from the world's big
Treatable brain inflammation may be behind tinnitus
Scientists may have seen a way to cure a maddening symptom of hearing loss.
- A treatment for tinnitus – a constant ringing in the ears – has been frustratingly elusive.
- Out-of-control inflammation, the brain's response to damage, may be the cause of long-term ringing in the ears.
- A study that examined mice with noise-induced hearing loss seems to have found the neural trigger for tinnitus.
Common, or subjective, tinnitus is no fun. If you have it, you know what we mean. And a lot of people do — some 500 million worldwide. It's a byproduct of hearing loss that produces a constant veil of high-frequency pitches that never abates. For sufferers, there is no silence, ever. Unfortunately, identifying its cause, much less a treatment, has proven elusive. Now, however, a new study published in PLOS Biology may have uncovered the physiological mechanism behind it: neuroinflammation in the auditory cortex. And it could be treatable.
Note the "may" in the paragraph above. It's there because this study draws its conclusions based on the physiology of rodent test subjects, not humans, and things don't always translate between species. Hence, its claims deserve a grain or two of salt. Ethics issues aside, this is often the case with exciting-sounding medical-breakthrough news. It's so common, in fact, that there's a Twitter hashtag for it: @justsaysinmice.
How to acquire tinnitus
Not that you'd want to. However, the recipe is simple: Expose your ears to overloud noise. Tinnitus is actually not an underlying condition — it's a symptom of hearing loss. Noise-induced hearing loss (NIHL) can result from, for example, working in a loud environment without protecting your ears, or attending too many loud concerts, standing too close to speakers at a show, or from listening to loud music on headphones.
The way that we hear sound is not as direct as many think. Sound is really a matter of compression waves generated by a source that compresses and releases air on its way to your ears. Tiny hairs, the stereocilia, in your ears receive these air-pressure changes and fire off signals to your brain that we interpret as sound. Each hair has the job of producing a certain range of audio frequencies, and with tinnitus, some of these hairs get stuck in what amounts to their "on" position, continually firing off these signals to your brain even without the presence of an actual external sound source. Exactly what triggers this misbehavior is what the new study attempts to explain.
Image source: Alila Medical Media/Shutterstock
The study states, "Neuroinflammation is the central nervous system's response to external and internal insults, such as infection, injury, diseases, and abnormal neural activity," and so its authors looked at mice with NIHL to assess its possible role in tinnitus. They conclude "Our results indicate that neuroinflammation plays an essential role in a noise-induced excitatory-to-inhibitory synaptic imbalance and tinnitus in a rodent model."
To protect the brain, an inflammatory response typically involves the activation of microglia, the central nervous system's primary immune cells. When they remain active in response to chronic damage — as with hearing damage — though, they tend to release proinflammatory cytokines, which can make the problem worse. In the mice studies, the authors found one such proinflammatory cytokine, TNF-α. ("TNF" stands for "tumor necrosis factor.") It seems to be the neural trigger for tinnitus.
When the researchers shut off the gene that results in the production of TNF-α in one set of mice, and likewise when they repressed it with medication in another, tinnitus disappeared. Testing the connection from the other direction, they also found that when they introduced TNF-α into the auditory cortex of normal mice and also mice who had no natural TNF-α, tinnitus appeared.
How do we know if a mouse has tinnitus?
Image source: photolinc/Shutterstock
This question, which may have occurred to you to wonder, highlights a potential problem with this study. Since tinnitus is an ever-present phenomenon, some in the research community — including the authors of this study — have embraced "gap detection" as a means of testing for the presence of the condition in animals. The idea of gap testing is that, since tinnitus is constant, an animal wouldn't be able to hear gaps between a series of audio tones being played. Gap detection is tested by monitoring an animal's acoustic startle reflex to each new tone as it sounds — in theory, an animal with tinnitus won't notice or react to each new tone. However, it's worth noting that the value of gap detection testing for tinnitus is controversial.
All that having been said, there are a number of anti-inflammatory medications, and as used in the research, genetic means of controlling the presence of TNF-α. If the authors' findings are eventually confirmed to be valid in human subjects, there may be hope for tinnitus sufferers at last.
- Tinnitus cure - Is there a cure for tinnitus? How to stop tinnitus ›
- Tinnitus: Ringing in the ears and what to do about it - Harvard Health ›
- Tinnitus is the result of the brain trying, but failing, to repair itself ... ›
- Reducing brain inflammation could treat tinnitus and other hearing ... ›
- Treating brain inflammation could help silence tinnitus ›
Educators and administrators must build new supports for faculty and student success in a world where the classroom might become virtual in the blink of an eye.
