Navigation Links
Inside the brain of a crayfish
Date:9/2/2007

Voyage to the bottom of the sea, or simply look along the bottom of a clear stream and you may spy lobsters or crayfish waving their antennae. Look closer, and you will see them feeling around with their legs and flicking their antennules the small, paired sets of miniature feelers at the top of their heads between the long antennae. Both are used for sensing the environment. The long antennae are used for getting a physical feel of an area, such as the contours of a crevice. The smaller antennules are there to both help the creature smell for food or mates or dangerous predators and also to sense motion in the water that also could indicate the presence of food, a fling or danger. The legs also have receptors that detect chemical signatures, preferably those emanating from a nice hunk of dead fish.

They constantly flick their antennules, says DeForest Mellon, a University of Virginia biology professor, as he watches a Southern swamp crayfish in a bucket doing just that. It is doing two things that are processed simultaneously in the brain as he flicks: smelling the water, and also sensing motion in the water, which can indicate the presence of food or other things of interest. Im interested in understanding how these senses are combined and interpreted in the brain of these animals. My question is, how does the brain detect, integrate and use co-joined but dissimilar sensory inputs" Its much like humans tasting food by a combination of senses that detect taste, aroma, texture and how good that dish of pasta looks. Its a complex process of brain processing that serves us well in a world of smells, textures, flavors and visual stimuli. Its not much different with crustaceans, though their brains are much simpler, which makes them a great study model, Mellon says.

Mellon, and other neurophysiology researchers commonly use crustaceans to try to gain basic understanding of the nervous systems of creatures in general, and, wherever possible, for extrapolating what they find to a basic understanding of the much more complex human brain. All animals, from single-celled amoebas to humans, use similar cellular processes to interpret their olfactory environment.

Due to the large-sized nerve cells of invertebrates, we can conveniently and practically examine these systems that are largely the same among all creatures, Mellon says. And antennule flicking can serve as a practical model that helps us understand how two or more senses work together in the brain. Mellon has been investigating sensory systems for half a century, since his grad school days at Johns Hopkins University. Hes still learning. We can say we know that animals use their senses to make maps of their environment that direct their behaviors, he says.

Recently Mellon perused the research in the field his own and that of many other scientists of the past 45 years or so and has published a review of the literature in the August 2007 issue of The Biological Bulletin. What hes found is that there is still a lot not understood. Its fertile ground for ongoing research, he said. The size of an area of the brain devoted to a particular sense gives us a good idea of how an animal perceives the world. It provides insight as to how the world is interpreted by that animal.

About 40 percent of a crustaceans brain is devoted to the sense of smell. This shows how important detecting odors is to the animal, Mellon says. Crayfish and lobsters are generally solitary creatures, inhabiting an aquatic environment that is often dark, and they need that highly acute sense of smell. Humans, by contrast, have a very small portion of the brain devoted to interpreting smells, less than one percent by volume. But about 30 percent of the human brain is concerned with visual processing, interpreting images from the eye, Mellon says. As social animals, humans rely heavily on sight and color for identifying food, as well as friends and foe.

I have always been fascinated by the diversity of animal types and their equally diverse behaviors, Mellon says. Both are genetically based. And through often very subtle adoption of genetic variations in different animals, evolution has arrived at different solutions to common survival problems. This behavioral diversity and the variants in nervous system organization account for why I remain fascinated with biology.


'/>"/>
Contact: Fariss Samarrai
samarrai@virginia.edu
434-924-3778
University of Virginia
Source:Eurekalert

Related biology news :

1. Nano-Probes Allow an Inside Look at Cell Nuclei
2. Molecule that usually protects infection-fighting cells may cause plaque deposits inside arteries
3. Scientists reveal how disease bacterium survives inside immune system cell
4. The molecular post office inside the cell
5. Sleeping sickness parasite shows how cells divide their insides
6. Cellular scale drug delivery from the inside out
7. Common bacteria pirate natural mechanism to get inside cells
8. Clues to breast cancer hidden inside stem cells
9. Inside rocks, implications for finding life on Mars
10. Tiny shock absorbers help bacteria stick around inside the body
11. Schepens scientists are first to discover angiogenesis switch inside blood vessel cells
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/15/2016)... , Dec. 15, 2016 Advancements ... experience, health wellness and wellbeing (HWW), and ... in three new passenger vehicles begin to ... gesture recognition, heart beat monitoring, brain wave ... facial monitoring, and pulse detection. These will ...
(Date:12/12/2016)... 2016  Researchers at Trinity College, Dublin, are ... combining the material with Silly Putty. The mixture (known ... able to sense pulse, blood pressure, respiration, and ... The research team,s findings were published ... http://science.sciencemag.org/content/354/6317/1257 ...
(Date:12/7/2016)... India , December 7, 2016 According to a ... Machine Learning), Software Tool (Facial Expression, Voice Recognition), Service, Application Area, End User, ... is estimated to grow from USD 6.72 Billion in 2016 to USD 36.07 ... Continue Reading ... ...
Breaking Biology News(10 mins):
(Date:1/19/2017)... Research and Markets has announced the addition ... Type, Application - Global Opportunity Analysis and Industry Forecast, 2014-2022" ... ... is projected to reach $15,737 million by 2022 from $6,521 in ... Omic technologies segment accounted for more than half ...
(Date:1/19/2017)... SHANGHAI , Jan. 19, 2017 /PRNewswire -- ... medical device open-access capability and technology platform, today ... a leading biology focused preclinical drug discovery contract ... Biosciences will become a wholly-owned subsidiary of WuXi, ... core competences and providing greater services. The acquisition ...
(Date:1/19/2017)... ... January 19, 2017 , ... November Research Group, LLC, ... and medical device manufacturers and regulators, is proud to announce the worldwide release ... client designed to provide product vigilance departments with the flexibility and ease of ...
(Date:1/19/2017)... MAYNARD, Mass. , Jan. 19, 2017 ... company focused on enhancing productivity in aquaculture and a ... ), announces that it has completed the listing of ... finalized the equity subscription from Intrexon. "AquaBounty,s ... Company that will broaden our exposure to the U.S. ...
Breaking Biology Technology: