title: Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity.
abstract: Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reactive coping strategy, respectively. Therefore, at approximately 4 weeks of age, the behavior of 48 LFP and 48 HFP chicks in response to an APO injection was studied using an open field. Another objective of the present study was to determine whether behavioral variation (in an open field) between HFP and LFP birds, after APO injection, is also reflected by variation of D(1) and D(2) receptor densities in the brain. Receptor binding capacities were assessed by measuring specific binding of tritiated D(1) and D(2) receptor ligands in different regions of the brain of control HFP and LFP chicks. In the present study, it is shown that indeed HFP chicks display a more enhanced behavioral response to acute APO treatment (0.5 mg/kg BW) than LFP birds in an open field. This difference was not reflected by variation of D(1) and D(2) receptor densities in the brain between both lines.
authors.affiliation: Animal Sciences Group of Wageningen UR, Division of Animal Resources Development, Research group Animal Welfare, P.O. Box 65, NL-8200, AB Lelystad, The Netherlands. yvonne.vanhierden@wur.nl
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: van Hierden
authors.forename: Jaap M
authors.initials: JM
authors.lastname: Koolhaas
authors.forename: L'ubor
authors.initials: L
authors.lastname: Kost'ál
authors.forename: Pavel
authors.initials: P
authors.lastname: Výboh
authors.forename: Monika
authors.initials: M
authors.lastname: Sedlacková
authors.forename: Marek
authors.initials: M
authors.lastname: Rajman
authors.forename: Marian
authors.initials: M
authors.lastname: Juráni
authors.forename: S
authors.initials: S
authors.lastname: Mechiel Korte
mesh_terms: D000223:Adaptation, Psychological / Q000187:drug effects; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001143:Arousal / Q000187:drug effects; D001921:Brain / Q000187:drug effects; D002645:Chickens / Q000235:genetics*; D004298:Dopamine / Q000502:physiology*; D005106:Exploratory Behavior / Q000187:drug effects; D005241:Feathers; D005260:Female; D011334:Proactive Inhibition; D011931:Reactive Inhibition; D017447:Receptors, Dopamine D1 / Q000187:drug effects; D017448:Receptors, Dopamine D2 / Q000187:drug effects; D012931:Social Environment; D013045:Species Specificity; D013239:Stereotyped Behavior / Q000187:drug effects*
chemical_list: D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D001058:Apomorphine; D004298:Dopamine