
Gergely ZacharSemmelweis University | SOTE · Department of Anatomy, Histology and Embryology
Gergely Zachar
PhD Biology
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Publications (57)
Gestational exposure to valproic acid (VPA) is a valid rodent model of human autism spectrum disorder (ASD). VPA treatment is known to bring about specific behavioral deficits of sociability, matching similar alterations in human autism. Previous quantitative morphometric studies from our laboratory showed a marked reduction and defasciculation of...
Gestational exposure of mice to valproic acid (VPA) is one currently used experimental model for the investigation of typical failure symptoms associated with autism spectrum disorder (ASD). In the present study we hypothesized that the reduction of dopaminergic source neurons of the VTA, followed by perturbed growth of the mesotelencephalic dopami...
Aims:
The endocannabinoid system with its type 1 cannabinoid receptor (CB1 R) expressed in postmitotic neuroblasts is a critical chemotropic guidance module with its actions cascading across neurogenic commitment, neuronal polarization and synaptogenesis in vertebrates. Here, we present the systematic analysis of regional CB1 R expression in the d...
The current review is an update on experimental approaches in which birds serve as model species for the investigation of typical failure symptoms associated with autism spectrum disorder (ASD). The discussion is focused on deficiencies of social behavior, from social interactions of domestic chicks, based on visual and auditory cues, to vocal comm...
(1) Background: The objective of this study was to uncover genomic causes of parental care. Since birds do not lactate and, therefore, do not show the gene expressional changes required for lactation, we investigate gene expression associated with parenting in caring and non-caring females in an avian species, the small passerine bird zebra finch (...
Males and females often exhibit differences in behaviour, life histories and ecology, many of which typically are reflecting in their brains. Neuronal protection and maintenance include complex processes led by the microglia, which also interacts with metabolites such as hormones or immune components. Despite increasing interest in sex-specific bra...
d-Aspartate (d-Asp) and d-serine (d-Ser) have been proposed to promote early-phase LTP in vitro and to enhance spatial memory in vivo. Here, we investigated the behavioural effects of chronic consumption of d-Asp and d-Ser on spatial learning of mice together with the expression of NMDA receptors. We also studied the alterations of neurogenesis by...
Gestational exposure to valproic acid (VPA) is known to cause behavioral deficits of sociability, matching similar alterations in human autism spectrum disorder (ASD). Available data are scarce on the neuromorphological changes in VPA-exposed animals. Here, we focused on alterations of the dopaminergic system, which is implicated in motivation and...
The expression of the recently identified neuropeptide, amylin, is restricted in rodents to the postpartum preoptic area and may play a role in the control of parental behaviours and food intake. These processes are substantially different between bird and rodent parents as birds do not lactate but often show biparental care of the offspring. To es...
Recent studies of the brain mechanisms of parental behaviors have mainly focused on rodents. Using other vertebrate taxa, such as birds, can contribute to a more comprehensive, evolutionary view. In the present study, we investigated a passerine songbird, the zebra finch (Taeniopygia guttata), with a biparental caring system. Parenting-related neur...
Embryonic exposure to valproic acid (VPA) is known to produce sociability deficits, resembling human autistic phenotypes, in several vertebrate species. Animals living in groups prefer the proximity of peers and have the ability to perceive and to respond to social signals for modifying behavior. Chicks of Galliform birds, known to display early pr...
Social monogamy, typically characterized by the formation of a pair bond, increased territorial defense, and often biparental care, has independently evolved multiple times in animals. Despite the independent evolutionary origins of monogamous mating systems, several homologous brain regions and neuropeptides and their receptors have been shown to...
In a previous study, methylenedioxypyrovalerone (MDPV), a designer drug of the cathinone family, caused selective enhancement of Caspase3 immunoreactive (Casp3+) apoptotic cells in the nucleus accumbens (NAc) of 7‑day‑old mice. To further elaborate on the mechanism underlying MDPV‑elicited apoptosis, here, we investigated the appearance of Casp3+ c...
