Role of testosterone: cortisol ratio in age- and sex-specific cortico-hippocampal development and cognitive performance.

Testosterone (T) and cortisol (C) are steroid hormones that have been argued to play opposing roles in shaping physical and behavioral development in humans. While there is evidence linking T and C to different memory processes during adulthood, it remains unclear how the relative levels of T and C (TC ratio) may influence brain and behavioral development, whether they are influenced by sex of the child, and whether or not they occur as a result of stable changes in brain structure (organizational changes), as opposed to transient changes in brain function (activational changes). As such, we tested for associations among TC ratio, cortico-hippocampal structure, and standardized tests of executive, verbal, and visuo-spatial function in a longitudinal sample of typically developing 4-22-year-old children and adolescents. We found greater TC ratios to be associated with greater coordinated growth (i.e. covariance) between the hippocampus and cortical thickness in several areas primarily devoted to visual function. In addition, there was an age-related association between TC ratio and parieto-hippocampal covariance, as well as a sex-specific association between TC ratio and prefrontal-hippocampal covariance. Differences in brain structure related to TC ratio were in turn associated with lower verbal/executive function, as well as greater attention in tests of visuo-spatial abilities. These results support the notion that TC ratio may shift the balance between top-down (cortex to hippocampus) and bottom-up (hippocampus to cortex) processes, impairing more complex, cortical-based tasks and optimizing visuospatial tasks relying primarily on the hippocampus.

Positive Correlation between nNOS and Stress-Activated Bowel Motility Is Confirmed by In Vivo HiBiT System.

Neuronal nitric oxide synthase (nNOS) has various roles as a neurotransmitter. However, studies to date have produced insufficient data to fully support the correlation between nNOS and bowel motility. This study aimed to investigate the correlation between nNOS expression and gastrointestinal (GI) tract motility using a stress-induced neonatal maternal separation (NMS) mouse model. In this study, we generated a genetically modified mouse with the HiBiT sequence knock-in into the nNOS gene using CRISPR/Cas9 for analyzing accurate nNOS expression. nNOS expression was measured in the stomach, small intestine, large intestine, adrenal gland, and hypothalamus tissues after establishing the NMS model. The NMS model exhibited a significant increase in nNOS expression in large intestine, adrenal gland, and hypothalamus. Moreover, a significant positive correlation was observed between whole gastrointestinal transit time and the expression level of nNOS. We reasoned that NMS induced chronic stress and consequent nNOS activation in the hypothalamic-pituitary-adrenal (HPA) axis, and led to an excessive increase in intestinal motility in the lower GI tract. These results demonstrated that HiBiT is a sensitive and valuable tool for analyzing in vivo gene activation, and nNOS could be a biomarker of the HPA axis-linked lower intestinal tract dysfunction.

Long-Term Stability of Cortisol Production and Metabolism Throughout Adolescence: Longitudinal Twin Study.

Life-course experiences have been postulated to program hypothalamus-pituitary-adrenal (HPA) axis activity, suggesting that HPA axis activity is, at least partially, stable over time. Yet, there is paucity of data on the long-term stability of cortisol production and metabolism. We performed a prospective follow-up study in twins recruited from a nationwide register to estimate the stability of cortisol production and metabolism over time, and the contribution of genetic and environmental factors to this stability. In total, 218 healthy mono- and dizygotic twins were included. At the ages of 9, 12 and 17 years, morning urine samples were collected for assessment (by gas chromatography-tandem mass spectrometry) of cortisol metabolites, enabling the calculation of cortisol metabolite excretion rate and cortisol metabolism activity. Our results showed a low stability for both cortisol metabolite excretion rate (with correlations <.20) and cortisol metabolism activity indices (with correlations of .25 to .46 between 9 and 12 years, -.02 to .15 between 12 and 17 years and .09 to .28 between 9 and 17 years). Because of the low stability over time, genetic and environmental contributions to this stability were difficult to assess, although it seemed to be mostly determined by genetic factors. The low stability in both cortisol production and metabolism between ages 9 and 17 years reflects the dynamic nature of the HPA axis.

Salivary alpha-amylase and cortisol responsiveness to stress in first episode, drug-naïve patients with panic disorder.

