Intra-accumbens baclofen, but not muscimol, mimics the effects of food withdrawal on feeding behaviour.
Intra-accumbens stimulation of GABA receptors results in a robust increase in food intake. However the differential consequences of stimulating GABA(A) and GABA(B) receptors in the nucleus accumbens have not been extensively explored with respect to feeding behaviour. Here we compare the effects of the GABA(B) receptor agonist baclofen and GABA(A) receptor agonist muscimol, infused into the nucleus accumbens shell, on food intake and related behavior patterns. Baclofen (110-440 ρmol) dose dependently enhanced intake and delayed the onset of satiety within the test period as did the effects of 4-8h food withdrawal. Muscimol (220-660 ρmol) enhanced intake but also disrupted the sequence of associated behaviours at every dose tested. We conclude that GABA(B) receptors in the nucleus accumbens shell may play a role in relation to feeding motivation whereas GABA(A) receptors may, as previously suggested, have a more restricted role in relation to the motor components of approach to food and ingestion.
Pulman
K G T
KG
Schools of Psychology, University of Sussex, Brighton, UK.
Somerville
E M
EM
Clifton
P G
PG
D000818:Animals; D001418:Baclofen / Q000008:administration & dosage*; D004435:Eating / Q000187:drug effects* / Q000502:physiology / Q000523:psychology; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology / Q000523:psychology; D005502:Food; D007276:Injections, Intraventricular; D008297:Male; D009118:Muscimol / Q000008:administration & dosage*; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000502:physiology; D051381:Rats
D009118:Muscimol; D001418:Baclofen