Hyper-reactive hypothalamo-pituitary-adrenocortical axis in rats bred for high anxiety-related behaviour
by
Landgraf R, Wigger A, Holsboer F, Neumann ID
Max Planck Institute of Psychiatry,
Munich, Germany.
Landgraf@MPIPSKYL.MPG.DE
J Neuroendocrinol 1999 Jun; 11(6):405-7

ABSTRACT

Psychiatric patients suffering from anxiety disorders or endogenous depression exhibit increased activity in their hypothalamo-pituitary-adrenocortical (HPA) axis. Recently, two Wistar rat lines, bred for high (HAB) and low (LAB) anxiety-related behaviour on the elevated plus-maze, were described as a unique psychopathological animal model (1). The present study focused on the HPA axis reactivity of HAB and LAB animals to an emotional stressor. Thus, adult male HAB and LAB animals, fitted with jugular vein catheters 5 days prior to the experiment, were exposed to an open arm of the elevated plus-maze for 5 min. Whereas basal levels of ACTH and corticosterone were similar in both lines, HAB rats showed higher plasma concentrations at 5 and 15 min following stressor exposure (both hormones and both time points: P<0.01 vs LAB). Furthermore, increased basal (P<0.05 vs LAB) and stimulated (P<0.01 vs LAB) prolactin concentrations in HAB rats were found. In contrast to ACTH, corticosterone and prolactin, plasma oxytocin and vasopressin levels did not differ between HAB and LAB animals; oxytocin, but not vasopressin, responding to open arm exposure with a significant increase in both lines (P<0.05). In conclusion, particularly due to the association between inborn anxiety and HPA axis hyper-reactivity, the HAB rat represents a promising animal model for further investigation of the relationship between emotional disturbance and neuroendocrine activity.

CRF
Love
HPLA
LHPA
Newborns
Noradrenaline
Corticosteroids
Cuddle hormone
The power of love
Oxytocin: structure
Cushing's syndrome
Hippocampal remodelling
Glucocorticoids and mood
The oxytocin receptor system
Love as an emergent property
HPA axis, serotonin and suicide
Oxytocin and social interaction
Oxytocin, addiction and the science of love