Neuroscience is all about making connections, and at this year's meeting of the Society for Neuroscience in Orlando, the connections between genes, circuits, and behaviors or diseases - and the surprising plasticity of the adult brain - were major themes. "The brain is a very sophisticated organ for bringing together the inner and outer world," said Huda Akil, president-elect of the Society for Neuroscience. "Experience and genes meet in the brain because that is the point."

Neurons firing and synapses connecting, the nearly 22,000 scientists here at the Society for Neuroscience took in science and fun here in Orlando - poring through thousands of posters, attending hundreds of presentations, swimming, dancing, and eating at local establishments. Many came to network, and others to look for jobs.

The meeting is "so god-awful big," one European scientist told BioMedNet News that it's easier to find European researchers there than it is in Europe. "Everyone I want to talk to is here."

For the first time, researchers attending the conference didn't have to carry around a tome to keep track of their schedules. This year, the conference sponsors split the daily program into sections for each day and gave conference attendees a CD containing all the abstracts. Despite all the activities, the meeting's theme, "It's About the Science," reminded neuroscientists of the most important connection they share: A love for research.

If neuroscientists here at the meeting want excuses for not remembering all the information presented, some may be encouraged by findings from Michela Gallagher at Johns Hopkins University. Gallagher and her colleagues showed results suggesting that age-related memory losses are due to subtle functional changes in hippocampal neurons, rather than more overt damage to the cells. Further, differences in neurogenesis don't predict which rats develop age-related cognitive impairment, she reported. That implies therapies can be designed to boost neuron function - a sort of bifocal for the mind.

Memory and age-related cognitive decline are just the tip of the iceberg when it comes to linking genes and molecular mechanisms to behavior and disease. Fruit flies may give insights into the mechanisms of addiction, for example. Several researchers, including expert Barry Everitt, presented studies in rodents illuminating brain regions and molecules crucial in compulsive drug-seeking behavior, tendency to overeat. Studies in fruit flies are elucidating the molecules through which circadian clocks influence behavior - perhaps guests at the meeting will someday find ways to cram everything in without having to sleep.

Scientists have looked at the activity of hyperexcitable sodium channel genes in mice and are learning how these mutations might induce epilepsy. Behavior may also influence disorders. For example, an overly solicitous spouse can exacerbate chronic pain.

Parkinson's research is moving forward on many fronts, as reflected in the large number of presentations on this topic. Based on the success of deep brain stimulation, researchers are re-examining their ideas about what triggers the symptoms of the disease. Patients with Parkinson's have slow, rigid movements that were previously attributed to too-frequent firing of nerves in the basal ganglia. New results from the lab of Jerrold Vitek suggest that symptoms may actually be due to abnormal patterns of neuron activation. Anders Björklund of Lund University in Sweden reviewed the success of cell transplantation for Parkinson's and laid out future steps - such as standardizing procedures and assuring the quality of transplanted cells - needed to move ahead with cell-based therapies. Stem cell transplants may help patients with spinal cord injuries.

While Alzheimer's has long been linked to abnormal plaques in the brain, researchers at the meeting presented work getting at the mechanisms through which abnormal protein aggregates could form and trigger symptoms in two other diseases. Abnormal protein degradation in Parkinson's disease leads to the formation of the deposits increasingly linked to disease, according to Ted Dawson of Johns Hopkins University. Researchers in Ronald Wetzel's laboratory at the University of Tennessee in Knoxville showed that neurons died if aggregates of the polyglutamine protein accumulated in the nucleus but not in the cytoplasm.

Repeating the idea that neuroscience is about making connections, the opening lecture by Carla Shatz of Harvard Medical School addressed the key role for immune recognition proteins in building the normal brain during development. Immune molecules may also be critical in pheromone detection, according to unpublished results from expert Catherine Dulac.

The increasing drive to connect neuroscience with other scientific communities was perhaps best illustrated here at a symposium on brain cancer. Oncologists studying difficult-to-treat brain cancers are finding their research increasingly dependent on techniques and basic understandings of the brain developed by neuroscientists. According to Terry Van Dyke of the University of North Carolina in Chapel Hill, who works on astrocytomas, "We can't function as islands and learn very much anymore."