Serotonin release in the caudal nidopallium of adult laying hens genetically selected for high and low feather pecking behavior: an in vivo microdialysis study.
Severe feather pecking (FP) is a detrimental behavior causing welfare problems in laying hens. Divergent genetic selection for FP in White Leghorns resulted in strong differences in FP incidences between lines. More recently, it was shown that the high FP (HFP) birds have increased locomotor activity as compared to hens of the low FP (LFP) line, but whether these lines differ in central serotonin (5-hydroxytryptamine, 5-HT) release is unknown. We compared baseline release levels of central 5-HT, and the metabolite 5-HIAA in the limbic and prefrontal subcomponents of the caudal nidopallium by in vivo microdialysis in adult HFP and LFP laying hens from the ninth generation of selection. A single subcutaneous d-fenfluramine injection (0.5 mg/kg) was given to release neuronal serotonin in order to investigate presynaptic storage capacity. The present study shows that HFP hens had higher baseline levels of 5-HT in the caudal nidopallium as compared to LFP laying hens. Remarkably, no differences in plasma tryptophan levels (precursor of 5-HT) between the lines were observed. d-fenfluramine increased 5-HT levels in both lines similarly indirectly suggesting that presynaptic storage capacity was the same. The present study shows that HFP hens release more 5-HT under baseline conditions in the caudal nidopallium as compared to the LFP birds. This suggests that HFP hens are characterized by a higher tonic 5-HT release.
Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands. Electronic address: m.s.kops@uu.nl.
Marjolein S
MS
Kops
Friedrich Loeffler Institut, Institute for Animal Welfare and Animal Husbandry, Celle, Germany. Electronic address: Joergen.Kjaer@fli.bund.de.
Joergen B
JB
Kjaer
Department of Psychology, Ruhr-University of Bochum, Bochum, Germany. Electronic address: onur.guentuerkuen@ruhr-uni-bochum.de.
Onur
O
Güntürkün
Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands. Electronic address: K.G.C.Westphal@uu.nl.
Koen G C
KG
Westphal
Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands. Electronic address: G.A.H.Korte@uu.nl.
Gerdien A H
GA
Korte-Bouws
Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands. Electronic address: B.Olivier@uu.nl.
Berend
B
Olivier
Adaptation Physiology Group, Wageningen University, Wageningen, The Netherlands. Electronic address: Liesbeth.Bolhuis@wur.nl.
J Elizabeth
JE
Bolhuis
Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, The Netherlands. Electronic address: S.M.Korte@uu.nl.
S Mechiel
SM
Korte
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D001774:Blood Chemical Analysis / Q000379:methods; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D005241:Feathers; D005260:Female; D005277:Fenfluramine / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000097:blood; D017551:Microdialysis; D012701:Serotonin / Q000097:blood*; D018490:Serotonin Agents / Q000494:pharmacology; D013045:Species Specificity; D014364:Tryptophan / Q000097:blood
D018490:Serotonin Agents; D005277:Fenfluramine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan
Adult White Leghorn; Caudal nidopallium; Feather pecking; Genetic selection; In vivo microdialysis; Serotonin