References of "Foidart, Agnès"
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See detailCdk2 Is Dispensable for Adult Hippocampal Neurogenesis
Vandenbosch, Renaud ULg; Borgs, Laurence ULg; Beukelaers, Pierre ULg et al

in Cell Cycle (Georgetown, Tex.) (2007), 6(24), 3065-9

Granule neurons of the dentate gyrus (DG) of the hippocampus undergo continuous renewal throughout life. Among cell cycle regulators, cyclin-dependent kinase 2 (Cdk2) is considered as a major regulator of ... [more ▼]

Granule neurons of the dentate gyrus (DG) of the hippocampus undergo continuous renewal throughout life. Among cell cycle regulators, cyclin-dependent kinase 2 (Cdk2) is considered as a major regulator of S-phase entry. We used Cdk2-deficient mice to decipher the requirement of Cdk2 for the generation of new neurons in the adult hippocampus. The quantification of cell cycle markers first revealed that the lack of Cdk2 activity does not influence spontaneous or seizure-induced proliferation of neural progenitor cells (NPC) in the adult DG. Using bromodeoxyuridine incorporation assays, we showed that the number of mature newborn granule neurons generated de novo was similar in both wild-type (WT) and Cdk2-deficient adult mice. Moreover, the apparent lack of cell output reduction in Cdk2(-/-) mice DG did not result from a reduction in apoptosis of newborn granule cells as analyzed by TUNEL assays. Our results therefore suggest that Cdk2 is dispensable for NPC proliferation, differentiation and survival of adult-born DG granule neurons in vivo. These data emphasize that functional redundancies between Cdks also occur in the adult brain at the level of neural progenitor cell cycle regulation during hippocampal neurogenesis. [less ▲]

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See detailCharacterization of the neurotoxicity induced by the extract of Magnistipula butayei (Chrysobalanaceae) in rat: Effects of a new natural convulsive agent
Karangwa, Charles; Esters, Virginie ULg; Tits, Monique ULg et al

in Toxicon (2007), 49(8), 1109-1119

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system ... [more ▼]

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system in these effects. Continuous behavioral observations and electroencephalographic (EEG) records were obtained after per os administration of an aqueous extract of Magnistipula (MBMAE) in rats. MBMAE (800 mg/kg) induced behavioral changes resembling motor limbic seizures: staring and head tremor, automatisms, forelimb clonic movements and violent tonic-clonic seizures leading to death in all animals. Concomitantly, important seizure activity that gradually evolved to epileptiform activity was recorded on the EEG. Moreover, c-Fos immunohistochemistry has revealed an increased c-Fos expression in the dentate gyrus and in piriform, peri- and entorhinal cortices 2 and 4h after treatment. This expression pattern suggested that the mechanism of action for the MBMAE is similar to that observed in glutamate-induced models of epilepsy. The MBMAE increased cell death also in hippocampal cell cultures. Furthermore, the build-up of convulsive activity and epileptic discharges induced by MBMAE in rat were abolished by MK-801, an NMDA receptor antagonist. Our study suggests that MBMAE contains a potent toxin, with a powerful neurotoxic activity in rat, and corresponding to a new natural component(s) that act as an NMDA-mediated convulsant molecule. [less ▲]

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See detailMice lacking the melanin-concentrating hormone receptor-1 exhibit an atypical psychomotor susceptibility to cocaine and no conditioned cocaine response
Tyhon, Alain ULg; Adamantidis, Antoine ULg; Foidart, Agnès ULg et al

in Behavioural Brain Research (2006), 173(1), 94-103

The present study aimed at characterizing the acute and intermittent psychomotor responsiveness to cocaine in mice lacking the MCHR1 receptor, which is thought to modulate the mesocorticolimbic sytem ... [more ▼]

