Abstract:
The current study set out to investigate the potential effects of olfactory stimuli on the basal
circulating levels of luteinizing hormone (LH) and the response of the pituitary to an
exogenous gonadotropin-releasing hormone (GnRH) challenge in two mole-rat species with
induced ovulation but contrasting mating and social systems. Females were either kept in
isolation, allowed only olfactory and auditory contact or in physical contact with a male. Basal
LH as well as pituitary challenged LH blood samples were collected after six hours.
Post-challenge LH levels were significantly elevated compared to baseline levels in both
species. However, neither basal nor post-challenge LH levels differed significantly between
treatments for females of either species. At the same time, while baseline LH was comparable
between the two species, post-challenge levels were significantly greater for the solitary
species. Our findings negate a modulatory role of male cues on LH levels but suggest increases
in pituitary sensitivity in the solitary species. This could enhance reproductive success in
species with only sporadic encounters between the sexes and merits further studies in other
species.
