Synaptosomal uptake of hypothalamic monoamines and recovery of pituitary-adrenal activity following medial forebrain bundle lesions in rats.
The normal diurnal variation in plasma corticosterone (COR) was abolished and the response to ether stress was enhanced at 3 days following the production of medial forebrain bundle (MFB) lesions in male rats. However, by 7 days following surgery, basal plasma COR levels and the response to ether stress appeared normal. These alterations and subsequent recovery of pituitary-adrenal activity were accompanied by decreasing hypothalamic synaptosomal uptake of serotonin (5HT) and increasing synaptosomal uptake of dopamine (DA), evident at 3 and continuing at 7 days following the lesion. Uptake of norepinephrine (NE) was not affected at 3 days but showed a reduction at 7 days following surgery. The results suggest that disruption of ascending 5HT and NE fibers to the hypothalamus can alter pituitary-adrenal activity but that normal activity recovers by 7 days following the lesion. The correlation between recovery of pituitary-adrenal activity and increases in the normal uptake of hypothalamic DA suggest that DA may interact with 5HT and NE systems in the normal control of adrenocorticotrophin (ACTH) release.
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D001931:Brain Mapping; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood*; D004298:Dopamine / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D008474:Medial Forebrain Bundle / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D013574:Synaptosomes / Q000378:metabolism
D001679:Biogenic Amines; D012701:Serotonin; D004298:Dopamine; D003345:Corticosterone; D009638:Norepinephrine