Inhibitory effects of caffeine on gustatory plasticity in the nematode Caenorhabditis elegans

Abstract

The effects of caffeine on salt chemotaxis learning were investigated using the nematode Caenorhabditis elegans. To estimate the degree of salt chemotaxis learning, nematodes were placed in a mixed solution of NaCl and caffeine, and then the chemotaxis index of NaCl was obtained from the nematodes placed on agar medium after pre-exposure to caffeine concentrations of 0.01, 0.1, 0.3, and 1.0%. Locomotor activity and preference behavior for caffeine were also estimated under these caffeine conditions. Nematodes pre-exposed to 0.3% caffeine showed inhibition of salt chemotaxis learning. Additional experiments indicated that nematodes showed a preference response to the middle concentration of caffeine (0.1%), with preference behavior declining in the 0.3% caffeine condition. Stable locomotor activity was observed under 0.01-0.3% caffeine conditions. These results suggest that salt chemotaxis learning with 0.3% caffeine is useful for investigating the effects of caffeine on learning in nematodes.

Application of Fluorescence Microscopy and Behavioral Assays to Demonstrating Neuronal Connectomes and Neurotransmitter Systems in C. elegans

“…-Spotting method: This is done by directly applying small drops of the chosen concentration of NaCl to a side of the assay plate at an equidistant point from the control region [93,91].…”

“…Then animals are maintained at 20 °C for 15 mins in their respective pre-exposure wash solutions. Thereafter, wash once with buffer without NaCl for 60 secs at 450 × g for 60 secs; this is to remove the NaCl from the body of the worms [91,93] • Wash animals collected from NGM in a centrifuge three times using 1.5ml tubes for 20 secs at ~900 × g Do not count clumped worms left in the midline (center point) of the assay plate while calculating the chemotaxis index, as these consist of wash-injured animals.…”

A Food Supplement with Antioxidative Santa Herba Extract Modulates Energy Metabolism and Contributes to Weight Management

“…27,28 Furthermore, caffeine is able to stimulate locomotor activity in C. elegans and mice. 29,30 In adipocytes, adenosine could inhibit lipolysis as mediated by adenosine receptors. 31 Accordingly, ADORA2A inhibition might trigger lipolysis in adipocytes and lead to a body fat and body weight reduction.…”

Kahweol Reduces Food Intake of Caenorhabditis elegans

“…There is some evidence that consumption of coffee is linked to reduced food intake, especially in overweight/obese subjects but its effects on feeding behavior are still debatable. ,, The psychostimulant effects of caffeine are suggested to be associated with a decreased food intake, since its effects as the adenosine receptor antagonist can lead to an increase of dopamine and serotonin levels to influence feeding behavior. − A previous report shows that unfiltered coffee from Arabica coffee beans, but not a mixture of phenolic acids and trigonelline found in coffee, reduced the food intake and body weight in high-fat-/high-fructose-fed rats . Thus, both kahweol, as seen in the current study, and caffeine may contribute for the reduction of food intake by coffee.…”