Odour detection better in food rich environment?
food rich environment worms pay better attention to an 'irritant'
than their starved counterparts, leading to the supposition that a
well-fed human is more attentive.
Researchers in the US uncovered a rapid and reversible chemosensory circuit, regulated by both food and serotonin levels, dependent on the G protein, GPA-11.
"We often behave differently when hungry, but if I feed you pizza you will listen to what I'm saying," Anne C. Hart from the Massachusetts General Hospital Center for Cancer Research, who co-authored the study, explained to FoodNavigator.com.
"Implications for the food industry from the study could be linked to how we perceive odours [and the impact on our behaviours], maybe the basics are conserved from the nematodes to humans," she added.
Under the study well-fed nematodes (roundworms) fled from the noxious smell of the irritant octanol faster than their starved counterparts. The loss of serotonin, which is known to be critical in a nematode response to food, had a similar effect.
"We want to understand how the sense of smell changes and how the nervous system detects sensory stimuli," added Hart.
In a second step for the study the authors selectively removed pairs of neurons thought to be involved in octanol sensing, they found that the presence of food made little difference to the response.
Worms in which the ASH neurons, which express GPA-11, were ablated did not respond to dilute amounts of octanol regardless of the availability of food, they write.
Through their research, the authors demonstrated how food- and serotonin-regulated changes in a neuronal circuit can affect behaviour. In humans, defects in the regulation of the neurotransmitter serotonin have been linked to a number of behavioral problems, including depression and obsessive-compulsive disorder.
Full findings of the study, 'Feeding status and serotonin rapidly and reversibly modulate a Caenorhabditis elegans chemosensory circuit' are published in the 11-15 October 2004 online edition of Proceedings of the National Academy of Sciences.