The present study aimed at characterizing the acute and intermittent psychomotor responsiveness to cocaine in mice lacking the MCHR1 receptor, which is thought to modulate the mesocorticolimbic sytem functioning [Smith DG, Tzavara ET, Shaw J, Luecke S, Wade M, Davis R, et al. Mesolimbic dopamine super-sensitivity in melanin-concentrating hormone-1 receptor deficient mice. J Neurosci 2005;25:914-22]. On a first free-drug session, MCHR1-deficient mice exhibited significantly higher levels of locomotor activity elicited by the novelty of the test chambers than their wild-type counterparts. On the following day session, a first injection of 6 or 12mg/kg cocaine induced comparable dose-related psychomotor activations in both genotypes, without significant difference in the relative increase in locomotion. Over the following eight once-daily test sessions, the slight psychomotor increase induced by 6mg/kg was equivalent in both genotypes and constant over the sessions. At 12mg/kg, cocaine induced a clear-cut incremental responsiveness to cocaine in both genotypes on the three first sessions; on the following sessions, only the wild-types displayed an incremental responsiveness until the last session, a sensitized effect that was confirmed for the wild-types but not for the knockouts on a subsequent sensitization test (cocaine challenge). Finally, the knockouts did not exhibit any sign of cocaine-conditioning (saline challenge), contrarily to the wild-types. It is speculated that MCHR1 may contribute to the neurobiological mechanisms of conditioned cocaine-induced psychomotor effects, possibly to those underpinning sensitization, and to a lesser extent to those sub-serving acute pharmacological cocaine action. [less ▲]

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See detailEffects of vagal nerve stimulation in the rat orofacial formalin model of pain
Multon, Sylvie ULg; Scholsem, Martin; LEGRAIN, Caroline ULg et al

in Book of Abstracts of the 36th Annual Meeting Society for Neuroscience (Oct 2006) (2006, October)

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See detailSome genetic and biochemical aspects of myoclonus
Grisar, Thierry ULg; de Nijs, Laurence ULg; Chanas, G. et al

in Neurophysiologie Clinique = Clinical Neurophysiology (2006), 36(5-6, Sep-Dec), 271-279

Can a gene defect be responsible for the occurrence in an individual, at a particular age, of such a muscle twitch followed by relaxation called: "myoclonus" and defined as sudden, brief, shock-like ... [more ▼]

Can a gene defect be responsible for the occurrence in an individual, at a particular age, of such a muscle twitch followed by relaxation called: "myoclonus" and defined as sudden, brief, shock-like movements? Genetic defects could indeed determine a subsequent cascade of molecular events (caused by abnormal encoded proteins) that would produce new aberrant cellular relationships in a particular area of the CNS leading to re-builded "myoclonogenic" neuronal networks. This can be illustrated reviewing some inherited neurological entities that are characterized by a predominant myoclonic picture and among which a clear gene defect has been identified. In the second part of this chapter, we will also propose a new point of view on how some structural genes could, under certain conditions, when altered, produced idiopathic generalized epilepsy with myoclonic jerks, taking juvenile myoclonic epilepsy (JME) and the myoclonin (EFHC-1) gene as examples. (c) 2007 Elsevier Masson SAS. All rights reserved. [less ▲]

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See detailDisrupting the melanin-concentrating hormone receptor 1 in mice leads to cognitive and NMDA response deficit
Grisar, Thierry ULg; Adamantidis, Antoine ULg; Thomas, Elizabeth et al

in Journal of the Neurological Sciences (2005, November 15), 238(Suppl. 1), 288

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See detailDisrupting the melanin-concentrating hormone receptor 1 in mice leads to cognitive deficits and alterations of NMDA receptor function.
Adamantidis, Antoine ULg; Thomas, Elizabeth; Foidart, Agnès ULg et al

in European Journal of Neuroscience (2005), 21(10), 2837-44

In order to investigate the physiological properties of the melanin-concentrating hormone (MCH) we have generated and used mice from which the MCH receptor 1 gene was deleted (MCHR1(Neo/Neo) mice ... [more ▼]

