Breaking News
October 20, 2018 - Pounds Regained After Weight-Loss Op Can Tell Your Doc a Lot
October 20, 2018 - Sending parents letters to fight childhood obesity doesn’t work
October 20, 2018 - Supervised aerobic exercise can support major depression treatment
October 20, 2018 - Mindfulness-based program effective for reducing stress in infertile women
October 20, 2018 - Molecule capable of halting and reverting neurodegeneration caused by Parkinson’s disease identified
October 20, 2018 - Midazolam-mediated alterations of PER2 expression may have functional consequences during myocardial ischemia
October 20, 2018 - Sweat bees are ideal for studying the genes underlying social behavior
October 20, 2018 - Weight loss success associated with brain areas involved in self-control
October 20, 2018 - KHN’s ‘What the Health?’ Republicans’ preexisting political problem
October 20, 2018 - Research provides a more complete picture of suffering caused by terrorist attacks
October 20, 2018 - Eradicating Helicobacter pylori infections may be a key treatment for Parkinson’s disease
October 20, 2018 - Breast Cancer as a Dynamic Disease
October 20, 2018 - University of Pittsburgh wins NSF grant for big data research to prevent complications from anesthesia
October 20, 2018 - Skin-to-skin contact may promote attachment between parents and preterm infants
October 20, 2018 - Recommendations Developed to Verify NGT Placement in Children
October 20, 2018 - Weight loss can be boosted fivefold thanks to novel mental imagery technique
October 20, 2018 - Children with autism are more likely to be overweight, obese
October 20, 2018 - Nurses making conscientious objections to ethically-relevant policies lack support
October 20, 2018 - Prion strain diversity may be greater than previously thought
October 20, 2018 - Antidepressant treatment may lead to improvements in sleep quality of patients with depression
October 20, 2018 - Study reports increased risk of death in children with inflammatory bowel disease
October 20, 2018 - Number of Autism Genes Now Tops 100
October 20, 2018 - Total diet replacement programmes are effective for treating obesity
October 20, 2018 - CLARIOstar used for fluorescence measurements on CSIRO’s purpose-built research vessel
October 20, 2018 - People with more copies of AMY1 gene digest starchy carbohydrates faster
October 20, 2018 - Case Comprehensive Cancer Center wins NIH grant to study health disparities
October 20, 2018 - Newly discovered compound shows potential for treating Parkinson’s disease
October 20, 2018 - High rate of non-adherence to hormonal therapy found among premenopausal early breast cancer patients
October 20, 2018 - Immunotherapy medicine found to be effective in treating uveitis
October 20, 2018 - The Pistoia Alliance Calls for Greater Collaboration to Realise Benefits of Innovation and Announces Winners of the 2018 President’s Startup Challenge
October 20, 2018 - Female internists consistently earn less than men
October 20, 2018 - Stanford team looks at dangers of teens’ vaping habits
October 20, 2018 - New approach to understanding cancers will accelerate development of better treatments
October 20, 2018 - LJI and UC San Diego awarded $ 4.5 million as part of NCI’s Cancer Moonshot initiative
October 20, 2018 - School-based HPV vaccination did not increase risky sexual behaviors among adolescent girls
October 20, 2018 - Eye discovery to pave way for more successful corneal transplants
October 20, 2018 - New analysis examines the importance of location in the opioid crisis
October 20, 2018 - Green filters increase reading speed for children with dyslexia
October 19, 2018 - Bariatric Sx Cuts Macrovascular Complications in Obesity, T2DM
October 19, 2018 - Better assessments for early age-related macular degeneration
October 19, 2018 - Visible and valued: Stanford Medicine’s first-ever LGBTQ+ Forum | News Center
October 19, 2018 - Understanding of metal-free enzymes used by bacteria could lead to new effective antibiotics
October 19, 2018 - Beckman Coulter Life Sciences announces new research-focused website
October 19, 2018 - Study finds link between refined soluble fibers, gut microbiota and liver cancer
October 19, 2018 - Social media reduces risk of depression among seniors with pain
October 19, 2018 - Newly developed synthetic DNA molecule may one day be used as ‘vaccine’ for prostate cancer
October 19, 2018 - Preoperative weight loss may not provide health benefits after surgery
October 19, 2018 - U.S. Birth Rates Continue to Drop as Age of New Moms Rises
October 19, 2018 - New technology can keep an eye on babies’ movements in the womb
October 19, 2018 - Juul e-cigarettes pose addiction risk for young users | News Center
October 19, 2018 - Gene sequencing reveals crucial molecular aspects of Trypanosoma brucei
October 19, 2018 - New DNA vaccine strategy protects mice against lethal challenge by multiple H3N2 viruses
October 19, 2018 - Study shows close link between cytokine interleukin-1ß and obesity-promoted colon cancer
October 19, 2018 - Muscle mass plays a critical role in health, shows research
October 19, 2018 - Study finds undiagnosed prediabetes in many infertile men
October 19, 2018 - The Current issue of “The view from here” is concerned with Nanotherapeutic strategies
October 19, 2018 - Delay in replacing the Pap smear with HPV screening is costing lives
October 19, 2018 - Physicians battle pediatric diseases of ear, nose, throat in Zimbabwe | News Center
October 19, 2018 - Researchers investigate why some cancers affect only young women
October 19, 2018 - Drugmakers funnel millions to lawmakers; a few dozen get $100,000-plus
October 19, 2018 - Unselfish people tend to have more children and receive higher salaries
October 19, 2018 - New findings reveal potential cellular players in tumor microenvironment
October 19, 2018 - Study reveals impact of Juul use on teenagers and young adults
October 19, 2018 - Green leafy vegetables could help reduce macular degeneration risk
October 19, 2018 - Some countries take more time for reimbursement decisions on new cancer drugs
October 19, 2018 - Human brain cell transplant offers insights into neurological conditions
October 19, 2018 - Parental education associated with increased family health care spending
October 19, 2018 - New statistical method estimates long- and short-term risk of recurrence of breast cancer in US women
October 19, 2018 - Father’s exposure to nicotine may cause cognitive deficits in descendants
October 19, 2018 - Could we prevent Alzheimer’s disease by treating herpes?
October 19, 2018 - Nurse-led care can be more successful in managing gout
October 19, 2018 - Trump administration, pharma exchange verbal volleys on drug-price transparency
October 19, 2018 - Duke researchers find way to detect blood doping in athletes
October 19, 2018 - Many primary care doctors are still prescribing sedative drugs for older adults
October 19, 2018 - Finger length can predict sexuality in women say researchers
October 19, 2018 - Study finds differences in side-effects experienced by male and female OG cancer patients
October 19, 2018 - Dysfunction of single gene leads to miscarriages
October 19, 2018 - Few Seniors Who Self-Harm Referred for Mental Health Care
October 19, 2018 - Don’t sweat the sweet stuff
October 19, 2018 - URMC researchers discover new approach to deliver therapeutics to the brain
Researchers discover specific taste neurons necessary for protein craving in fruit flies

