Differential response of GnIH in the brain and gonads following acute stress in a songbird

•GnIH immunoreactivity in the hypothalamus decreased in males and females subjected to acute restraint stress.•Restrained females were found to decrease mRNA expression of the beta subunit of follicle-stimulating hormone.•Restraint stress increased GnIH mRNA expression in the testes of males but not the ovaries of females.•GnIH and GnRH expression in the hypothalamus did not change with treatment, nor differ by sex.