A bazális előagyi kolinerg és GABAerg neuronpopulációk glutamáterg beidegzésének morfológiai elemzése = Morphological analyses of the glutamatergic innervation of cholinergic and GABAergic neuronal populations located in the rat basal forebrain cholinergic system

A basal forebrain (BFC) különböző régióiban a VGluT2 megjelenítésével glutamáterg idegrost-hálózatot mutattunk ki, mely aszimmetrikus kapcsolatokat képezett immunjelölt kolinerg, illetve GABAerg idegsejtekkel. Előfordultak VGluT2-immunarany plus ChAT-DAB-immunjelölt idegvégződések is szinaptikus kapcsolatban kolinerg neuronokkal. Glutamáterg szinapszisok nagyobb számban fordultak elő GABAerg mint kolinerg neuronokon, melyek kolinerg sejteken leggyakrabban dendrittörzseken, GABAerg neuronokon proximális dendritszakaszokon fordultak elő. Vizsgáltuk, hogy a BFC capsula internában lévő neuronok részt vesznek-e az entorhinalis kéreg (EC) afferentációban. Az EC-be injektált wheat germ agglutinin-gold retrográd transzport feltárta kolinerg, GABAerg és calretinint tartalmazó sejtek részvételét. [3H]D-aszpartátot alkalmazva kimutattuk, hogy az EC-hez vetítő kolinerg és CR-tartalmú neuronokban glutamát is van. - Megállapítottuk, hogy androgén receptort tartalmazó glutamáterg idegsejtek előfordulnak a septumban, bed nucleusban, hypothalmusban. Közöltük, hogy glutamáterg idegrostok végződnek GHRH neuronokon az arcuatusban, somastostatin tartalmú idegsejteken a nucleus periventricularis anteriorban, és VIP, AVP és GAD-ir neuronokon a nucleus suprachiasmaticusban. Felderítettük a táplálkozás és szexuális magatartás szabályozásában szerepet játszó nucleus ventromedialisban végződő glutamáterg rostok eredő sejtjeinek lokalizációját | We studied the glutamatergic innervation of cholinergic and GABAergic neurons in regions of the basal forebrain (BFC). Using vesicular glutamate transporter type2 (VGluT2) as marker of glutamatergic elements, we demonstrated numerous VGluT2 ir axon terminals in synaptic contact of the asymmetric type with cholinergic and GABAergic neurons. VGluT2 immungold plus DAB immunolabelled cholinergic nerve fibers terminating on dendrites of cholinergic neurons were also detected. There were more glutamatergic synapses on GABAergic than on cholinergic neurons. By means of retrograde transport of conjugated wheat germ agglutinin we observed that GABAergic and calretinin containing neurons in the BFC internal capsule project to the entorhinal cortex, and using [3H]D-asparte cholinergic and calretinin containing neurons terminating in the entorhinal cortex contain also glutamate. ? Further, we found glutamatergic neurons containing androgen receptor in the lateral septum, bed nucleus and in the hypothalamus. We published that glutamatergic fibres terminate on GHRH neurons in the arcuate, on somatostatin-ir nerve cells in the anterior periventricular and on VIP, AVP and GAD-ir neurons in the suprachiasmatic nucleus. Finally, we revealed by means of [3H]D-aspartate retrograde autoradiography the location of glutamatergic neurons projecting to the hypothalamic ventromedial nucleus involved in the control of feeding and sexual behaviour

Hypothalamikus struktúrák glutamáterg innervációjának neurokémiai és funkcionális elemzése = Glutamatergic innervation of hypothalamic structures: neurochemical and functional analysis

