Food intake and biogenic amine concentrations in brain regions of chicks following intracerebroventricular injection of six-hydroxydopamine.
The effect of catecholamine depletion within three brain regions on subsequent food intake and body weight gain were investigated in two week-old chicks. Two levels of pargyline (P; 50 mg/kg and 100 mg/kg intraperitoneally) and three levels of six-hydroxydopamine (6-OHDA; 0, 200 micrograms (136 free base) and 300 micrograms (204 free base) intracerebroventricularly) were administered to 36 chicks (n = 6 per treatment). The greatest reduction in food intake and body weight gain occurred in the group given 100 mg/kg P, 300 micrograms 6-OHDA. These chicks displayed an average aphagic response of 4.5 days. Chicks given the higher drug doses were hyperactive when handled and displayed difficulty in orienting their bills when attempting to consume pellets. Biogenic amines were determined in three brain regions (striatum, hypothalamus and brainstem) using high pressure liquid chromatography with electrochemical detection. Dopamine (DA) was reduced (p less than 0.05) in the striatum of all groups treated with 6-OHDA when compared to their respective controls. Significant depletions of norepinephrine (NE) occurred in all three brain regions in all groups treated with 6-OHDA when compared with their respective control groups (p less than 0.05). In contrast, striatal epinephrine levels were elevated in chicks given 100 mg P plus 6-OHDA. It is proposed that depletions of both DA and NE contribute to the aphagic or anorexic response of chicks following administration of the neurotoxin 6-OHDA.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001923:Brain Chemistry / Q000187:drug effects*; D001933:Brain Stem / Q000187:drug effects; D002645:Chickens; D003337:Corpus Callosum / Q000187:drug effects; D004298:Dopamine / Q000032:analysis*; D004435:Eating / Q000187:drug effects*; D004837:Epinephrine / Q000032:analysis*; D006892:Hydroxydopamines / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects; D008297:Male; D016627:Oxidopamine; D010293:Pargyline / Q000494:pharmacology
D006892:Hydroxydopamines; D016627:Oxidopamine; D010293:Pargyline; D004298:Dopamine; D004837:Epinephrine