Research round up: Sleep, reward-based learning, networking

Tiredness, rewards, status: it's all in the head, three research studies say.

A way to cheat sleep?

Michael Halassa, a doctoral student in the School of Medicine, and Philip Haydon, Halassa's former mentor and a professor at Tufts University, collaborated to study astrocyte cells in the brain and their impact on animal sleep behavior.

Among the functions of astrocytes are providing nutrients to nervous tissue and repairing the brain after traumatic injuries.

"Most of the past century, [astrocytes] have been ignored," said Halassa.

For 15 years, researchers have known that astrocyte cells release chemicals, such as adenosine, which causes the need to sleep. Although this suggests that astrocytes might control sleep, there was no behavioral data to support the idea. Halassa studied genetically modified mice whose astrocytes did not release adenosine.

Halassa and Haydon, along with a team of researchers, found that with this absence, sleep-deprived mice were able to function just as well as if they had not been.

The "most important discovery," said Halassa, was that the mice's short-term memory was completely intact even after little sleep.

"Now the idea is to target the pathway by a drug," Halassa said. However, students studying for the MCATs should not rejoice too soon, because "we still don't know what would happen if we blocked it for a long period of time."

Rewards good for brain

Kareem Zaghloul, a post-doctoral fellow in neurosurgery, and his team of neuroscientists and psychologists studied the correlation between unexpected rewards and neuronal activities in the substantia nigra, a brain structure that controls reward-based learning.

The researchers implanted electrodes in the brains of patients with Parkinson's disease, kept them awake and allowed them to play a card game on the computer. If they picked the right card, they were rewarded unexpectedly, and neural activity increased.

His findings could potentially aid clinical treatments, but it's too early to tell, Zaghloul said.

Producing a 'buzz'

In today's economy, pharmaceutical companies look to market products in a "smarter way," Wharton marketing professor Christophe Van den Bulte said.

He and fellow Wharton marketing professor Raghuram Iyengar studied the product "buzz" phenomenon's correlation to networking in the world of pharmacists and physicians.

Working with consulting company Rivermark, they surveyed physicians about their social networks and their perceptions about their own importance in the community.

They then assessed each person's sociometric importance - how important others consider them - their self importance and how each would affect product marketing.

They found that the correlation between sociometric and self-importance was very low. They also found that both sociometric and self-important leaders are quicker to promote new drugs than those that are not leaders, but that sociometric leaders adopt even faster.

They also found that a product's "buzz" was present even after removing marketing factors.

Lastly, sociometric leaders - "true" leaders" - listen to what other people say and do.

All four results show that in a matter of "real status versus ego," real status matters much more for marketers, Van den Bulte explained.

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