Testosterone-driven seasonal regulation of vasopressin and galanin in the bed nucleus of the stria terminalis of the Djungarian hamster (Phodopus sungorus)

The photoperiod-driven testosterone rhythm thus appears to be a major regulator of extra-hypothalamic vasopressin and galanin in the Djungarian hamster. The long delay between mRNA recovery in the cell body and the neuropeptide recovery in the target areas may be due to progressive filling up of the axon terminals. Alternatively, this delay might be indicative of a seasonal structural plasticity.