Spinal cord monoaminergic system response to age and cold-acclimatization in muscovy duckling.
The effect of age and cold acclimatization on the regional distribution of monoamines in duckling spinal cord was studied. In thermoneutral controls (TN), the high dopamine (DA) to norepinephrine (NE) ratios (0.25 at 4 weeks of age and 0.15 at 6 weeks of age) suggest the presence of specific (non precursor) dopaminergic pools in cervical spinal cord. DA levels and the ratio of DA to NE were lowered by age and cold exposure in the cervical cord. In TN ducklings, serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) showed a decline with age in the spinal cord, indicating that this system is affected with development, whereas cold exposure prevents this decrease. The contents of 5-HT (+58%), 5-HIAA (+93%) and the ratio of 5-HIAA to 5-HT (+50%) are higher in the cervical spinal cord of cold acclimated than in TN ducklings. These results indicate that central monoaminergic systems are markedly affected by age and cold exposure.
Abdelmelek
H
H
Laboratoire de Physiologie des Régulations Energétiques, Cellulaires et Moléculaires UMR 5578 CNRS, Villeurbanne, France.
Cottet-Emard
J M
JM
Pequignot
J M
JM
Barré
H
H
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000064:Acclimatization / Q000502:physiology*; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D015306:Biogenic Monoamines / Q000378:metabolism*; D002574:Cervical Vertebrae; D003080:Cold Temperature / Q000009:adverse effects*; D004298:Dopamine / Q000378:metabolism; D004372:Ducks / Q000033:anatomy & histology / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008159:Lumbar Vertebrae; D008297:Male; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D022722:Thermogenesis / Q000502:physiology*; D013904:Thoracic Vertebrae
D015306:Biogenic Monoamines; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine