be tested.

Kyweriga is training mice to learn whether a high- or low-frequency tone is associated with a reward. Once the mice have been sufficiently trained, a fibre optic connector is implanted close to the surface of their brains. To test his hypothesis, the mice do the auditory task again.

“While they’re doing the task and, simultaneously with them getting the sound, we’re going to turn on the blue light and that should either disrupt or enhance their neural responses to the sound,” says Kyweriga. “This is a really cool set of experiments that we’re able to do here with all the technology that we have and get to answering these long-standing questions we have in neuroscience about how our brains are able to do these type of things.”

As researchers like Kyweriga uncover more of the secrets of how the brain works, the higher is the likelihood of developing therapeutic approaches that will help people with tinnitus.

While Kyweriga uses lasers to alter the behaviour of his mice subjects, another post-doctoral researcher, Dr. Maurice Needham, uses lasers to view neuronal activity and provides expertise on the technical side of things. He’s in charge of making sure the optical equipment runs properly, including the two new shiny two-photon microscopes placed on a stainless steel table that’s suspended on air.

Dr. Maurice Needham

“The reason it’s suspended on air is to eliminate vibrations because when you have so many components working so finely, you have to ensure that any minor movements emanating from the building will be absorbed by this table. Any vibrations from the ground first have to move the heavy stainless steel table and even if that happens, the air cushion protects the stability of the tabletop and thus the images,” says Needham. “When it comes to two-photon imaging, this is probably the most advanced system you can buy.”

Needham has been at the U of L for five years and during that time he’s become more familiar with imaging systems. When the two-photon microscopes were installed, Needham watched, listened and learned so now he’s in charge of making sure they continue to work and performing any necessary repairs.

“Once Majid started increasing the amount of imaging systems here, we connected because I was interested,” he says.

While two-photon systems have been available for years, Mohajerani’s system is special. In addition to being very fast, it can simultaneously stimulate specific brain regions while viewing the subsequent response. It can also look much deeper into brain tissue than previous systems. This will be of great benefit to many experiments in Mohajerani’s lab, including Kyweriga’s work on tinnitus.

“All research requires the sharing of data. Seeing numbers and graphs is one thing but seeing pretty images is always the best. A picture is worth a thousand words,” says Needham. “We are one of only two labs in Canada with this imaging set-up, making us competitive on the world stage for neuroscience research. These systems, along with the new two-photon tomography system, will elevate this research centre’s technical abilities to compete with the best universities in the world.”

UNews - Dr. Michael Kyweriga

Investigating the causes of tinnitus

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Auditory research study to further tinnitus knowledge

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