- If you or someone you know is attending school remotely, you are more than likely learning through emergency remote instruction, which is not the same as online learning, write Rich DeMillo and Steve Harmon.
- Education institutions must properly define and understand the difference between a course that is designed from inception to be taught in an online format and a course that has been rapidly converted to be offered to remote students.
- In a future involving more online instruction than any of us ever imagined, it will be crucial to meticulously design factors like learner navigation, interactive recordings, feedback loops, exams and office hours in order to maximize learning potential within the virtual environment.
A leading British space scientist thinks there is life under the ice sheets of Europa.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
Neil deGrasse Tyson wants to go ice fishing on Europa<div class="rm-shortcode" data-media_id="GLGsRX7e" data-player_id="FvQKszTI" data-rm-shortcode-id="f4790eb8f0515e036b24c4195299df28"> <div id="botr_GLGsRX7e_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/GLGsRX7e-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"></script> </div>
Water Vapor Above Europa’s Surface Deteced for First Time<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9c4abc8473e1b89170cc8941beeb1f2d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WQ-E1lnSOzc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
A study finds people are more influenced by what the other party says than their own. What gives?
- A new study has found evidence suggesting that conservative climate skepticism is driven by reactions to liberal support for science.
- This was determined both by comparing polling data to records of cues given by leaders, and through a survey.
- The findings could lead to new methods of influencing public opinion.
Mind the cues<div class="rm-shortcode" data-media_id="CabkeAzx" data-player_id="FvQKszTI" data-rm-shortcode-id="169377c88f392a86f6c42180b74820a5"> <div id="botr_CabkeAzx_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/CabkeAzx-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/CabkeAzx-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/CabkeAzx-FvQKszTI.js"></script> </div> <p>The gulf in accepting the science behind climate change also exists among party elites. It is well known to any American who is attentive to the news, as party leaders are often more than willing to discuss their take to journalists.</p><p>Using polling data going back to the 1980s, the researchers were able to create a chart showing the aggregate amount of climate skepticism among the general population. A similar diagram showing the Republicans' skepticism dating back to 2001 was sourced from a previous, similar study. It was shown to be highly correlated with the one produced for this study.</p><p>These charts were compared with media content from prominent newspapers that included implicit or explicit stances on climate change by significant political figures. These thousands of articles were classified by using key terms and which major political figures were quoted or referenced. The researchers compared the number of cues over time to measured skepticism and looked for "<a href="https://en.wikipedia.org/wiki/Granger_causality" target="_blank">Granger causality</a>," the tendency for one variable to predict the future value of another variable.</p><p>The model shows evidence of both in and out-group cue effects, though the repulsion to out-group cues was much more evident. A significant increase in Democratic cues in favor of climate science was followed by a rise in skepticism among Republican voters. Importantly, the cues lead, rather than follow opinion, and do so with consistency. Changes in view did not predict changes in the number or direction of cues. </p><p>The researchers also surveyed nearly 3000 adults to demonstrate the concept. This involved showing them a statement on the scientific consensus around climate change and a cue from either a Republican or a Democrat. This test confirmed the previous observation and provided further support for the notion that signals from leaders cause an increase in skepticism among some respondents.</p><p>Before my left-leaning and Democratic readers get too smug, this research references previous studies demonstrating a similar effect in the lead up to the Iraq War. However, in that case, the Democratic Party elites' mixed messages were countered by a Republican Party united behind the idea of invasion. The effect on the Democratic party rank and file was similar to that observed in this case. </p><p>Several other studies have examined effects similar to this for other issues. This study's importance is its focus on out-group cues and the effort placed into demonstrating a causal relationship between the statements of certain party elites and public opinion. Most previous studies focused purely on in-group cues or failed to differentiate between the two. </p>
Can thinking about the past really help us create a better present and future?
- There are two types of counterfactual thinking: upward and downward.
- Both upward and downward counterfactual thinking can be positive impacts on your current outlook - however, upward counterfactual thinking has been linked with depression.
- While counterfactual thinking is a very normal and natural process, experts suggest the best course is to focus on the present and future and allow counterfactual thinking to act as a motivator when possible.
“Upward” versus “downward” counterfactual thinking<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzQ1NDYxOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NDM2MDY2OX0.njWs1qrV1vDBxU1V75tUduUW4TjJvEHglDWsK8ZF2l4/img.jpg?width=1245&coordinates=0%2C556%2C0%2C209&height=700" id="a15fa" class="rm-shortcode" data-rm-shortcode-id="98314d4d2b256ed08f42d369fe4ae080" data-rm-shortcode-name="rebelmouse-image" alt="concept of man thinking about the past one line drawing counterfactual thinking" />
What are upward and downward counterfactual thinking?