Researchers discover specific taste neurons necessary for protein craving in fruit flies

image_pdfDownload PDFimage_print

A team of neuroscientists from the Champalimaud Centre for the Unknown (CCU), in Lisbon, Portugal, has discovered that were it not for specific taste neurons located in the fruit fly’s proboscis (the equivalent of our tongue), the fly would not develop a craving for protein even when in excruciating need of it. The results, published in the journal eLife, could represent a step towards preventing the transmission of certain insect-borne human diseases.

The team had already shown that flies can develop a craving for proteins when they are deprived of essential amino-acids, that is, when they lack the protein building-blocks that their organism is unable to synthesize. But the neuronal mechanisms involved were not known.

In the new study, led by Carlos Ribeiro and whose first authors are Kathrin Steck and Samuel Walker, the scientists now show that this involves changes in the taste system – and identify two groups of neurons that are necessary for this protein craving.

The team set out to search for the sensory neurons that accounted for the appetite that flies develop for yeast when they are amino-acid deprived. Yeast is the main natural protein source for fruit flies, and flies eat protein when lacking essential amino-acids.

“The first step was to systematically silence different neurons in the fly to look for the ones which, when turned off, eliminated the protein-deprived fly’s appetite for yeast”, explains Ribeiro.

Indeed, the authors found that silencing specific taste neurons inhibited flies’ appetite for yeast. This was true even when protein needs were at their highest: the females used in this part of the study were mated, and therefore had a large demand for protein for the production of eggs.

Actually, the scientists identified two different sets of taste neurons involved in the insects’ yeast appetite: one on the outside of the proboscis and one on its inner surface.

They then confirmed the role of the identified taste neurons by recording their activity when they were fully functional. “We showed that in the amino-acid-deprived fly, if you put yeast on their tongue, you see a specific reaction to yeast in those taste neurons”, says Ribeiro.

“We were surprised to see that the response of those taste neurons to yeast was increased after flies were fed on a diet lacking amino acids”, notes Ribeiro. The team was not expecting that such a change in response to the same taste, depending on the fly’s hunger, could happen at such an early stage in sensory processing, that is, right at the tip of the tongue. “The neurons became very sensitive to yeast and they fired very strongly” in the presence of yeast.

According to Ribeiro, this means that these specific proboscis neurons make yeast taste much better to the animals lacking amino-acids, thus accounting for their yeast craving. “These neurons change the way the fruit fly sees the world”, he notes.

Besides amino-acid status, flies’ craving for protein is influenced by another important internal state: their mating state. This is because after flies mate, they start producing eggs, and this egg production absolutely depends on ingestion of protein. “Pregnant female flies eat much more protein than virgin females because they need to make eggs”, says Ribeiro.

Surprisingly, though, the team found no effect of the reproductive state of the fly on the taste neurons’ activity, whether they were amino-acid satiated or deprived . “This is one of the first studies”, says Ribeiro, “to show that mating changes the way the fly tastes the world at a different level of the brain”, and not at the level of the tongue. A result, he adds, that “is very important for neuroscience”, insomuch as many different internal states affect behavior but it is not known precisely how the signals from each of them are integrated by the brain to produce a particular behavior.

Eat and keep on eating

But there’s more. The team further showed that each of the two sets of neurons regulated a different part of the insects’ feeding behavior. This novel result, says Ribeiro, was possible only with the “flyPAD”, a technology that had been developed by the laboratory at the CCU. “The flyPAD allows us to see very precisely how the animal eats”, he explains. “It uses touch-screen technology like that in your iPad or iPhone”.

More specifically, the scientists discovered that the taste neurons on the outside of the proboscis were responsible for the initiation of the feeding behavior, while the ones on the inside sustained the feeding behavior. “The first set makes the fly start to eat yeast, telling it it is the right food, and the second set tells it to keep on eating it, that yeast is still the right food”, Ribeiro summarizes.

If similar taste neurons were also at play in the mosquito’s protein craving, this could have implications in terms of controlling malaria and other mosquito-borne diseases. For the most part, mosquitoes live on nectar: only females sting animals and humans because they absolutely need protein from their blood to lay eggs.

“If mosquitoes have similar taste neurons as flies, a chemical which would block those taste neurons in female mosquitoes could cancel this craving”, says Ribeiro, thus preventing the transmission of the malaria parasite from insect to person. “This would be an interesting contribution to stopping the spread of many deadly diseases.”

Source:

http://www.fchampalimaud.org/

Tagged with:

About author

Related Articles