More MS news articles for Nov 2001

New windows into the brain

21 November 2001
by Apoorva Mandavilli

The Society for Neuroscience annual meeting "is a zoo," one neuroscientist put it, some weeks before this year's conference: "Everyone hates it, yet everyone goes."

This year was no different: Undaunted by slashed budgets or security concerns, a record 28,500 attendees from all over the world swarmed in on sunny San Diego.

Armed with massive programs, neuroscientists could be seen and heard everywhere: in hotels, restaurants, on TV, in taxicabs, jogging on the boardwalk. For the week of the conference, the town normally known for such intellectual exclamations as "dude" and "sweet!" resounded with animated debates on neuronal plasticity, synapses and signaling.

For some young scientists, the main attraction was the opportunity to see neuroscience greats and Nobelists like Eric Kandel, Stanley Prusiner and Paul Greengard. In a Presidential Special Lecture Paul Greengard told a packed conference hall that the latest studies of the dopamine receptor, implicated in disorders from Parkinson's disease to schizophrenia, all converge on DARPP-32, a molecule he predicts will make pharmaceutical companies very happy.

Stem cells, which dominated last year's program, again made for memorable news. Glial cells, which most neuroscientists have regarded as support cells, can in fact serve as stem cells that generate neurons even in adults, Magdalena Götz and her colleagues at the Max-Plank Institute of Neurobiology reported. Harvard neurologist Evan Snyder proposed that transplanted neural stem cells can alleviate neural degeneration by instructing host cells to regenerate, rather than by maturing into neurons themselves.

One of the most intriguing studies of the conference came from Arthur Craig of the Barrow Neurological Institute in Phoenix, Arizona. Craig presented classic anatomical tracings, as well as cutting-edge PET and fMRI scans, that delineate the insular cortex, a unique region he says registers the inner state of the body and generates the uniquely human sense of self.

Using such fancy imaging techniques to reveal the workings of the brain was a common thread in this year's sessions. Electron microscopy is poised to unravel the mysterious structures within the nerve synapse, revealed Uel (Jack) McMahan, a professor of neurobiology at Stanford University School of Medicine. Entire sessions were devoted to new techniques in diagnosing Alzheimer's disease (AD), the most promising of which is a derivative of the Congo Red probe that can penetrate the blood-brain barrier and selectively label plaques, tangles, and cerebrovascular amyloid.

University of Pennsylvania researchers identified regions of the brain that become metabolically active when a person lies, using used to identify event-related functional magnetic resonance imaging (fMRI); Canadian researchers unmasked the connections between speech and music, between listening and performing; and Emory University researchers pinpointed a region that helps us grasp mirror images and use them to direct our movement.

For the first time, researchers have also been able to predict a monkey's behavior solely on the basis of which neurons fire in a portion of its brain. Columbia University neurologist Michael Goldberg arrived at those results using a novel test to measure attention. SFN's president-elect Huda Akil is employing increasingly popular microarrays to identify genes that are important in emotional response. Cortical molecules of the stress system play a critical role in shaping individual differences in emotional reactivity, Akil said.

Several different teams also presented seemingly contradictory results on gender-specific differences in the response to stress. Columbia University neurobiologist Darcy Kelley says the South African clawed frog, Xenopus laevis may be a model system to study the cellular effects of hormones in generating gender-specific characteristics. Janis Weeks of the University of Oregon also showed precisely how steroid hormones affect individual neurons in the simple nervous system of a caterpillar.

As with other years, several sessions were devoted to individual disease studies. Two types of cell transplants were shown to hold off muscle atrophy in mouse models of amyotrophic lateral sclerosis (ALS). University of Pennsylvania researchers discovered that dendrites, the signal-receiving end of neurons, go awry to cause diseases such as Fragile X mental retardation. Scientists cautioned that the miracle drug L-dopa, which has been prescribed for Parkinson's disease (PD) patients for more than 30 years, may itself be partly responsible for the cognitive deficits associated with PD. Alzheimer's disease researchers dueled over the efficacy of the vaccine approach, now in clinical trials, in reversing cognitive deficits associated with that disease.

In normal aging brains, the prefrontal area of the brain takes the biggest hit, and people who age successfully compensate for the loss by engaging both hemispheres. In neurodegenerative diseases like AD and PD, some researchers argued, protein aggregates themselves may not directly damage the nerve cells, or produce the clinical signs. Rather, they suggest, dysfunction may be due to the toxic effects of soluble forms of the affected proteins.

In neuroscience, perhaps more than other life sciences, such disagreement is not uncommon. Synaptic research veteran Thomas Sudhof rued his role in the "in-fighting" of the synapse world, saying, "many times, scientists propose ideas not because they believe it's completely true but to be known for an idea. It would be better to concentrate on known facts." Dale Schenk, who took the contentious Alzheimer's field by storm two years ago, advised young scientists to just worry about the science. "You can't own science. It is what it is," he said. "Patients don't care who did what when. All they care about is a treatment. And we have to work as hard as we can do that."

SFN 2001
Society for Neuroscience

© Elsevier Science Limited 2000