Sick With the Flu? Scientists Find Throat Neurons That Detect Infection Signs, Alert the Brain

Scientists were able to pinpoint throat neurons that are capable of detecting infection signs and alerting the brain of the virus.

Sick With the Flu?

Flu can make even the toughest individuals stay in bed and lose appetite. Now, according to Nature, scientists have pinpointed mouse neurons that inform the brain of a flu infection. This also triggers a decline in hunger, thirst, and movement.

Stephen Liberles, who is the study's senior author, a professor of cell biology at the Harvard Medical School's Blavatnik Institute, and a Howard Hughes Medical Institute investigator, says that the study helps in understanding the detection mechanisms of pathogens and how these relate to the nervous system.

The findings of the study also offer insight regarding how anti-inflammatory and nonsteroidal medications, including aspirin and ibuprofen, may relieve flu symptoms.

Ishmail Abdus-Saboor, who is a sensory biologist from Columbia University at Ney Work and who did not participate in the study, mentions how these findings flip previous notions. The results serve as a paradigm shift in current notions regarding sickness behaviors.

If such results could be translated to a human context, findings could be vital when it comes to the advancement of flu treatments.

Throat Neurons That Detect Infection Signs

The team was directed by researchers from Harvard Medical School. As they studied the mice, the researchers found that specific throat neurons had pivotal roles in making the brain aware of a flu infection.

As part of the study's procedures, the researchers focused on another sickness controlled by the brain: sickness due to a respiratory infection.

Liberles explained that when an infection hits, the brain "orchestrates symptoms" while the body comes up with an immune response. Depending on the bug, these symptoms may include loss of appetite, lethargy, fever, coughing, vomiting, diarrhea, or congestion.

The team focused on influenza, a respiratory virus that makes millions of people sick and causes the deaths of thousands across the US.

Na-Ryum Bim, who is the study's first author and a HMS research fellow for the Liberles lab, pinpointed small neural populations that were embedded in the glossopharyngeal nerve. He discovered that such neurons are important for informing the brain of a flu infection.

The neurons also have lipid receptors known as prostaglandins. Both humans and mice make these lipids when an infection hits. Medications like aspirin and ibuprofen target them.

The researchers discovered that cutting the nerve, removing the neurons, blocking the receptors inside the neurons, or medicating the mice with ibuprofen all decreased the symptoms of influenza and boosted survival.

The findings altogether suggest that such throat neurons pick up the prostaglandins that build up when an infection hits. The neurons also become a communication channel that informs the brain.

Findings show how medications like aspirin and ibuprofen can help decrease symptoms of flu. They also suggest that such medications could increase survival.

Second Sickness Pathway

The researchers also found evidence of a second sickness pathway from the lungs to the brian. They observed that this pathway got activated as the virus went deeper into the body's respiratory system.

Surprisingly, prostaglandins are not involved in this second sickness pathway. Mice who were in this second infection phase did not react to ibuprofen treatments.

These findings propose an opportunity to boost treatments of flu if scientists can come up with new drugs that target this second sickness pathway.

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