In order to investigate the physiological properties of the melanin-concentrating hormone (MCH) we have generated and used mice from which the MCH receptor 1 gene was deleted (MCHR1(Neo/Neo) mice). Complementary experimental approaches were used to investigate alterations in the learning and memory processes of our transgenic model. The ability of the knockout strain to carry out the inhibitory passive avoidance test was found to be considerably impaired although no significant differences were observed in anxiety levels. This impaired cognitive property prompted us to explore modifications in N-methyl D-aspartate (NMDA) responses in the hippocampus. Intracellular recordings of CA1 pyramidal neurons in hippocampal slices from the MCHR1(Neo/Neo) mice revealed significantly decreased NMDA responses. Finally, using in situ hybridization we found a 15% reduction in NMDAR1 subunit in the CA1 region. These results show for the first time a possible role for MCH in the control of the function of the NMDA receptor. [less ▲]

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See detailLocalization and Controls of Aromatase in the Quail Spinal Cord
Evrard, H.; Baillien, M.; Foidart, Agnès ULg et al

in Journal of Comparative Neurology (The) (2000), 423(4), 552-64

In adult male and female Japanese quail, aromatase-immunoreactive cells were identified in the spinal dorsal horns from the upper cervical segments to the lower caudal area. These immunoreactive cells are ... [more ▼]

In adult male and female Japanese quail, aromatase-immunoreactive cells were identified in the spinal dorsal horns from the upper cervical segments to the lower caudal area. These immunoreactive cells are located mostly in laminae I-III, with additional sparse cells being present in the medial part of lamina V and, at the cervical level exclusively, in lamina X around the central canal. Radioenzyme assays based on the measurement of tritiated water release confirmed the presence of substantial levels of aromatase activity throughout the rostrocaudal extent of the spinal cord. Contrary to what is observed in the brain, this enzyme activity and the number of aromatase-immunoreactive cells in five representative segments of the spinal cord are not different in sexually mature males or females and are not influenced in males by castration with or without testosterone treatment. The aromatase activity and the numbers of aromatase-immunoreactive cells per section are higher at the brachial and thoracic levels than in the cervical and lumbar segments. These experiments demonstrate for the first time the presence of local estrogen production in the spinal cord of a higher vertebrate. This production was localized in the sensory fields of the dorsal horn, where estrogen receptors have been identified previously in several avian and mammalian species, suggesting an implication of aromatase in the modulation of sensory (particularly nociceptive) processes. [less ▲]

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See detailImmunocytochemical localization of ionotropic glutamate receptors subunits in the adult quail forebrain
Cornil, Charlotte ULg; Foidart, Agnès ULg; Minet, Arlette ULg et al

in Journal of Comparative Neurology (The) (2000), 428

The excitatory amino acid glutamate is implicated in the central control of many neuroendocrine and behavioral processes. The ionotropic glutamate receptors are usually divided into the N-methyl-D ... [more ▼]

The excitatory amino acid glutamate is implicated in the central control of many neuroendocrine and behavioral processes. The ionotropic glutamate receptors are usually divided into the N-methyl-D-aspartate (NMDA) and non-NMDA (kainate and AMPA) subtypes. Subunits of these receptors have been cloned in a few mammalian species. Information available in birds is more limited. In quail, we recently demonstrated that glutamate agonists (kainate, AMPA, and NMDA) rapidly (within minutes) and reversibly decrease in vitro aromatase activity like several other manipulations affecting intracellular HCa21 pools. Aromatase catalyzes the conversion of androgens into estrogens which is a limiting step in the control by testosterone of many behavioral and physiologic processes. Therefore, glutamate could control estrogen production in the brain, but the anatomic substrate supporting this effect is poorly understood. In quail, aromatase is mainly localized in the preoptic-hypothalamic-limbic system. We visualized here the distribution of the major ionotropic glutamate receptors in quail by immunocytochemical methods by using commercial primary antibodies raised against rat glutamate receptor 1 and receptors 2-3 (GluR1, GluR2/3: AMPA subtype, Chemicon, CA), rat glutamate receptors 5-7 (GluR5-7: kainate subtype, Pharmingen, CA), and rat NMDA receptors (NMDAR1, Pharmingen, CA). Dense and specific signals were obtained with all antibodies. The four types of receptors are broadly distributed in the brain, and, in particular, immunoreactive cells are identified within the major aromatase cell groups located in the medial preoptic nucleus, ventromedial hypothalamus, nucleus striae terminalis, and nucleus taeniae. Dense specific populations of glutamate receptor immunoreactive cells are also present with a receptor subtype-specific distribution in broad areas of the telencephalon. The distribution of glutamate receptors, therefore, is consistent with the idea that these receptors could be located at the surface of aromatase-containing cells and mediate the rapid regulation of aromatase activity in a direct manner. [less ▲]