Image by one line man on Shutterstock<p><strong>What is upward counterfactual thinking?</strong></p><p>Upward counterfactual thinking happens when we look at a scenario and ask ourselves "what if" in terms of how our life could have turned out better. </p><p>Examples of upward counterfactual thinking are: </p><ul><li><em>"I wish I had taken that other job instead of this one 10 years ago - my life would be so much better if I had." </em></li><li><em>"I wish I would have gotten the part in that high school play, maybe I could have gotten into a theatre school and became an actor…"</em> </li></ul><p>Both of these examples have the ideology that if you had made different choices, your life right now would be improved. </p><p><strong>What is downward counterfactual thinking?</strong></p><p>Downward counterfactual thinking is, naturally, the opposite of upward counterfactual thinking in that we think about how things could have been worse if other decisions had been made. </p><p>Examples of downward counterfactual thinking are: </p><ul><li><em>"I'm so thankful I studied secondary education in university instead of psychology like I had originally planned - I love teaching high school kids and I never would have gotten to do that…" </em></li><li><em>"I'm so happy I left David when I got the chance, I can't imagine still being in an unhappy marriage with someone who doesn't support me…"</em> </li></ul><p>In these examples, we see the idea that if you had made different choices your life would not be as good as it is right now. </p>
How counterfactual thinking can impact your life<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzQ1NDYxNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNjI2MDQxOX0.DIVQ-Yk0d6yE3tc743MH1Fz2pOg1TGHLmhp8dPp9UdY/img.jpg?width=1245&coordinates=0%2C0%2C0%2C0&height=700" id="522d7" class="rm-shortcode" data-rm-shortcode-id="da7df6ad916b043e3610223900d0f8df" data-rm-shortcode-name="rebelmouse-image" alt="man thinking what if written on chalkboard" />
How do upward and downward counterfactual thinking impact your life?
Photo by Brasil Creativo on Shutterstock<p>While many people don't see the point in "what if" scenarios, various studies have found that downward counterfactual thinking can be more associated with psychological health compared with upward counterfactual thinking. Not only that, but research has also shown upward counterfactual thinking can be linked with current and future depression.</p> <p><strong>Downward counterfactual thinking tends to be more associated with psychological health </strong></p><p>According to a <a href="http://journal.sjdm.org/jdm06136.pdf" target="_blank">2000 study</a>, downward counterfactual thinking can be linked with better psychological health compared to upward counterfactual thinking. More importantly, in cases where downward counterfactual thinking did lead to negative feelings, those feelings acted as something of a motivator for people to take productive actions to better their current situation. </p> <p><strong>Upward counterfactual thinking tends to be more associated with depression </strong></p><p><a href="https://www.sciencedirect.com/science/article/abs/pii/S0272735816301714#:~:text=An%20upward%20counterfactual%20(as%20opposed,Markman%20and%20McMullen%2C%202003)." target="_blank">According to a 2017 study</a> that pooled a sample of over 13,000 respondents, thoughts about "better outcomes" and regret (upward counterfactual thinking) were associated with current and future depression. </p> <p><strong>Downward counterfactual thinking can actually improve your relationships and is more often engaged in by women than men.</strong></p><p>In a <a href="https://dspace.sunyconnect.suny.edu/bitstream/handle/1951/67589/Studer_Thesis.pdf?sequence=1&isAllowed=y" target="_blank">2016 research paper submitted</a> to the Department of Psychology at the State University of New York at New Paltz, downward counterfactual thinking in regards to romantic relationships was associated with relatively positive relationship outcomes. Interestingly, women were more likely than men to engage in downward counterfactual thinking about their romantic life. </p> <p><strong>Upward counterfactual thinking can have some benefits in certain scenarios. </strong></p><p>When we look back after a failed test and think "I wish I would have studied more" - this motivates us to study harder the next time a test comes up. In this way, upward counterfactual thinking (or the negative version of "what if") can actually benefit us. </p> <p><strong>This can be difficult, though, because much of the time upward counterfactual thinking is more associated with a pessimistic outlook that can be unmotivating. </strong></p> <p>Thinking in the past tense can be motivational (and even healthy) at times, but the best thing to do is look forward. </p><p>While counterfactual thinking as a whole can be used to motivate us to make better choices or appreciate where we are in life, <a href="https://www.psychologytoday.com/us/blog/darwins-subterranean-world/201809/the-psychology-what-if" target="_blank">this Psychology Today</a> article suggests that we should come up with ways to move on and focus on the present and the future instead of the past. Using counterfactual thinking as a motivational tool can be very helpful if we don't get stuck in the "what if" mindset that tends to pull us out of the present and back into the past, where things will always remain the same. </p>