Brain's on-off thirst switch identified

January 27, 2015

Brains on-off

Washington, Jan 27: Scientists have identified neurons that trigger our sense of thirst and those that turn it off.

For years, researchers have suspected that thirst is regulated by neurons in the subfornical organ (SFO), in the hypothalamus. But it has been difficult to pinpoint exactly which neurons are involved.

“When researchers used electrical current to stimulate different parts of the SFO of mice, they got confusing results,” said lead author Yuki Oka, a postdoctoral research scientist in the laboratory of Charles S Zuker, a Howard Hughes Medical Institute Investigator at Columbia University Medical Center (CUMC).

The CUMC team hypothesised that there are at least two types of neurons in the SFO, including ones that drive thirst and others that suppress it.

“Those electrostimulation experiments were probably activating both types of neurons at once, so they were bound to get conflicting results,” said Oka.

To test their hypothesis, Oka and Zuker turned to optogenetics, a more precise technique for controlling brain activity. With optogenetics, researchers can control specific sets of neurons in the brain after inserting light-activated molecules into them.

Shining light onto these molecules turns on the neurons without affecting other types of neurons nearby.

These “mind-control” experiments revealed two types of neurons in the SFO that control thirst: CAMKII neurons, which turn thirst on, and VGAT neurons, which turn it off.

When the researchers turned on CAMK11 neurons, mice immediately began to seek water and to drink intensively.

This behaviour was as strong in well-hydrated mice as in dehydrated ones. Once the neurons were shut off – by turning off the light – the mice immediately stopped drinking.

The researchers also found that light-stimulation of the CAMKII neurons did not induce feeding behaviour. In addition, light-induced thirst was specific for water and did not increase the animals’ consumption of other fluids, including glycerol and honey.

Similar experiments with VGAT neurons showed that these neurons act to turn off thirst. When the researchers turned on these neurons with light, dehydrated mice immediately stopped drinking, even if they were drinking water.

“Together, these findings show that the SFO is a dedicated brain system for thirst,” said Oka.

“The SFO is one of few neurological structures that is not blocked by the blood-brain barrier – it’s completely exposed to the general circulation,” said Oka.

“This raises the possibility that it may be possible to develop drugs for conditions related to thirst,” Oka added.

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Agencies
April 28,2020

As the world grapples with the impact of the novel coronavirus, daily interaction with the outside world --- public and retail spaces, restaurants, educational institutions, and even with each other has been and will continue to be reoriented prioritising personal hygiene and public health.

The sensibilities are building towards and leading to major changes in how the country's food service industry is expected to operate.

Based on a recent consumer survey by restaurant tech platform, Dineout, Indian diners are now ranking safety assurances and premier hygiene as top factors when it comes to choosing a restaurant to dine in.

The survey by Dineout conducted across 20 cities revealed that in a post-COVID-19 era, 81 per cent diners will prefer digital menus at restaurants, while 77 per cent of people will continue to want to dine out.

The survey found that 23 per cent people would prefer continuing with delivery/takeaway and online payment becomes the most preferred option with 60 per cent votes.
 
Diner's response to Contactless Dining:

 

Over 96 per cent demand better waitlist management
 
81 per cent consumers would rather scan a QR on their phone to place an order instead of handling physical menus or tablet-based digital menus.
 
After a dining experience, 60 per cent prefer seamless wallet-based digital payments over cash/cards 85 per cent would choose a digital valet over waiting in possibly contaminated public spaces and 84 per cent would prefer offering digital feedback over physical feedback collection.

 

What do people want to eat?
 
The report also revealed that most of India has been craving Pizza since the lockdown, except in Chennai, Hyderabad and Kolkata where their popular and indigenous Biryani recipes reign supreme. 
 
Which restaurants are diners waiting to go to?
 
77 per cent respondents claimed that they are waiting to dine out with friends and family once the lockdown is lifted.
 
