The present study was designed to test whether human auditory brain-stem responses (ABRs) are sensitive to peripheral endocrine signals as reflected by changes in the plasma glucocorticoid concentration. ABRs were recorded following treatment with 50 mg hydrocortisone or placebo in 13 healthy male adults. Experiments were double-blind and designed according to a latin-square within-subject comparison. Treatment was applied 1 h prior to testing as an i.v. infusion over a period of 20 min. Subjects were tested in each session under 3 X 3 conditions, i.e., ABRs were obtained to series of clicks presented at 3 different intensities (80, 60, 40 dB HL) and with 3 different stimulus rates (39, 10, 5 clicks/sec). Additionally, oral temperature was monitored. Hydrocortisone significantly reduced latencies of waves III, V, and VI (and subsequent negative troughs) when low stimulus intensities were used. Furthermore, the glucocorticoid reduced latencies of waves Vn, VI and VIn when the clicks were presented at a slow stimulus rate. Further studies have to specify the underlying mechanisms of these changes.

Adult↗

PubMedDate not supplied

Vasopressin and oxytocin do not influence early sensory processing but affect mood and activation in man.

Effects of arginine-vasopressin (AVP) and oxytocin (OX) on brainstem and middle latency auditory-evoked potentials (BAEP and MAEP), reflecting early sensory processing within the specific auditory pathways and primary auditory cortex, were investigated. Additionally, subjects rated their feelings of activation and mood on an adjective check list (EWL). The experiments were undertaken in 12 healthy male volunteers, receiving either placebo, 0.15 IU AVP, 0.5 IU AVP or 0.5 IU OX as IV bolus injection according to a within-subject double-blind design. There were no consistent effects of AVP and OX on BAEPs and MAEPs. AVP decreased self-perceived deactivation, fatigue and arousal. Results do not suggest an effect of AVP and OX on early stages of sensory processing, but, consistent with previous studies, demonstrate changes towards increased (self-perceived) general activation following administration of these hormones.

Adult↗