Understanding the effects of opioids vs non-opioids in the treatment of neonatal abstinence syndrome, an in vitro model.

Neonatal abstinence syndrome (NAS) refers to cadre of withdrawal manifestations in infants born to mothers who used illicit and licit substances during pregnancy. The increasing prevalence of NAS has been largely due to the maternal use of opioids during pregnancy. NAS contributes to increased morbidity and long-term disability in surviving infants.

Food restriction during development delays puberty but does not affect adult seasonal reproductive responses to food availability in Siberian hamsters (Phodopus sungorus).

Seasonally breeding animals respond to environmental cues to determine optimal conditions for reproduction. Siberian hamsters (Phodopus sungorus) primarily rely on photoperiod as a predictive cue of future energy availability. When raised in long-day photoperiods (>14 h light), supplemental cues such as food availability typically do not trigger the seasonal reproductive response of gonadal regression, which curtails reproduction in unsuitable environments.

Estradiol regulates daily rhythms underlying diet-induced obesity in female mice.

The circadian system is a critical regulator of metabolism and obesity in males, but its role in regulating obesity in females is poorly understood. Because there are sex differences in the development of obesity and susceptibility to obesity-related disorders, we sought to determine the role of estrogens in regulating the circadian mechanisms underlying diet-induced obesity. When fed high-fat diet, C57BL/6J male mice gain weight, whereas females are resistant to diet-induced obesity.

Endotoxin rapidly desensitizes the gonads to kisspeptin-induced luteinizing hormone release in male Siberian hamsters ().

Activation of the immune system induces rapid reductions in hypothalamic-pituitary-gonadal (HPG) axis activity, which in turn decreases secretion of sex steroids. This response is likely adaptive for survival by temporarily inhibiting reproduction to conserve energy; however, the physiological mechanisms controlling this response remain unclear. The neuropeptide kisspeptin is a candidate to mediate the decrease in sex hormones seen during sickness through its key regulation of the HPG axis.

The Effects of Perinatal Oxycodone Exposure on Behavioral Outcome in a Rodent Model.

Opiate addiction is now a major public health problem. Perinatal insults and exposure to opiates such as morphine are well known to affect development of the hypothalamic-pituitary-adrenal axis of the offspring adversely and are associated with a higher risk of developing neurobehavioral problems. Oxycodone is now one of the most frequently abused pain killers during pregnancy; however, limited data are available regarding whether and how perinatal oxycodone exposure (POE) alters neurobehavioral outcomes of the offspring.

Effects of exogenous leptin on seasonal reproductive responses to interacting environmental cues in female Siberian hamsters.

Animals living in temperate climates respond to environmental cues that signal current and future resource availability to ensure that energy resources are available to support reproduction. Siberian hamsters (Phodopus sungorus) undergo robust gonadal regression in short, winter-like photoperiods as well as in response to mild food restriction in intermediate photoperiods. The goal of the present study was to investigate whether leptin is a relevant metabolic signal in regulating gonadal regression in response to diminishing food availability.

Circadian rhythm disruption by a novel running wheel: roles of exercise and arousal in blockade of the luteinizing hormone surge.

Exposure of proestrous Syrian hamsters to a new room, cage, and novel running wheel blocks the luteinizing hormone (LH) surge until the next day in ~75% of hamsters [1]. The studies described here tested the hypotheses that 1) exercise and/or 2) orexinergic neurotransmission mediate novel wheel blockade of the LH surge and circadian phase advances. Female hamsters were exposed to a 14L:10D photoperiod and activity rhythms were monitored with infra-red detectors.

Gonadotropin-inhibitory hormone reduces sexual motivation but not lordosis behavior in female Syrian hamsters (Mesocricetus auratus).

Reproductive success is maximized when female sexual motivation and behavior coincide with the time of optimal fertility. Both processes depend upon coordinated hormonal events, beginning with signaling by the gonadotropin-releasing hormone (GnRH) neuronal system. Two neuropeptidergic systems that lie upstream of GnRH, gonadotropin-inhibitory hormone (GnIH; also known as RFamide related peptide-3) and kisspeptin, are potent inhibitory and excitatory modulators of GnRH, respectively, that participate in the timing of the preovulatory luteinizing hormone (LH) surge and ovulation.

