Effects of hypothalamically elicited emotional behaviors on the plasma levels of estradiol and IGF-1.
We examined changes in the plasma levels of estradiol (E2), insulin-like growth factor-1 (IGF-1), ACTH, cortisol and catecholamines accompanying various kinds of hypothalamically elicited emotional behaviors in female cats. The emotional behaviors consisting of restlessness, threat and searching-biting (S-B) were elicited intermittently for 6 h by electrical stimulation of the anterior hypothalamus (AH), ventromedial hypothalamus (VMH) and lateral hypothalamus (LH), respectively, in awake and free-moving conditions. The blood was sampled three times immediately before, 1 h after and 6 h after the start of stimulation. The plasma levels of ACTH, cortisol and catecholamines significantly increased in both restlessness and threat behaviors, whereas in the S-B behavior, the ACTH level significantly increased, while the cortisol level showed a slight nonsignificant increase. No changes were observed in the plasma catecholamine levels in the S-B behavior. The plasma E2 level significantly increased in threat behavior after 1 and 6 h of stimulation compared to the prestimulation levels, and the level also increased in comparison to the control group after 1 h. In contrast, the restlessness and S-B behaviors had little or no effect on the E2 level. No significant changes were observed in the plasma levels of IGF-1 in all behavior groups. These findings suggest that various hypothalamically elicited emotional behaviors have differential effects on the plasma E2, but not on the IGF-1 levels. Therefore, E2 and IGF-1 are regulated independently of each other.
Mohamed
S
S
Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Fukuoka 812-8582, Maidashi Higashi, Japan. souher@hotmail.com
Kojima
K
K
Fujimaru
Y
Y
Mori
Y
Y
Kaname
H
H
Sumida
Y
Y
Kinukawa
N
N
Tashiro
N
N
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001143:Arousal / Q000502:physiology*; D002415:Cats; D004558:Electric Stimulation; D004644:Emotions / Q000502:physiology*; D004958:Estradiol / Q000502:physiology*; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D007032:Hypothalamus, Anterior / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D009043:Motor Activity / Q000502:physiology; D014697:Ventromedial Hypothalamic Nucleus / Q000502:physiology*
D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone