Now, a researcher says he hopes to find a cure in a very unusual place -- a fish.

Ernest Moore, an audiologist and cell biologist at Northwestern University, said the zebrafish seems to have the ability to suffer from the condition, known as tinnitus. Treatment with drugs appears to help restore electrical activity in the fish's inner ear to normal.

"If they work in clinical trials in humans, this might offer a cure," Moore said. "What we're hoping is that we could perhaps help individuals who have this intractable problem."

Moore himself is one of those people. He suffers from tinnitus, and said the cause may date back to the years when he hunted for possum with his grandfather without using ear protection.

Later, he worked as an audiologist in the U.S. Army Reserves and remembers "listening to stories about ringing in the ears and telling people why we didn't really have a cure."

Moore describes his tinnitus as sounding a bit like white noise. Others, he said, hear a pure tone in a middle frequency.

The American Tinnitus Association says many people suffer from the condition 24 hours a day. William Shatner, the "Star Trek" actor, describes his own case as creating "agonizing screeching in my head," according to the association.

"Some people have it all the time, and some people have it intermittently," Moore said. "Some people only recognize it at night, when it's quiet. You have it in one ear, and you put that ear on the pillow, and you can hear it."

Causes of tinnitus appear to include noise exposure and genetic susceptibility. The use of some pharmaceutical drugs can cause it, too.

Treatments include the use of devices that mask the noise and surgery, Moore said. Some people find relief through drugs like aspirin and steroids, he said.

Researchers have tried to study tinnitus by looking at the rat, which can develop the condition. Moore turned to the zebrafish, a tropical fish that's often found in aquariums.

Fish, like humans, have two ears, he said, and electrical activity allows the fish to hear. Moore is giving different drugs to the fish and testing how they affect neuronal activity involving hearing.

Moore said he's submitted a grant proposal to the Department of Defense, which is spending money to support research into tinnitus.

Anthony Cacace, a professor of communications sciences and disorders at Wayne State University, said the key to any research in animals is to determine that they actually hear tinnitus. Research suggests that rats and mice do, he said.

"You have to know if they have tinnitus before you treat it with drugs," he said.

Research has progressed over just the last couple of years, Cacace said, as scientists have learned new ways to gauge the effectiveness of treatments by doing a better job of monitoring the nervous systems of animals.

More information

Learn more about tinnitus from the National Institutes of Health.

Here are suggestions to help heal a ruptured eardrum, courtesy of the University of Michigan Health System:

• Follow all instructions from your doctor, and don't put anything inside your ear unless your doctor says it's OK.
• Keep water out of your ear when you take a bath or shower.
• Take an over-the-counter pain reliever such as acetaminophen or ibuprofen.
• Be gentle when blowing your nose until your ear has healed.
• Don't go swimming or submerge your ear in water until your doctor approves.

Here is information to help you prepare for a throat culture, courtesy of the U.S. National Library of Medicine:

• A throat culture is taken by using a long stick with cotton on the end to swab the throat and check for bacteria.
• Gagging is common during a throat culture, but try to resist the reflex.
• You shouldn't use an antiseptic mouthwash before the test.
• Side effects and pain are rare from a throat culture, but some people may feel nauseous, or may vomit or cough.
• The presence of abnormal bacteria on the culture indicates an infection, often strep throat.

The finding -- not yet replicated in people -- raises hope for developing a safer and more effective way to combat transmission of both diseases among humans.

"We're the first to show that you can use a sustained-release formulation of this antibiotic to completely inhibit both infections when transmitted simultaneously by ticks," said study author Dr. Nordin Zeidner, chief of the U.S. Centers for Disease Control and Prevention's Vector-Host Laboratory, in Fort Collins, Colo.

Zeidner stressed, however, that the treatment shouldn't be thought of as a vaccine for either disease but rather as a potentially novel method to inhibit infection following exposure.

"But this is, nevertheless, an important proof of concept," he added, "because we know that a lot of ticks infected with Lyme disease also carry this co-infection."

The study was published in the April issue of the Journal of Medical Microbiology.

Lyme disease is the most common tick-borne illness in the United States, with approximately 20,000 new cases diagnosed in 2006, according to the CDC. It's transmitted by blacklegged ticks infected with the bacterium Borrelia burgdorferi. The ticks are common in the upper Midwest and Northeastern regions of the United States and can also carry other diseases such as human granulocytic anaplasmosis, posing a risk for combined infections.