Reported findings on reactivity to stress of the sympathetic-adreno-medullar (SAM) and hypothalamic-pituitary-adrenal (HPA) systems in panic disorder (PD) are very variable. This inconsistency may be explained by differences in treatment exposure, illness duration and emotion regulation strategies. The present study examined the reactivity to mental stress of the SAM and HPA axes in a sample of first episode, drug naïve patients with PD which avoids confounds of medications exposure and illness chronicity. Activation of the SAM axis was evaluated by dosage of salivary alpha-amylase (sAA) and heart rate. Activation of the HPA axis was tested by dosage of salivary cortisol. Psychological assessments were done by the Self-Rating Depression Scale, the Self-Rating Anxiety Scale, the State-Trait Anxiety Inventory, the Cope Orientation to Problems Experienced (COPE) Inventory and the 16 Personality Factor Questionnaire (16PF). Patients showed reduced sAA stress reactivity, higher baseline cortisol levels and a more rapid decrease in stress cortisol levels as compared with controls. A significant correlation was found between active coping strategies and cortisol levels (response to stress). The findings suggest that blunted SAM stress reactivity and a rapid decrease in stress cortisol levels reflect traits that may enhance vulnerability to psychopathology in patients with PD.

Association analyses of depression and genes in the hypothalamus-pituitary-adrenal axis.

OBJECTIVE: Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis has been reported in depression. The aim was to investigate the potential association between depression and seven genes regulating or interfering with the HPA axis, including the gene encoding angiotensin converting enzyme (ACE). METHODS: In total, 78 single nucleotide polymorphisms (SNPs) and one insertion/deletion polymorphism were genotyped. The study included 408 individuals with depression and 289 controls. In a subset of cases, the interaction between genetic variants and stressful life events (SLEs) was investigated. RESULTS: After quality control, 68 genetic variants were left for analyses. Four of nine variants within ACE were nominally associated with depression and a gene-wise association was likewise observed. However, none of the SNPs located within AVP, CRH, CRHR1, CRHR2, FKBP5 or NC3C1 were associated with depression. One nominally significant interaction, most likely due to chance, was identified. CONCLUSION: The results indicate that ACE could be a potential candidate gene for depression.

Effect of Prolonged Iodine Overdose on Type 2 Iodothyronine Deiodinase Ubiquitination-Related Enzymes in the Rat Pituitary.

The purpose of this study is to determine the effect of prolonged iodine overdose on type 2 iodothyronine deiodinase (D2) ubiquitination-related enzymes. Male Wistar rats were fed different doses of iodine and were then euthanized at the 4, 8, 12, or 24 weeks (4w, 8w, 12w, or 24w) after iodine administration. Urinary iodine concentration (UIC), thyroid-stimulating hormone (TSH), total thyroxine (TT4), and total triiodothyronine (TT3) were determined. Real-time quantitative RT-PCR and Western blot were used to measure mRNA and protein expression levels of pituitary D2 as well as two D2-specific ubiquitin ligases [WD repeat and SOCS box-containing protein 1 (WSB-1), membrane-associated ring finger (C3HC4) 6 (MARCH6 or TEB4)] and two D2-specific deubiquitinating enzymes [ubiquitin-specific peptidase 20 (USP20) and ubiquitin-specific peptidase 33 (USP33)]. The mRNA and protein expression levels of USP19, a TEB4-specific deubiquitinating enzyme, were also measured. Prolonged high iodine intake significantly increased TSH expression. At 12w, TSH was 1.57-, 1.44-, and 2.11-fold of NI group in 6HI, 10HI, and 50HI groups, respectively. At 24w, TSH had increased to 2.11-fold in the 50HI group. The pituitary D2 protein level decreased at 12w and 24w; though the mRNA level did not change. Prolonged iodine intake increased mRNA and protein expression levels of pituitary WSB-1 and TEB4. High iodine intake had no discernible effects on USP20. Temporary increases in USP33 and USP19 mRNA levels were observed. The enzymes related to D2 ubiquitination change with prolonged high iodine intake. Increased D2 ubiquitination suppresses the activity of D2, causing a decrease in negative feedback of the hypothalamic-pituitary-thyroid axis.

Examining multiple sleep behaviors and diurnal salivary cortisol and alpha-amylase: Within- and between-person associations.

