Findings

Hustling up the escalator, I didn't have time to appreciate the irony of my situation: I was running late to a session on stress. It was with more than strictly professional interest then, that I settled in to hear 5 researchers discuss their latest findings on stress and the brain.

In some ways, stress is all in our heads, said Bruce McEwen, a neuroendocrinologist at Rockefeller University in New York City, since our brains are responsible for recognizing and responding to stressors. Three sections in particular: the amygdale, the hippocampus, and the prefrontal cortex work with the hypothalamus to flip on (and hopefully shut down) production of stress hormones and other automatic responses to stress, like increased heart rate. But researchers are now learning how stressors can physically alter our brains, which in turn, may impact how we learn, form memories, and even make decisions. The effects are sometimes reversible but sometimes not, the scientists reported.

Among the findings:

Stress the monkey. Simona Spinelli of the National Institutes of Health in Bethesda, Maryland and colleagues placed 13 young monkeys in the care of their peers for 6 months, while another 15 monkeys spent the same time with their mothers. Both sets of monkeys then rejoined typical social groups, and the researchers scanned their brains after several months of exposure to the normal environment. The monkeys raised under Lord of the Flies-like conditions showed enlarged brain regions in areas related to stress, compared to the control group, even after spending time in the normal environment. This suggests that early stress can have long-lasting impacts on the brain, Spinelli says, though follow-up studies in humans are necessary.

Studies show that chewing gum can affect mood and cognition, but can it improve memory? Researchers from Northwestern University in Evanston, Illinois, with the support of the Chicago-based Wrigley Science Institute, say that it can.

In a poster presented here today, team member and self-reported gum chewer Xue Wang, laid out the case. Ten healthy subjects performed short-term memory tasks, like trying to identify letters that repeated themselves among a series of letters, while intermittently solving math problems. The researchers ramped up the volunteers' stress levels (as measured via a skin conductor, which operates like a lie detector) by telling the subjects when they got a math answer wrong and pushing them to solve the problems faster.

Gum kept the volunteers sharp. When they chewed, activity increased in the parts of their brains associated with short-term memory—and indeed, they performed better on the memory tests. Their stress levels also went down: Subjects who didn't chew gum were 240% more stressed than baseline; those who did were only 50% more stressd. "It's unbelievable that chewing gum can do so much," says Wang.

Still, not everyone is ready to bite. Hector Vargas-Perez, a drug addiction researcher at the University of Toronto who visited the poster, says it's difficult to know what accounted for the gum's effect. "There are a bunch of variables that are involved: the sugar, the flavor, the mechanical part." Vargas-Perez said that he doesn't chew gum on a regular basis--and that the findings aren't quite enough to convince him to take up the habit.

--Haley Stephenson

Putting on one of the largest scientific meetings in the world is no trivial feat. It occupies the society's staff for most of the year. Thanks to SfN's Debra Speert for rounding up the numbers that illustrate some of the logistical challenges:

Attendance (as of noon Nov 18)
31,640 total attendance
9,016 international attendees
73 countries represented
577 exhibiting organizations

The poster floor
15,555 abstracts
110,000 push pins are ordered for the poster sessions--enough to fill a 55 gallon drum.

Mass Transit (as of noon Nov 17)
14,100 miles: Distance traveled by shuttle buses between hotels and the convention center.  This is more than the round-trip distance between DC and Tianjin, China.

Catering (as of noon Nov. 17)
400 Dozen Cookies Baked
335 Dozen Muffins Baked
2515 Gallons of Coffee Brewed
1 Ton of Fruit Cubed
2750 potatoes turned into fries

--Greg Miller

A Harvard researcher has managed to thoroughly confuse a mouse's sexual identity merely by monkeying with its odor-detecting brain circuits.
          
Mice have two types of olfactory systems, which are located in the nose with projections to the brain: the main one (MOE for main olfactory epithelium) for routine smelling such as food detection, and a second one called the veromonasal system (right and left, respectively in pic). That's the one that picks up on pheromones, the smells of love.            

Harvard biologist Catherine Dulac and colleagues wanted to see what would happen if they disrupted these systems. In one set of experiments, the team removed the veromonasal organ (VNO), either via genetic manipulation or destructive virus. The change essentially turned the males bisexual--they mated normally with females but also tried to have sex with males. But if their MOE systems were disabled instead, they lost interest in normal mating with females.             

  The Dialogues between Neuroscience and Society lecture series has become a popular feature at the society's annual meeting that brings neuroscientists together with leaders in other fields to look for common ground. This year's lecture, for example, featured dance choreographer Mark Morris. Yesterday I asked incoming society president Thomas Carew what's on tap for the 2009 meeting in Chicago. A bit of magic is what.