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See detailEstrogen Receptor-Beta in Quail: Cloning, Tissue Expression and Neuroanatomical Distribution
Foidart, Agnès ULg; Lakaye, Bernard ULg; Grisar, Thierry ULg et al

in Journal of Neurobiology (1999), 40(3), 327-42

A partial estrogen receptor-beta (ERbeta) cDNA had been previously cloned and sequenced in Japanese quail. The 3'- and 5'-rapid amplification of cDNA ends techniques were used here to identify a cDNA ... [more ▼]

A partial estrogen receptor-beta (ERbeta) cDNA had been previously cloned and sequenced in Japanese quail. The 3'- and 5'-rapid amplification of cDNA ends techniques were used here to identify a cDNA sequence of the quail ERbeta that contains a complete open reading frame. For the first time in an avian species, this cDNA sequence and the corresponding amino acid sequence are described. They are compared with the known ERbeta sequences previously described in mammals and with the ERalpha sequences identified in a selection of mammalian and avian species. The analysis by Northern blotting of the ERbeta mRNA expression in the brain and kidneys revealed the presence of several transcripts. The presence of ERbeta identified by reverse transcriptase-polymerase chain reaction demonstrated a widespread distribution quite different from the distribution of ERalpha. The complete neuroanatomical distribution of ERbeta mRNA as determined by in situ hybridization with 35S- and 33P-labeled oligoprobes is also presented. Transcripts are present in many nuclei implicated in the control of reproduction such as the medial preoptic nucleus, the nucleus striae terminalis, and the nucleus taeniae, the avian homologue of the amygdala. These data demonstrate the presence of ERbeta in a nonmammalian species and indicate that the (neuro)-anatomical distribution of this receptor type has been conserved in these two classes of vertebrates. The role of this receptor in the control of reproduction and other physiological processes should now be investigated. [less ▲]

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See detailMating-Induced Fos and Aromatase Are Not Co-Localized in the Preoptic Area
Foidart, Agnès ULg; Meddle, S. L.; Balthazart, Jacques ULg

in Neuroreport (1999), 10(5), 907-12

Male sexual behavior is determined by the interaction of endocrine and environmental stimuli originating from the female, yet it is unknown how and where these stimuli are integrated within the brain ... [more ▼]

Male sexual behavior is determined by the interaction of endocrine and environmental stimuli originating from the female, yet it is unknown how and where these stimuli are integrated within the brain. Activation of copulatory behavior by testosterone is limited by its central aromatization into an estrogen in the preoptic area. We investigated whether mating-induced neuronal activation as identified by the expression of the immediate early gene Fos occurs in aromatase-immunoreactive (ARO-ir) cells of the male quail preoptic area. Fos-immunoreactive (ir) cells were observed within and lateral to these ARO-ir cells groups but few ARO-ir cells contained Fos-ir indicating that mating-related stimuli do not directly affect estrogen-synthesizing cells. [less ▲]

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See detailRegional Distribution and Control of Tyrosine Hydroxylase Activity in the Quail Brain
Baillien, M.; Foidart, Agnès ULg; Balthazart, Jacques ULg

in Brain Research Bulletin (1999), 48(1), 3-17

Tyrosine hydroxylase (TH) activity, the rate-limiting step in the synthesis of catecholamines, was quantified in the preoptic area-hypothalamus of adult male Japanese quail by a new assay measuring the ... [more ▼]

