Figure 1
From: A ghrelin–growth hormone axis drives stress-induced vulnerability to enhanced fear
Stress-related changes in fear and ghrelin are independent of adrenal stress hormones. Animals received adrenalectomy (ADX) or sham surgery (SHAM). After at least a week of recovery, animals received either 14 days (4 h per day) of immobilization stress (STR) or gentle handling (no stress (NS)). (a) Some animals received auditory Pavlovian fear conditioning 24 h after the last stress or handling session. (b) Fear to the tone was assessed 48 h later in a novel context. In a separate group of animals, trunk blood was collected 24 h after the last stress session. Plasma level corticosterone (c) and acylated ghrelin (d) were determined with enzyme-linked immunosorbent assay (ELISA). All data are mean±s.e.m. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001, ∼P<0.10 in planned comparisons.