Next year's attendees will hear from James Randi (aka The Amazing Randi) and Apollo Robbins. "For centuries magicians have been practicing their craft based on the way we perceive and encode information about the world," said Carew. Their tricks have a lot to teach neuroscientists about perception, awareness and attention, he said. At the same time, neuroscientists may be able to help magicians understand why the tricks they've discovered and perfected by trial and error fool the brain so effectively.

It sounds like an interesting dialogue, and it's one that has already started. Randi and Robbins are co-authors on a paper in this month's Nature Reviews Neuroscience urging neuroscientists to adopt "magical methods"--such as what happens in the brain when perceptions don't match reality.

--Greg Miller

Epigenetics has been a hot topic at this year's meeting. When I ducked out of a symposium devoted to it on Saturday afternoon to catch another talk, by the time I got back the room was jam packed and a convention center employee was turning people away. "If the fire marshal comes we'll be in big trouble," she said.

There was only slightly more elbow room at this afternoon's press conference, where half a dozen researchers described their recent work investigating the possible roles of epigenetic mechanisms in everything from learning and memory to problems such as obesity, drug addiction and anxiety.

In a nutshell, epigenetics means altering gene expression without messing with DNA sequences. It includes DNA methylation, a chemical alteration to DNA that prevents genes from being read out to make proteins, and histone deacetylation, which accomplishes the same thing by keeping DNA strands tightly wound around spool-like histone proteins. Epigenetics has been a growing area of exploration  in cancer biology over the last 20 years. Drugs that inhibit histone deacetylation, for example, have shown promise as cancer-fighting drugs. 

Relatively little is known about the role of epigenetic mechanisms in the brain, but researchers described several intriguing findings at the press conference. Among them:

They say "romantic love" was invented by the troubadors of the Middle Ages. They also say it doesn't last. But Rutgers University anthropologist Helen Fisher and colleagues reported today that functional brain imaging studies show that being "in love" transcends both culture and time.

The researchers imaged the brains of 17 young Americans and 17 young Chinese who had been in intense love relationships for 6 months. The team compared how the volunteers' brains reacted to a photograph of a loved one versus a photo of someone they didn't know. When viewing a loved one, the brains of the volunteers registered activity in "several regions associated with addiction," said Fisher--notably in the ventral tegmental area, a region of the brain stem that are rich in receptors for dopamine, the chief actor in the brain's "reward circuit".

As I was checking email in the press room today I noticed Thomas Insel, the director of the National Institute of Mental Health, come in and take a seat at a nearby table. He'd arrived a few minutes early for a press conference at which several National Institutes of Health (NIH) officials were to sing the praises of NIH-funded research being presented at the meeting. At the suggestion of a colleague, I took the opportunity to ask him about the allegations of financial conflicts of interest leveled at several prominent academic psychiatrists in recent months.

The allegations arise from an investigation led by Senator Charles Grassley (R-IA) that has uncovered evidence that several high-profile researchers violated ethics rules by failing to report hundreds of thousands of dollars in consulting income from pharmaceutical companies. In one case, NIH suspended a grant to a psychiatrist, Charles Nemeroff of Emory University in Atlanta, who allegedly reported only $1.2 million of at least $2.4 million he received from device and drug companies between 2000 and 2007.

Some tastes--like blue cheese or green olives--are "acquired." But can we conquer our aversion to a food before we even taste it for the first time? Neuroscientist Donald Katz at Brandeis University has shown that it can happen with rats.

Rats like sweet tastes best of all. They also like salt. They dislike sour, and they hate bitter. Armed with this knowledge, Katz and colleagues decided to see if they could get the creatures to change their minds about bitter cocoa if they met a pal who seemed to like the stuff.

First the researchers got a rat hungry enough that it would be willing to nibble at some raw cocoa. Then they put another rat in with it so rat number 2 could smell the first rat's breath. Finally, the researchers placed the second rat in a cage with two unfamiliar and not particularly appetizing dishes to choose from. Despite their innate aversion to bitter taste, the rats went for the cocoa.

Even male zebrafinches need a bit of inspiration to do their best work. In her lecture here Saturday night, University of California, San Francisco neuroscientist Allison Doupe described how male finches tighten up their performance when a female is in view. With no one around, a male zebrafinch is liable to botch a few notes in his well-practiced song: sometimes he's a little flat, sometimes a little sharp. But with a fine-feathered female listening from a neighboring cage, he's more likely to hit all the right notes. Doupe's lab has been investigating the underlying neurophysiology, and she thinks this line of study may ultimately help clarify the function of the basal ganglia--a part of the brain that's crucial for learning skilled movements and one that's affected by several neuropsychiatric disorders.

In one experiment, Mimi Kao in Doupe's lab used microelectrodes to record the activity of neurons in a brain region called LMAN, a component of the avian basal ganglia. When a male finch sang to a female, LMAN neurons fired in a predictable pattern, with individual neurons firing when he sang a particular element of the song.  But when the same male sang on his own, the pattern deteriorated and became less precise--much like his song.