Tyrosine hydroxylase (TH) activity, the rate-limiting step in the synthesis of catecholamines, was quantified in the preoptic area-hypothalamus of adult male Japanese quail by a new assay measuring the tritiated water production from 3,5-[3H]-L-tyrosine. Maximal levels of activity were observed at a 20-25 microM concentration of substrate, with more than 50% inhibition of the activity being recorded at a 100 microM concentration. TH activity was linear as a function of the incubation time during the first 20 min and maximal at a pH of 6.0. TH was heterogeneously distributed in the quail brain with highest levels of activity being found (in decreasing order) in the mesencephalon, diencephalon, and telencephalon. Given the large size of the telencephalon, this is the brain area that contains, as a whole, the highest level of enzyme activity. TH inhibitors that have been well-characterized in mammals, such as 3-iodo-L-tyrosine and L-alpha-methyl-p-tyrosine (AMPT) completely inhibited the enzyme activity at a 100 microM concentration. In mammals, the accumulation of catecholamines exerts a negative feedback control on TH activity. Similar controls were observed in the quail brain. Two inhibitors of the DOPA decarboxylase that should lead to accumulation of DOPA depressed TH activity by 60% or more, and the inhibitor of the dopamine beta-hydroxylase, fusaric acid that should cause an accumulation of dopamine, suppressed 90% of the TH activity. The addition of exogenous DOPA, dopamine, or norepinephrine to the brain homogenates also strongly inhibited TH activity, independently confirming the feedback effects of the enzyme products on the enzyme activity. These data demonstrate that TH activity in the quail brain is heterogeneously distributed and acutely regulated, as it is in mammals, by the accumulation of its products and of the derived catecholamines. [less ▲]

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See detailSteroid sensitive sites in the avian brain: does the distribution of the estrogen receptor alpha and beta types provide insight into their function?
Ball, G. F.; Bernard, D. J.; Foidart, Agnès ULg et al

in Brain, Behavior & Evolution (1999), 54

Studies in avian species have often been useful in elucidating basic concepts relevant to the regulation of reproductive behaviors by sex steroid hormones. Once a link between a steroid hormone and a ... [more ▼]

Studies in avian species have often been useful in elucidating basic concepts relevant to the regulation of reproductive behaviors by sex steroid hormones. Once a link between a steroid hormone and a behavioral response has been established, one can use the localization of steroid hormone receptors in the brain to facilitate the identification of neural circuits that control behavior. The recent identification of a second type of estrogen receptor called estrogen receptor beta or ERbeta has raised new issues about the action of steroid hormones in the brain. A hypothesis has been proposed by Kuiper et al. [1998] based on studies in mammalian species suggesting that ERalpha (the name given to the ER that was previously described) is important for reproduction while ERbeta is more important for non-reproductive functions. In this paper we apply this hypothesis more generally by examining possible functions of ERbeta in avian species. We have initiated studies of the ERbeta in the brain of two avian species, the Japanese quail (Coturnix japonica) and the European starling (Sturnus vulgaris). ERbeta was cloned in both species and the mRNA for this receptor type was localized in the brain employing in situ hybridization histochemistry methods. In both species ERbeta was found to be diffusely present in telencephalic areas consistent with a role for this receptor subtype in cognitive functions. However, ERbeta mRNA was also found in many brain areas that are traditionally thought to be important in the regulation of reproductive functions such as the preoptic region, the bed nucleus of the stria terminalis and the nucleus taeniae. Of the two receptor types, only mRNA for ERalpha was observed in the telencephalic vocal control nucleus HVc of male starlings. Steroid receptors in this nucleus are thought to be an example of an evolutionary specialization that has evolved to coordinate the production of courtship vocalizations with other aspects of reproduction. The lack of ERbeta mRNA expression in HVc is consistent with the hypothesis that ERalpha is preferentially involved in reproductive behaviors while ERbeta is involved in the steroid regulation of other neural functions. However, the widespread occurrence of ERbeta in other nuclei involved in reproductive function suggests that one must be cautious about the general applicability of the above hypothesis until more is known about ERbeta function in these other nuclei [less ▲]

