Insects, including cockroaches, self-select a balanced diet when faced with different nutrient choices. For self-selection to be carried out effectively, insects possess neuroregulatory systems to control their food intake. In the present study, we examined the role of the neurotransmitter @entity935 (DA) in the feeding regulation of the Madeira cockroach (Rhyparobia maderae). When R. maderae nymphs were injected with 20  l of 100 mmol l(-1) DA, they showed an 83.3% reduction in @entity969 intake and a 78.9% reduction in total intake compared with saline-injected controls. The DA agonist, @entity70519 (6,7-ADTN) (100 mmol l(-1) in 1  l), caused a significant reduction in @entity969 feeding, reducing feeding by 47.3% compared with saline-injected controls. Protein feeding was also significantly reduced by 6,7-ADTN to 62%. Rhyparobia maderae nymphs injected with the DA antagonist @entity2644 (100 mmol l(-1) in 1  l) did not differ significantly from control nymphs in their feeding behavior. Interestingly, R. maderae nymphs injected with 2  l or 5  l @entity2644 (100 mmol l(-1)) showed significantly increased mortality rates of 47.5% or 66.7%, respectively. The DA antagonist, @entity11054 (100 mmol l(-1) in 1  l), caused a significant feeding response, showing an increase in feeding in both @entity969 (310.6%) and total intake (236.3%). Casein feeding in R. maderae nymphs was also elevated (70.8%) but this was not statistically significant. The experiments with DA, the DA agonist @entity70519 and the DA antagonist @entity11054 strongly suggest that the neurotransmitter DA is involved in regulating feeding in the cockroach R. maderae.

XXXX as an anorectic neuromodulator in the cockroach Rhyparobia maderae.

@entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity11054 :: ('MESH:D013134', 'Chemical') :: ['spiperone'] @entity70519 :: ('MESH:C011639', 'Chemical') :: ['6,7-ADTN', '2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene'] @entity2644 :: ('MESH:D002746', 'Chemical') :: ['chlorpromazine'] @entity969 :: ('MESH:D013395', 'Chemical') :: ['sucrose']
@entity935 :: (MESH:D004298,Chemical) :: ['Dopamine']