Big Chill, Barbeque Nation and Social emerged as favourites in Delhi, while Mumbaikars picked Global Fusion, Poptates and Asia Kitchen. Bangaloreans miss going to pubs like Toit, Vapour and Barbeque Nation.
 
Aminia, Arsalan and Momo I Am emerge as the top picks in Kolkata.
 
Contrary to popular belief, Delhitties picked vegetarian over non-vegetarian food.
 
Bangaloreans and Lucknowis would rather have their drinks over food.
 
Besides the new parameters for restaurant selection, the factors deciding consumer delight have also seen a major overhaul as hygiene takes precedence. Consumers would prefer that the total number of reservations in a certain period be limited with the option to pre-select the seating, ample amounts of sanitisers at tables along with UV sanitised utensils whenever possible.
 
Hygiene ratings with detailed hygiene information, regular hygiene checks & usage of mask and disposable gloves by waiters are likely to be the new standard, with diners expecting service personnel to sanitise tables & chairs after every use.
 
Dineout recently unveiled the �contactless dining suite' to help restaurants survive and thrive in a post-COVID-19 world. The brand will also provide PPE Safety Kits to Restaurants to help ensure hygiene measures and is facilitating COVID free certification for restaurants through a licensed lab to ensure all microbiological tests are in place before restaurants restart post the lockdown.

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Agencies
July 2,2020

London, Jul 2: The World Health Organisation says smoking is linked to a higher risk of severe illness and death from the coronavirus in hospitalised patients, although it was unable to specify exactly how much greater those risks might be.

In a scientific brief published this week, the U.N. health agency reviewed 34 published studies on the association between smoking and Covid-19, including the probability of infection, hospitalisation, severity of disease and death.

WHO noted that smokers represent up to 18% of hospitalised coronavirus patients and that there appeared to be a significant link between whether or not patients smoked and the severity of disease they suffered, the type of hospital interventions required and patients' risk of dying.

In April, French researchers released a small study suggesting smokers were at less risk of catching Covid-19 and planned to test nicotine patches on patients and health workers — but their findings were questioned by many scientists at the time who cited the lack of definitive data.

WHO says "the available evidence suggests that smoking is associated with increased severity of disease and death in hospitalized Covid-19 patients. It recommends that smokers quit.

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Agencies
April 15,2020

Dear parents, if you want your children to have proper sleep, read this carefully. Joining a growing list of studies that tell parents to shun devices at bed-time, researchers say that children who use devices and decide what time they go to sleep, achieve less sleep and feel more sleepier the following day than their peers.

The study of children in this age-group (aged 11 to 13 years), published in the New Zealand Medical Journal, found most (72 per cent) of the 163 students interviewed by University of Otago researchers achieved recommended guidelines of an average 9 to 11 hours sleep nightly over one week.

"But that also means that almost one in four students did not achieve sleep within these guidelines, which highlights an area for improvement," said study researcher Kate Ford.

However, consistent with previous research in 15 to 17-year-old New Zealanders, the study results show less sleep on the nights where devices are used in the hour before bed.

According to the researchers, students who used devices before going to sleep were also more likely to report that they felt sleepy the following morning. Watching television before bed had no significant effect on sleep length.

There were also some interesting observations over the weekends where students went to bed later but woke later achieving similar sleep length to the school days, the researchers said.

A small group of students (six per cent) who reported less than seven hours of sleep, including a small number reporting not sleeping at all, according to the study,

Therefore, while the average across the week of 72 per cent of students reporting adequate sleep is reassuring, it is far from the goal of every child achieving sleep within the recommended guidelines," Ford said.

Dr Paul Kelly, head of the Sleep Health Service at Canterbury District Health Board, supervised the study and explained that the foundations for good health are based on proper nutrition, regular exercise and good sleep quality.

Sleep quality is often overlooked as a contributory factor to poor health.

"The study findings suggest the need for parental guidance around bedtimings and moderation of the use and availability of electronic devices before bed," Kelly said.

"Respect and protect your sleep, as good daytime functioning is reliant on adequate sleep," Kelly added.

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