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See detailPartial Cloning and Distribution of Estrogen Receptor Beta in the Avian Brain
Lakaye, Bernard ULg; Foidart, Agnès ULg; Grisar, Thierry ULg et al

in Neuroreport (1998), 9(12), 2743-8

A partial estrogen receptor beta (ER-beta) cDNA was isolated from testicular quail RNA by RT-PCR with degenerate primers specific to the rat ER-beta sequence. A high expression of ER-beta was demonstrated ... [more ▼]

A partial estrogen receptor beta (ER-beta) cDNA was isolated from testicular quail RNA by RT-PCR with degenerate primers specific to the rat ER-beta sequence. A high expression of ER-beta was demonstrated by RT-PCR in the telencephalon, diencephalon, pituitary, testis and kidneys of male quail but little or no expression was detected in the cerebellum, pectoral muscle and adrenal gland. In situ hybridization with a 35S-labelled oligoprobe in sections through the preoptic area-rostral hypothalamus identified high expression in the medial preoptic nucleus, bed nucleus striae terminalis and nucleus taeniae. These data demonstrate the presence of an ER-beta in brain areas implicated in the control of reproduction in a non-mammalian species. [less ▲]

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See detailDistribution of Androgen Receptor-Immunoreactive Cells in the Quail Forebrain and Their Relationship with Aromatase Immunoreactivity
Balthazart, Jacques ULg; Foidart, Agnès ULg; Houbart, M. et al

in Journal of Neurobiology (1998), 35(3), 323-40

The distribution of androgen receptor-like immunoreactive (AR-ir) cells in the quail brain was analyzed by immunocytochemistry with the use of the affinity-purified antibody PG-21-19A raised against a ... [more ▼]

The distribution of androgen receptor-like immunoreactive (AR-ir) cells in the quail brain was analyzed by immunocytochemistry with the use of the affinity-purified antibody PG-21-19A raised against a synthetic peptide representing the first 21 N-terminal amino acids of the rat and human AR. This antibody is known to bind to the receptor in the absence as well as in the presence of endogenous ligands, and it was therefore expected that a more complete and accurate characterization of AR-ir cells would be obtained in comparison with previous studies using an antibody that preferentially recognizes the occupied receptor. Selected sections were double labeled for aromatase (ARO) by a technique that uses alkaline phosphatase as the reporter enzyme and Fast blue as the chromogen. AR-ir material was detected in the nucleus of cells located in a variety of brain areas in the preoptic region and the hypothalamus including the medial preoptic (POM), the supraoptic, the paraventricular (PVN), and the ventromedial (VMN) nuclei, but also in the tuberculum olfactorium, the nucleus accumbens/ventral striatum, the nucleus taeniae, the tuberal hypothalamus, the substantia grisea centralis (GCt), and the locus ceruleus. Cells exhibiting a dense AR-ir label were also detected in the nucleus intercollicularis. Preincubation of the primary antibody with an excess of the synthetic peptide used for immunization completely eliminated this nuclear staining. A significant number of AR-ir cells in the POM, VMN, PVN, and tuberal hypothalamus also contained ARO-ir material in their cytoplasm. These data confirm and extend previous studies localizing AR in the avian brain, and raise questions about the possible regulation by androgens of the metabolizing enzyme aromatase. [less ▲]

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See detailNeuroanatomical Distribution and Variations across the Reproductive Cycle of Aromatase Activity and Aromatase-Immunoreactive Cells in the Pied Flycatcher (Ficedula Hypoleuca)
Foidart, Agnès ULg; Silverin, B.; Baillien, M. et al

in Hormones & Behavior (1998), 33(3), 180-96

The anatomical distribution and seasonal variations in aromatase activity and in the number of aromatase-immunoreactive cells were studied in the brain of free-living male pied flycatchers (Ficedula ... [more ▼]