Sleep has been linked to the daily patterns of stress-responsive physiological systems, specifically the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). However, extant research examining sleep and diurnal patterns of cortisol, the primary end product of the HPA axis, has primarily focused on sleep duration with limited attention on other facets of sleep. For example, it is not clear how specific aspects of sleep (e.g., sleep quality, sleep duration variability) are related to specific components of diurnal cortisol rhythms. Salivary alpha-amylase (sAA) has been recognized as a surrogate marker of ANS activity, but limited research has explored relations between sleep and sAA diurnal rhythms. The current study utilized an ecological momentary assessment protocol to examine within- and between-person relations between several facets of sleep behavior using multiple methods (e.g., subjective report, actigraphy) and salivary cortisol and sAA. Older adolescents (N=76) provided saliva samples and diary entries five times per day over the course of three days. Sleep was assessed via questionnaire, through daily diaries, and monitored objectively using actigraphy over a four day period. Between-person results revealed that shorter average objective sleep duration and greater sleep duration variability were related to lower levels of waking cortisol and flatter diurnal slopes across the day. Within-person results revealed that on nights when individuals slept for shorter durations than usual they also had lower levels of waking cortisol the next day. Sleep was not related to the cortisol awakening response (CAR) or diurnal patterns of sAA, in either between-person or within-person analyses. However, typical sleep behaviors measured via questionnaire were related to waking levels of sAA. Overall, this study provides a greater understanding of how multiple components of sleep, measured in naturalistic environments, are related to cortisol and sAA diurnal rhythms, and how day-to-day, within-person changes in sleep duration contribute to daily variations in cortisol.

Differences in hypothalamic type 2 deiodinase ubiquitination explain localized sensitivity to thyroxine.

The current treatment for patients with hypothyroidism is levothyroxine (L-T4) along with normalization of serum thyroid-stimulating hormone (TSH). However, normalization of serum TSH with L-T4 monotherapy results in relatively low serum 3,5,3'-triiodothyronine (T3) and high serum thyroxine/T3 (T4/T3) ratio. In the hypothalamus-pituitary dyad as well as the rest of the brain, the majority of T3 present is generated locally by T4 deiodination via the type 2 deiodinase (D2); this pathway is self-limited by ubiquitination of D2 by the ubiquitin ligase WSB-1. Here, we determined that tissue-specific differences in D2 ubiquitination account for the high T4/T3 serum ratio in adult thyroidectomized (Tx) rats chronically implanted with subcutaneous L-T4 pellets. While L-T4 administration decreased whole-body D2-dependent T4 conversion to T3, D2 activity in the hypothalamus was only minimally affected by L-T4. In vivo studies in mice harboring an astrocyte-specific Wsb1 deletion as well as in vitro analysis of D2 ubiquitination driven by different tissue extracts indicated that D2 ubiquitination in the hypothalamus is relatively less. As a result, in contrast to other D2-expressing tissues, the hypothalamus is wired to have increased sensitivity to T4. These studies reveal that tissue-specific differences in D2 ubiquitination are an inherent property of the TRH/TSH feedback mechanism and indicate that only constant delivery of L-T4 and L-T3 fully normalizes T3-dependent metabolic markers and gene expression profiles in Tx rats.

[Comparison of basic carboxypeptidases activity in male rats tissues at a single injection of haloperidol].

The influence of a single injection of haloperidol on basic carboxypeptidases (biologically active peptide processing enzymes) activity in rat tissues was studied. Acute exposure to haloperidol increased the activity of carboxypeptidases H (CP H) in hypothalamic-pituitary-adrenal system and cerebellum and reduced such activity in testes. Multidirectional changes of PMSF-inhibited carboxypeptidases activity (PMSF-CP) were observed after a single haloperidol injection in all studied tissues except testes. It is suggested that changes of CP H and PMSF-CP activity might affect levels of regulatory peptides in the brain and blood and thus may be involved in general and side effects of haloperidol on the organism.

The role of DNA methylation in stress-related psychiatric disorders.

Epigenetic modifications in response to traumatic experience and stress are emerging as important factors in the long-term biological trajectories leading to stress-related psychiatric disorders, reflecting both environmental influences as well as individual genetic predisposition. In particular, recent evidence on DNA methylation changes within distinct genes and pathways but also on a genome-wide level provides new insights into the pathophysiology of stress related psychiatric disorders. This review summarizes current findings and concepts on DNA methylation changes in stress-related disorders with a focus on major depressive disorder and posttraumatic stress disorder (PTSD). We highlight studies of DNA methylation in animals and humans pertinent to these disorders, both focusing on candidate loci as well as genome-wide studies. We describe molecular mechanisms of how exposure to stress can induce long lasting changes in DNA methylation and how these may relate to the pathophysiology of depression and PTSD. We discuss data suggesting that DNA methylation, even in peripheral tissues, appears to be an informative reflection of environmental exposures on the genome and may have potential as a biomarker for the early prevention of stress-related disorders.