People infected with Lyme disease can experience flu-like fever, weakness, headache, fatigue, and skin rashes. If left untreated, the disease can spread to the joints, as well as to the heart and the nervous system. Symptoms of anaplasmosis can include fever, headache, lethargy, rashes and gastrointestinal problems, according to the CDC.

Efforts to develop a vaccine for either Lyme disease or anaplasmosis haven't met with much success. So, doctors stress prevention measures when outdoors, such as the use of insect repellants with DEET and covering up with clothing.

As for treatment, the CDC suggests that two to four weeks of repeated oral antibiotics -- such as doxycyline, amoxicillin, and cefuroxime axetil -- can effectively treat most patients, particularly when the infection is caught early.

But, some doctors and patient-advocacy groups have argued that chronic infections may require a much longer antibiotic regimen -- despite treatment guidelines issued in 2006 by the Infectious Disease Society of America that warned that long-term antibiotic use raises the risk for drug resistance and medical complications.

Searching for a way to address such concerns, Zeidner and his colleagues focused on the potential benefits of a single dose sustained-release version of the antibiotic doxycycline. They noted that a standard single oral dose of the drug is quickly cleared from the body (about eight hours) -- requiring continuous and repeated use. By contrast, the sustained-release version is injected and continues to circulate for approximately 19 days after delivery.

In their mice study, the researchers exposed 6-week-old female mice to ticks infected with both Lyme disease and anaplasmosis. Three days after infection, some mice were randomly assigned to receive a single dose of either oral or sustained-release injected doxycycline, while others were given just water or a non-antibiotic compound.

The results: 100 percent of the mice injected with the long-acting antibiotic were fully protected from developing either disease. Only 20 percent to 30 percent of the mice given the oral antibiotic were similarly protected, the researchers said.

"I want to emphasize, however, that this is an animal model of disease we're looking at, and this formulation is not ready to put in people tomorrow," Zeidner cautioned. "It will take some time before it's ready for the clinic."

Dr. Raphael B. Stricker, recent past president of the International Lyme and Associated Diseases Society, described the new research as "outstanding."

"This work is very interesting," he said, "because they've found a way to target both Lyme disease and another very significant disease that up until just four years ago wasn't even recognized. And since the current treatment could involve taking antibiotics for months at a time, a single shot like this -- giving long-term protection and maybe even treatment -- could certainly end up being preferable."

More information

For more on treating Lyme disease, visit the CDC.

The study, published in the February issue of the Annals of Neurology, followed 2,267 men who received olfactory testing at the Kuakini Medical Center in Honolulu at least once during two periods in the 1990s. They were followed for up to eight years and, during that time, 35 of the men developed the disease.

An odor identification problem preceded the development of Parkinson's by at least four years in these men. Decreased odor identification was associated with older age, smoking, more coffee consumption, less frequent bowel movements, lower cognitive function and excessive daytime sleepiness, but even after adjusting for these factors, those with the lowest odor identification scores had a five times greater risk of developing Parkinson's than those with the highest scores.

The results strengthen findings from earlier studies that suggest olfactory impairment begins between two and seven years before diagnosis.

Why problems with smelling accompany Parkinson's is not completely understood; however, nerve loss and the formation of Lewy bodies -- abnormal clumps of proteins inside nerve cells that are thought to be a marker of the disease -- are known to take place in the olfactory structures of patients with the disease.

The study authors noted that one previous study involving brain dissection of deceased patients with neurological disease found that olfactory structures are the earliest brain regions affected by Lewy degeneration, which supports the idea that an impaired sense of smell could be one of the earliest signs of Parkinson's disease.

An impaired sense of smell could also be caused by impaired sniffing, which may be another motor symptom of Parkinson's.

Olfactory testing, along with screening for other potential early indicators of Parkinson's disease such as constipation or sleep disturbances, could provide a simple and relatively economic means of identifying individuals at high risk who could participate in trials of medications designed to prevent or slow disease progression, the authors concluded in a prepared statement.

More information

The National Institute of Neurological Disorders and Stroke has more about Parkinson's disease.