A [3H]D-aszpartát szelektív felvételén és retrográd transzportján alapuló autoradiográfiás eljárással feltérképeztük a mediális preoptikus areába projiciáló glutamáterg idegsejtek lokalizációját. Leírtuk, hogy vezikuláris glutamát transzporter immunreaktív idegvégződések, melyeket specifikus glutamáterg elemeknek lehet tekinteni, aszimmetrikus szinapszissal kapcsolódnak gonadotrop hormon-releasing hormon immunpozitív neuronokhoz a mediális preoptikus areában, neuropeptid Y, növekedési hormon-releasing hormon és pro-opiomelanocortin tartalmú idegsejtekhez a n. arcuatusban, szomatosztatinerg neuronokhoz a n. periventricularis anteriorban, valamint GABAerg, vazoaktív intesztinális polipeptidet és arginin-vazopresszint tartalmazó idegsejtekhez a n. suprachiasmaticusban. Kimutattuk, hogy nem-NMDA-receptor antagonista a n. paraventricularis hypothalamiba adva blokkolta a szopási inger valamint a formalin-stressz által kiváltott hypophysis prolaktin felszabadulást. | By means of the transmitter specific [3H]D-aspartate retrograde tracing technique we detected the location of glutamatergic neurons projecting to the medial preoptic area. We demonstrated synaptic contacts of the asymmetric type between vesicular glutamate transporter type 2 (selective marker of glutamatergic elements) nerve terminals and various neurons such as gonadotrop hormone-releasing hormone immunoreactive neurons in the medial preoptic area, neuropeptide Y, growth hormone-releasing hormone and pro-opiomelanocortin containing neurons in the arcuate nucleus, somatostatinerg nerve cells in the anterior periventricular nucleus and GABA, vasoactive intestinal polypeptide and arginine-vasopressin immunoreactive neurons in the suprachiasmatic nucleus. We observed that non-NMDA receptor antagonist injected into the hypothalamic paraventricular nucleus blocked the suckling stimulus-induced rise in plasma prolactin and the prolactin response to formalin stress

Stevia: beyond the sweetener

More and more people use sweeteners as sugar substitutes, and among these, one can find products of both natural and artificial origin. One of the most popular ones among natural sweeteners is Stevia of plant origin, and the popularity of the use of dried Stevia leaves as tea has been increasing as well. There are approximately 150 to 300 species that belong to the genus Stevia. Of these, the best known is Stevia rebaudiana Bertoni, and the sweetening power of the product, containing a mixture of glycosides, that can be obtained from its leaves, can be as high as 350 times of that of sugar. Before its authorization for use as a food additive in 2011, several evaluations were carried out regarding the safety of steviol glycosides, and finally an ADI value of 4 mg per kilograms of body weight was determined by the EFSA in 2010. Nonetheless, the Stevia rebaudiana Bertoni plant itself and its dried leaves are currently classified in the European Union as not authorized novel foods. This is so, because steviol glycosides authorized as sweeteners contain 95% purified stevioside and/or rebaudioside A, while dried Stevia leaves contain a variety of other components. Research into the risks of these are still taking place

Current State of Understanding of the Role of PACAP in the Hypothalamo-Hypophyseal Gonadotropin Functions of Mammals

PACAP was discovered 30 years ago in Dr. Akira Arimura's laboratory. In the past three decades since then, it has become evident that this peptide plays numerous crucial roles in mammalian organisms. The most important functions of PACAP are the following: 1. neurotransmitter, 2. neuromodulator, 3. hypophysiotropic hormone, 4. neuroprotector. This paper reviews the accumulated data regarding the distribution of PACAP and its receptors in the mammalian hypothalamus and pituitary gland, the role of PACAP in the gonadotropin hormone secretion of females and males. The review also summarizes the interaction between PACAP, GnRH, and sex steroids as well as hypothalamic peptides including kisspeptin. The possible role of PACAP in reproductive functions through the biological clock is also discussed. Finally, the significance of PACAP in the hypothalamo-hypophysial system is considered and the facts missing, that would help better understand the function of PACAP in this system, are also highlighted

