
From snail to man, one of the hallmarks of the brain is the ease with which behavioral variants are generated--for example, humans can easily walk with different stride lengths or different speeds. By studying how a relatively simple motor network of the marine snail Aplysia produces variants of a particular feeding behavior, researchers have found that the ability to generate a large number of behavioral variants stems from the elegant hierarchical architecture of the brains motor network.
Most motor systems are organized into a hierarchy of at least two layers of neurons, with higher-order neurons acting on lower-order neurons, which form a small number of building blocks or modules that produce a variety of behaviors. However, it was not clear how variants of a single motor act are generated in such a hierarchical system.
In the new work, Jian Jing and Klaudiusz Weiss of the Mount Sinai School of Medicine in New York studied the feeding network of Aplysia, which exhibits a biting behavior in response to the presence of food. The researchers showed that within the feeding network, two higher-order neurons that are active during biting behavior employ a combinatorial mechanism to produce variations in one particular movement parameter of the biting behavior. The researchers showed that, tellingly, these higher-order neurons accomplish their roles through their specific actions on two groups of lower-order interneurons that directly influence the particular biting-behavior movement parameter. Therefore, in this system, and likely others, the generation of large numbers of behavioral variants is characterized by higher-order neurons that flexibly combine an "alphabet system" of outputs that are generated by lower-order modules within the brains motor network.
Heidi Hardman | Source: EurekAlert!
Further information: www.current-biology.com
More articles from Life Sciences:
Scientists Unravel Evolution of Highly Toxic Box Jellyfish
20.11.2009 | NOAA Fisheries Northeast Fisheries Science Center
Texas A&M Researchers Examine How Viruses Destroy Bacteria
20.11.2009 | Texas A&M University
Scientists Unravel Evolution of Highly Toxic Box Jellyfish
20.11.2009 | Life Sciences
When good companies do bad things: Examining illegal corporate behavior
20.11.2009 | Business and Finance
UCR plant scientist's research spawns new discoveries showing how crops survive drought
20.11.2009 | Agricultural and Forestry Science
Multidisciplinary meeting on Urological Cancers aims to benefit cancer patients
20.11.2009 | Event News
'Golden Age' for clinical psychology in Northern Ireland
20.11.2009 | Event News
New Perspectives in Marine Anti-Fouling Research
11.11.2009 | Event News