Transcranial magnetic stimulation (TMS) effects on testosterone, prolactin, and corticosterone in adult male rats.
BACKGROUND
Transcranial magnetic stimulation is a relatively new technique for inducing small, localized, and reversible changes in living brain tissue. Although transcranial magnetic stimulation generally results in no immediate changes in plasma corticosterone, prolactin, and testosterone, it normalizes the dexamethasone suppression test in some depressed subjects and has been shown to attenuate stress-induced increases in adrenocorticotropic hormone in rats.


METHODS
In this study, serum corticosterone and testosterone concentrations were assayed in male rats immediately and 3, 6, 9, 12, 24, and 48 hours following a single transcranial magnetic stimulation or sham application. Serum prolactin concentrations were determined immediately and 2 hours following a one-time application of either transcranial magnetic stimulation or sham.


RESULTS
Transcranial magnetic stimulation animals displayed significantly lower corticosterone concentrations at 6 and 24 hours following a single application compared with sham-control values. Transcranial magnetic stimulation also resulted in lower corticosterone concentrations numerically but not statistically in transcranial magnetic stimulation animals immediately after application (p =.089). No significant differences were found between groups for serum prolactin or testosterone levels at any given collection time point.


CONCLUSIONS
These findings 1) suggest that transcranial magnetic stimulation alters the hypothalamic-pituitary-adrenal stress axis and 2) provide time-course data for the implications of the hormonal mechanism that may be involved in the actions of transcranial magnetic stimulation.
Hedges
Dawson W
DW
Department of Psychology and the Neuroscience Center, Brigham Young University, Provo, Utah 84602, USA.
Salyer
David L
DL
Higginbotham
Brian J
BJ
Lund
Trent D
TD
Hellewell
James L
JL
Ferguson
David
D
Lephart
Edwin D
ED
D000818:Animals; D001143:Arousal / Q000502:physiology; D003345:Corticosterone / Q000097:blood*; D004574:Electromagnetic Fields; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology; D011388:Prolactin / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood*
D013739:Testosterone; D011388:Prolactin; D003345:Corticosterone