Developing predictive approaches to characterize adaptive responses of the reproductive endocrine axis to aromatase inhibition: II. Computational modeling.

Endocrine-disrupting chemicals can affect reproduction and development in humans and wildlife. We developed a computational model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course (DRTC) behaviors for endocrine effects of the aromatase inhibitor, fadrozole (FAD). The model describes adaptive responses to endocrine stress involving regulated secretion of a generic gonadotropin (LH/FSH) from the hypothalamic-pituitary complex. For model development, we used plasma 17ß-estradiol (E2) concentrations and ovarian cytochrome P450 (CYP) 19A aromatase mRNA data from two time-course experiments, each of which included both an exposure and a depuration phase, and plasma E2 data from a third 4-day study. Model parameters were estimated using E2 concentrations for 0, 0.5, and 3 µg/l FAD exposure concentrations, and good fits to these data were obtained. The model accurately predicted CYP19A mRNA fold changes for controls and three FAD doses (0, 0.5, and 3 µg/l) and plasma E2 dose response from the 4-day study. Comparing the model-predicted DRTC with experimental data provided insight into how the feedback control mechanisms in the HPG axis mediate these changes: specifically, adaptive changes in plasma E2 levels occurring during exposure and "overshoot" occurring postexposure. This study demonstrates the value of mechanistic modeling to examine and predict dynamic behaviors in perturbed systems. As this work progresses, we will obtain a refined understanding of how adaptive responses within the vertebrate HPG axis affect DRTC behaviors for aromatase inhibitors and other types of endocrine-active chemicals and apply that knowledge in support of risk assessments.

Developing predictive approaches to characterize adaptive responses of the reproductive endocrine axis to aromatase inhibition: I. Data generation in a small fish model.

Adaptive or compensatory responses to chemical exposure can significantly influence in vivo concentration-duration-response relationships. This study provided data to support development of a computational dynamic model of the hypothalamic-pituitary-gonadal axis of a model vertebrate and its response to aromatase inhibitors as a class of endocrine active chemicals. Fathead minnows (Pimephales promelas) were either exposed to the aromatase inhibitor fadrozole (0.5 or 30 µg/l) continuously for 1, 8, 12, 16, 20, 24, or 28 days or exposed for 8 days and then held in control water (no fadrozole) for an additional 4, 8, 12, 16, or 20 days. The time course of effects on ovarian steroid production, circulating 17ß-estradiol (E2) and vitellogenin (VTG) concentrations, and expression of steroidogenesis-related genes in the ovary was measured. Exposure to 30 µg fadrozole/l significantly reduced plasma E2 and VTG concentrations after just 1 day and those effects persisted throughout 28 days of exposure. In contrast, ex vivo E2 production was similar to that of controls on day 8-28 of exposure, whereas transcripts coding for aromatase and follicle-stimulating hormone receptor were elevated, suggesting a compensatory response. Following cessation of fadrozole exposure, ex vivo E2 and plasma E2 concentrations exceeded and then recovered to control levels, but plasma VTG concentrations did not, even after 20 days of depuration. Collectively these data provide several new insights into the nature and time course of adaptive responses to an aromatase inhibitor that support development of a computational model (see companion article).

The role of the nervous system in the regulation of liver cytochrome p450.

The central and peripheral nervous systems are important factors influencing the functioning of liver cytochrome P450 (CYP). It has been shown that changes in the brain monoaminergic systems affect liver cytochrome P450 (CYP) expression (CYP1A, CYP2B, CYP2C11 and CYP3A). The brain dopaminergic system has been established as an important center regulating the liver CYP. This regulation proceeds via the tuberoinfundibular pathway and the dopaminergic D2 receptors of the pituitary, as well as the mesolimbic pathway engaging the D2 receptors of the nucleus accumbens (conveying a message to the paraventricular nucleus of the hypothalamus). These two dopaminergic pathways stimulate the secretion of pituitary hormones, which directly (GH) or indirectly (ACTH, TSH) activate hepatic nuclear/ cytosolic receptors controlling CYP genes. Recent preliminary studies with selective noradrenaline or serotonin neurotoxins suggest also involvement of the brain noradrenergic and serotonergic systems in the regulation of liver CYP. Moreover, the influence of the peripheral nervous system involving several neurotransmitters (acetylcholine, noradrenaline, adrenaline, dopamine, serotonin) on liver function may also be important for the physiological regulation of hepatic CYP activity. The hypothalamus controls liver function not only by releasing hormones from the pituitary gland but also by stimulating the autonomic sympathetic and parasympathetic projections to the liver. In addition to direct neural connections, the autonomic nervous system can indirectly affect liver function via the hypothalamus-adrenal axis and the hypothalamus- pancreas axis. Therefore, the estimation of neuroactive drug action on hepatic CYP requires an in vivo model which allows the central neuroendocrine and peripheral autonomic regulation of genes coding for CYP isoforms.