The anatomical distribution and seasonal variations in aromatase activity and in the number of aromatase-immunoreactive cells were studied in the brain of free-living male pied flycatchers (Ficedula hypoleuca). A high aromatase activity was detected in the telencephalon and diencephalon but low to negligible levels were present in the optic lobes, cerebellum, and brain stem. In the diencephalon, most aromatase-immunoreactive cells were confined to three nuclei implicated in the control of reproductive behaviors: the medial preoptic nucleus, the nucleus of the stria terminalis, and the ventromedial nucleus of the hypothalamus. In the telencephalon, the immunopositive cells were clustered in the medial part of the neostriatum and in the hippocampus as previously described in another songbird species, the zebra finch. No immunoreactive cells could be observed in the song control nuclei. A marked drop in aromatase activity was detected in the anterior and posterior diencephalon in the early summer when the behavior of the birds had switched from defending a territory to helping the female in feeding the nestlings. This enzymatic change is presumably controlled by the drop in plasma testosterone levels observed at that stage of the reproductive cycle. No change in enzyme activity, however, was seen at that time in other brain areas. The number of aromatase-immunoreactive cells also decreased at that time in the caudal part of the medial preoptic nucleus but not in the ventromedial nucleus of the hypothalamus (an increase was even observed), suggesting that differential mechanisms control the enzyme concentration and enzyme activity in the hypothalamus. Taken together, these data suggest that changes in diencephalic aromatase activity contribute to the control of seasonal variations in reproductive behavior of male pied flycatchers but the role of the telencephalic aromatase in the control of behavior remains unclear at present. [less ▲]

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See detailAnatomical Relationships between Aromatase and Tyrosine Hydroxylase in the Quail Brain: Double-Label Immunocytochemical Studies
Balthazart, Jacques ULg; Foidart, Agnès ULg; Baillien, M. et al

in Journal of Comparative Neurology (The) (1998), 391(2), 214-26

The activation of male sexual behavior in Japanese quail (Coturnix japonica) requires the transformation of testosterone to 17beta-estradiol by the enzyme aromatase (estrogen synthetase). There are ... [more ▼]

The activation of male sexual behavior in Japanese quail (Coturnix japonica) requires the transformation of testosterone to 17beta-estradiol by the enzyme aromatase (estrogen synthetase). There are prominent sex differences in aromatase activity that may be regulated in part by sex differences in catecholaminergic activity. In this study, we investigate, with double-label immunocytochemistry methods, the anatomical relationship between the catecholamine synthesizing enzyme, tyrosine hydroxylase (TH) and aromatase (ARO) in the quail brain. The immunoreactivity observed for each antigen generally matched the previously described distribution. One exception is the observation that cells weakly labeled for aromatase were found widely distributed throughout the telencephalon. The presence of telencephalic aromatase was confirmed independently by radioenzymatic assays. There was an extensive overlap between the distribution of the two antigens in many brain areas. In all densely labeled aromatase-immunoreactive (ARO-ir) cell groups, including the preoptic medial nucleus, nucleus of the stria terminalis, mediobasal hypothalamus, and paleostriatum ventrale, ARO-ir cells were found in close association with TH-ir fibers. These TH-ir fibers often converged on an ARO-ir cell, and one or more TH-ir punctate structure(s) were found in close contact with nearly every densely labeled ARO-ir cell. In the telencephalon (mostly the neostriatum), all TH-ir fibers were found to be part of fiber groups that surrounded weakly immunoreactive aromatase cells. The few cells exhibiting an intracellular colocalization were detected in the anteroventral periventricular nucleus. These results are consistent with the hypothesis that catecholaminergic inputs regulate brain aromatase. [less ▲]

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See detailSystemic and Intracerebroventricular Injections of Vasotocin Inhibit Appetitive and Consummatory Components of Male Sexual Behavior in Japanese Quail
Castagna, C.; Absil, Philippe ULg; Foidart, Agnès ULg et al

in Behavioral Neuroscience (1998), 112(1), 233-50

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the ... [more ▼]

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. [less ▲]

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