Stevia: az édesítőszeren túl

Egyre többen használnak cukrot helyettesítő édesítőszereket, amelyek között találhatunk mind természetes, mind mesterséges eredetű termékeket. A természetes édesítőszerek között a növényi eredetű Stevia az egyik legkedveltebb, emellett a szárított Stevia levél teaként történő felhasználásának népszerűsége is nő. A Stevia nemzetségbe megközelítően 150-300 faj tartozik. Közülük a legismertebb a Stevia rebaudiana Bertoni, amelynek leveleiből kinyert glikozid keveréket tartalmazó termékek édesítő ereje 350-szerese is lehet a cukorénak. A 2011-es élelmiszer-adalékanyagként való engedélyezést megelőzően több értékelés is született a szteviolglikozidok biztonságosságára vonatkozóan, végül az EFSA 2010-ben 4 mg/ttkg ADI-értéket állapított meg. Maga a Stevia rebaudiana Bertoni növény és szárított levelei azonban ettől függetlenül az Európai Unióban jelenleg nem engedélyezett új élelmiszernek minősülnek. Az édesítőszerként engedélyezett szteviolglikozidok ugyanis 95%-ban tisztított szteviozidot és/vagy rebaudiozid A-t, míg a szárított Stevia levelek számos más komponenst is tartalmaznak. Ezek kockázataira irányuló kutatások jelenleg is zajlanak

The Same Magnocellular Neurons Send Axon Collaterals to the Posterior Pituitary and Retina or to the Posterior Pituitary and Autonomic Preganglionic Centers of the Eye in Rats

In rats, some parvocellular paraventricular neurons project to spinal autonomic centers. Using the virus tracing technique, we have demonstrated that some magnocellular paraventricular neurons, but not supraoptic neurons, also project to autonomic preganglionic centers of the mammary gland, gingiva, or lip. A part of these neurons has shown oxytocin immunoreactivity. In the present experiment, we have examined whether the same magnocellular neuron that sends fibers to the retina or autonomic preganglionic centers of the eye also projects to the posterior pituitary. Double neurotropic viral labeling and oxytocin immunohistochemistry were used. After inoculation of the posterior pituitary and the eye with viruses, spreading in a retrograde direction and expressing different fluorescence proteins, we looked for double-labeled neurons in paraventricular and supraoptic nuclei. Double-labeled neurons were observed in non-sympathectomized and cervical-sympathectomized animals. Some double-labeled neurons contained oxytocin. After the optic nerve was cut, the labeling did not appear in the supraoptic nucleus; however, it could still be observed in the paraventricular nucleus. In the paraventricular nucleus, the double-labeled cells may be the origin of centrifugal visual fibers or autonomic premotor neurons. In the supraoptic nucleus, all double-labeled neurons are cells of origin of centrifugal visual fibers

Location of glutamatergic/aspartatergic neurons projecting to the hypothalamic ventromedial nucleus studied by autoradiography of retrogradely transported [(3)H]d-ASPARTATE.

The hypothalamic ventromedial nucleus is a prominent cell group, which is involved in the control of feeding, sexual behavior and cardiovascular function as well as having other functions. The nucleus receives inputs from various forebrain structures and has a dense glutamatergic innervation. The aim of the present investigations was to reveal the location of glutamatergic neurons in the telencephalon and diencephalon projecting to this hypothalamic cell group. [(3)H]d-aspartate retrograde autoradiography was used injecting the tracer into the ventromedial nucleus. We detected radiolabeled neurons in telencephalic structures including the lateral septum, bed nucleus of the stria terminalis and the amygdala, and in various diencephalic regions, such as the medial preoptic area, hypothalamic paraventricular nucleus, periventricular nucleus, anterior hypothalamic area, ventral premamillary nucleus, thalamic paraventricular and parataenial nuclei and in the hypothalamic ventromedial nucleus itself. Our observations are the first data on the location of glutamatergic neurons terminating in the hypothalamic ventromedial nucleus. The findings indicate that glutamatergic innervation of the ventromedial nucleus is very complex