Effect of hyperosmotic stress on the gene expression and activity of neuronal nitric oxide synthase (nNOS) in the preoptic-hypothalamic neurosecretory system of the euryhaline fish Oreochromis mossambicus.

We examined the effects of hyperosmotic stress on the gene expression and activity of neuronal nitric oxide synthase (nNOS) in the preoptic/hypothalamic neurosecretory system of the euryhaline tilapia Oreochromis mossambicus (Mozambique tilapia) by means of semiquantitative RT-PCR and NADPHd histochemistry. Expression of nos1 was rapidly and transiently up-regulated in the preoptic region and hypothalamus in response to a salinity change (70% seawater, SW). Expression levels increased 4 h after the salinity change and then returned to basal levels within 8 h of the hyperosmotic challenge. NADPHd histochemistry revealed that positive magnocellular and gigantocellular preoptic neurons increased in number 4 h after the salinity change, while the number of parvocellular preoptic neurons reactive for NADPHd showed no significant change. These results indicate that the nNOS gene expression and NOS activity are stimulated in the preoptic/ hypothalamic neurosecretory system in response to hyperosmotic stress and suggest that NO influences neuronal responses to short-term osmotic stimulation in euryhaline fish.

Immunology, signal transduction, and behavior in hypothalamic-pituitary-adrenal axis-related genetic mouse models.

A classical view of the neuroendocrine-immune network assumes bidirectional interactions where pro-inflammatory cytokines influence hypothalamic-pituitary-adrenal (HPA) axis-derived hormones that subsequently affect cytokines in a permanently servo-controlled circle. Nevertheless, this picture has been continuously evolving over the last years as a result of the discovery of redundant expression and extended functions of many of the molecules implicated. Thus, cytokines are not only expressed in cells of the immune system but also in the central nervous system, and many hormones present at hypothalamic-pituitary level are also functionally expressed in the brain as well as in other peripheral organs, including immune cells. Because of this intermingled network of molecules redundantly expressed, the elucidation of the unique roles of HPA axis-related molecules at every level of complexity is one of the major challenges in the field. Genetic engineering in the mouse offers the most convincing method for dissecting in vivo the specific roles of distinct molecules acting in complex networks. Thus, various immunological, behavioral, and signal transduction studies performed with different HPA axis-related mutant mouse lines to delineate the roles of beta-endorphin, the type 1 receptor of corticotropin-releasing hormone (CRHR1), and its ligand CRH will be discussed here.

Inducible prostaglandin E2 synthesis interacts in a temporally supplementary sequence with constitutive prostaglandin-synthesizing enzymes in creating the hypothalamic-pituitary-adrenal axis response to immune challenge.

Inflammation-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis has been suggested to depend on prostaglandins, but the prostaglandin species and the prostaglandin-synthesizing enzymes that are responsible have not been fully identified. Here, we examined HPA axis activation in mice after genetic deletion or pharmacological inhibition of prostaglandin E(2)-synthesizing enzymes, including cyclooxygenase-1 (Cox-1), Cox-2, and microsomal prostaglandin E synthase-1 (mPGES-1). After immune challenge by intraperitoneal injection of lipopolysaccharide, the rapid stress hormone responses were intact after Cox-2 inhibition and unaffected by mPGES-1 deletion, whereas unselective Cox inhibition blunted these responses, implying the involvement of Cox-1. However, mPGES-1-deficient mice showed attenuated transcriptional activation of corticotropin-releasing hormone (CRH) that was followed by attenuated plasma concentrations of adrenocorticotropic hormone and corticosterone. Cox-2 inhibition similarly blunted the delayed corticosterone response and further attenuated corticosterone release in mPGES-1 knock-out mice. The expression of the c-fos gene, an index of synaptic activation, was maintained in the paraventricular hypothalamic nucleus and its brainstem afferents both after unselective and Cox-2 selective inhibition as well as in Cox-1, Cox-2, and mPGES-1 knock-out mice. These findings point to a mechanism by which (1) neuronal afferent signaling via brainstem autonomic relay nuclei and downstream Cox-1-dependent prostaglandin release and (2) humoral, CRH transcription-dependent signaling through induced Cox-2 and mPGES-1 elicited PGE(2) synthesis, shown to occur in brain vascular cells, play distinct, but temporally supplementary roles for the stress hormone response to inflammation.