Effects of perinatal oxycodone exposure on the cardiovascular response to acute stress in male rats at weaning and in young adulthood.

Unlabelled: Oxycodone (OXY) is one of the most commonly abused opiates during pregnancy. Perinatal opiate exposure (POE) is associated with neurobehavioral and hormone changes. Little is known about the effects of perinatal OXY on the cardiovascular (CV) responses to stress.

Effects of perinatal cocaine exposure on open field behavior and the response to corticotropin releasing hormone (CRH) in rat offspring.

Previous reports indicate that prenatal cocaine exposure alters specific behaviors and hypothalamic-pituitary-adrenal axis (HPA) function in the offspring. In most previous studies, cocaine was given via subcutaneous injections. However intravenous administration more closely mimics human cocaine abuse during pregnancy.

Phenobarbital blockade of the preovulatory luteinizing hormone surge: association with phase-advanced circadian clock and altered suprachiasmatic nucleus Period1 gene expression.

The suprachiasmatic nucleus (SCN) controls the timing of the preovulatory luteinizing hormone (LH) surge in laboratory rodents. Barbiturate administration during a critical period on proestrus delays the surge and prolongs the estrous cycle 1 day. Because a nonphotic timing signal (zeitgeber) during the critical period that phase advances activity rhythms can also induce the latter effect, we hypothesized that barbiturates delay the LH surge by phase-advancing its circadian timing signal beyond the critical period.

Effects of perinatal oxycodone exposure on the response to CRH in late adolescent rats.

We hypothesized that prenatal oxycodone exposure suppresses the Hypothalamic-Pituitary-Adrenal (HPA) response to stress in late adolescence. Dark Agouti rats were given either intravenous oxycodone or vehicle (controls, CON) daily from gestation day 8 until postnatal day (PD) 5. At PD 45, the male and female offspring received intravenously either ovine corticotropin releasing hormone (CRH) or saline.

Pituitary gonadotroph estrogen receptor-alpha is necessary for fertility in females.

Estrogens play a central role in regulating female reproduction throughout the reproductive axis, and the pituitary is one of the major targets of estrogen action. We hypothesized that estrogen receptor alpha (ERalpha) mediates estrogen action in the pituitary gonadotroph. To test this hypothesis, we generated a mouse line with a selective ERalpha deletion in the gonadotropin alpha-subunit (alphaGSU)-expressing pituitary cells (pituitary-specific ERalpha knockout; ERalpha(flox/flox) alphaGSU(cre)).

Modulation of hypoglycemia-induced increases in plasma epinephrine by estrogen in the female rat.

Clinical studies have demonstrated that estrogen replacement therapy suppresses stress-induced increases in plasma catecholamines. The present study determined whether normal circulating levels of estrogen can modulate hypoglycemia-induced increases in plasma epinephrine (EPI). In anesthetized female rats, insulin-induced hypoglycemia (0.

An in vivo microdialysis study of light/dark-modulation of vitreal dopamine release in zebrafish.

Dopamine (DA) is an important neuromodulator in the visual system. The release of DA in the retina largely depends on environmental lighting conditions. Most previous studies have assessed the effect of illumination on retinal DA or its metabolites using homogenates or in vitro preparations.

Loss of luteinizing hormone surges induced by chronic estradiol is associated with decreased activation of gonadotropin-releasing hormone neurons.

Chronic exposure of young ovariectomized rats to elevated circulating estradiol causes loss of steroid-induced LH surges. Such LH surges are associated with cFos-induced activation of GnRH neurons; therefore, we hypothesized that chronic estradiol treatment abolishes LH surges by decreasing activation of GnRH neurons. Regularly cycling rats were ovariectomized and immediately received an estradiol implant or remained untreated.