The inherent electrical resistance of the rat vaginal wall rises markedly near the beginning of estrus and then falls again to low levels for the remainder of the ovarian cycle. Accordingly, special instruments have been developed to measure such resistances (within seconds) on simply inserting a small probe fitted with a pair of recording electrodes into the vagina (i.e., the MK-10A impedance ...

Periodic oscillations of gonadal hormone levels during the estrous cycle exert effects on the female brain, impacting cognition and behavior. While previous research suggests that changes in hormone levels across the cycle affect dendritic spine dynamics in the hippocampus, little is known about the effects on cortical dendritic spines and previous studies showed contradictory results. In this ...

The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyomet...

OBJECTIVES A novel denervation technique of ovarian was used in rats to investigate its effects on sexual cycle, pregnancy rates and offspring numbers. SETTING AND DESIGN A total of 34 female albino rats were included. Animals were divided into 3 groups. METHODS In group 1, ovaries were bilaterally denervated. Animals in group 2 underwent sham operation and group 3 comprised of controls. Se...

Zabka, A. G., M. Behan, and G. S. Mitchell. Selected Contribution: Time-dependent hypoxic respiratory responses in female rats are influenced by age and by the estrus cycle. J Appl Physiol 91: 2831–2838, 2001.—Age affects time-dependent respiratory responses to episodic hypoxia in male rats, particularly long-term facilitation (LTF), a serotonindependent respiratory “memory” [Zabka AG, Behan M,...

Rationale: Fast-transient outward K (Ito,f) and ultrarapid delayed rectifier K currents (IK,slow, also known as IKur) contribute to mouse cardiac repolarization. Gender studies on these currents have reported conflicting results. Objective: Key missing information in these studies is the estral stage of the animals. We revisited gender-related differences in K currents, taking into consideratio...