Cyp11b1 null mouse, a model of congenital adrenal hyperplasia.

Patients with congenital adrenal hyperplasia arising from mutations of 11beta-hydroxylase, the final enzyme in the glucocorticoid biosynthetic pathway, exhibit glucocorticoid deficiency, adrenal hyperplasia driven by unsuppressed hypothalamo-pituitary-adrenal activity, and excess mineralocorticoid activity caused by the accumulation of deoxycorticosterone. A mouse model, in which exons 3-7 of Cyp11b1 (the gene encoding 11beta-hydroxylase) were replaced with cDNA encoding enhanced cyan fluorescent protein, was generated to investigate the underlying disease mechanisms. Enhanced cyan fluorescent protein was expressed appropriately in the zona fasciculata of the adrenal gland, and targeted knock-out was confirmed by urinary steroid profiles and, immunocytochemically, by the absence of 11beta-hydroxylase. The null mice exhibited glucocorticoid deficiency, mineralocorticoid excess, adrenal hyperplasia, mild hypertension, and hypokalemia. They also displayed glucose intolerance. Because rodents do not synthesize adrenal androgens, changes in reproductive function such as genital virilization of females were not anticipated. However, adult homozygote females were infertile, their ovaries showing an absence of corpora lutea and a central proliferation of disorganized steroidogenic tissue. Null females responded normally to superovulation, suggesting that raised systemic progesterone levels also contribute to infertility problems. The model reveals previously unrecognized phenotypic subtleties of congenital adrenal hyperplasia.

[Diencephalo-telencephalic changes of tyrosine hydroxylase in rats and common frogs (Rana temporaria) after sleep deprivation].

Based on sleep deprivation-produced changes of electrographic parameters of the wakefulness--sleep cycle (WSC) in rats and common frogs, dynamics of activity of tyrosine hydroxylase, the key enzyme of dopamine synthesis, was studied immunohistochemically in substantia nigra and nigrostriatal pathway in rats and in striatum, paraventricular organ, and extrahypothalamic pathways in frogs. There are revealed changes in dynamics of tyrosine hydroxylase in rats and in common frogs after the 6-h sleep deprivation and after 2 h of postdeprivation sleep. This allows determining the degree of participation of corticostriatal neuroregulatory and hypothalamo-pituitary neurosecretory systems and their role in regulation of WSC. Possible evolutionary peculiarities of morphofunctional differences in homoiothermal and poikilothermal animals are discussed.

Tissue-specific programming expression of glucocorticoid receptors and 11 beta-HSDs by maternal perinatal undernutrition in the HPA axis of adult male rats.

Maternal undernutrition leads to intrauterine growth retardation and predisposes to the development of pathologies in adulthood. The hypothalamo-pituitary-adrenal axis is a major target of early-life programming. We showed previously that perinatal maternal 50% food restriction leads to hypothalamo-pituitary-adrenal axis hyperactivity and disturbs glucocorticoid feedback in adult male rats. To try to better understand these alterations, we studied several factors involved in corticosterone sensitivity. We showed that unlike the restricted expression of 11 beta-HSD2 mRNA, the 11 beta-HSD1, glucocorticoid, and mineralocorticoid receptor genes are widely distributed in rat. In contrast to the hypothalamus, we confirmed that maternal undernutrition modulates hippocampal corticosterone receptor balance and leads to increased 11 beta-HSD1 gene expression. In the pituitary, rats exhibited a huge increase in both mRNA and mineralocorticoid receptor binding capacities as well as decreased 11 beta-HSD1/11 beta-HSD2 gene expression. Using IN SITU hybridization, we showed that the mineralocorticoid receptor gene was expressed in rat corticotroph cells and by other adenopituitary cells. In the adrenal gland, maternal food restriction decreased 11beta-HSD2 mRNA. This study demonstrated that maternal food restriction has both long-term and tissue-specific effects on gene expression of factors involved in glucocorticoid sensitivity and that it could contribute, via glucocorticoid excess, to the development of adult diseases.