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Stress-induced cortical alertness is maintained by a heightened excitability of noradrenergic neurons innervating, notably, the prefrontal cortex. However, neither the signaling axis linking hypothalamic activation to delayed and lasting noradrenergic excitability nor the molecular cascade gating noradrenaline synthesis is defined. Here, we show th...
D-aspartate (D-Asp) modulates adult neural plasticity and embryonic brain development by promoting cell proliferation, survival and differentiation. Here, developmental changes of the excitatory amino acids (EAAs) L-Glu, L-Asp and D-Asp were determined during the first postembryonic days, a time window for early learning, in selected brain regions...
The member of synthetic cathinone family, methylenedioxypyrovalerone (MDPV), is a frequently used psychoactive drug of abuse. The objective of our study was to determine the effect of MDPV (administered from the 8th to the 14th day of gestation) on the behavior of neonatal and adolescent mice, as well as its effect on maternal care. We measured mat...
Melanin-concentrating hormone (MCH) is a potent orexigenic and sleep-promoting neuropeptide in mammals produced predominately by hypothalamic neurons which project to a wide variety of brain areas. Several MCH producing neurons contain MCH as the only neuropeptide, while others comprise cocaine- and amphetamine regulated transcript (CART) as well....
In vitro studies show that diclofenac inhibits enzymatic steroid glucuronidation. This study was designed to investigate the influence of diclofenac on the excretion of stanozolol and 3′-hydroxystanozolol via analyses in hair, blood and urine in vivo in a rat study. Brown Norway rats were administered with stanozolol (weeks 1–3) and diclofenac (wee...
In vitro studies show that diclofenac inhibits enzymatic steroid glucuronidation. This study was designed to investigate the influence of diclofenac on the excretion of stanozolol and 3'-hydroxystanozolol via analyses in hair, blood and urine in vivo in a rat study. Brown Norway rats were administered with stanozolol (weeks 1-3) and diclofenac (wee...
Behaviour of young domestic chicks when isolated from conspecifics is influenced by two conflicting drives: fear of potential predator and craving for company. The nucleus accumbens (Ac) has been suggested to influence social behaviour, as well as motivation in goal directed tasks. In the present study, the Ac of one-day-old domestic chicks was les...
Penduline tits are songbirds, used as model animals in numerous studies of sexual conflict. Nevertheless, the distribution of neuropeptides in the brain of this avian species remains largely unknown. Here we present some of the first results on distribution of vasotocin (AVT) and vasoactive intestinal peptide (VIP) in the brain of this songbird spe...
Blue tits (Cyanistes coeruleus) are songbirds, used as model animals in numerous studies covering a wide field of research. Nevertheless, the distribution of neuropeptides in the brain of this avian species remains largely unknown. Here we present some of the first results on distribution of Vasotocine (AVT) and Vasoactive intestinal peptide (VIP)...
Chiral capillary electrophoresis method has been developed for quantitative determination of D-amino acid modulators of NMDA glutamate receptor; D-serine and D-aspartate along with L-glutamate and L-aspartate in biological samples. These ligands are suggested to be involved in regulation of NMDA receptor related brain functions, such as neurogenesi...
drugs have become a distinct social problem and health hazard in Europe and the US, and their abuse has increased dramatically in the last decade. Selective effects of these agents on animal behavioral parameters may help in better understanding of the potential risks of human drug abuse. In the present study, the effects of three different abusive...
Vasopressin influences social behaviour in mammals, in particular social recognition and bonding. However, much less is known about its avian analogue, vasotocin, although vasotocin appears to modulate singing behaviour and agonistic interactions together with vasoactive intestinal peptide (VIP) in some songbirds. The objectives of our study were t...
Testosterone and epitestosterone are mainly excreted as glucuronides. The aim of this study was to develop and validate a method using liquid chromatography tandem mass spectrometry (LC-MS/MS) to analyse testosterone and epitestosterone in rat serum and urine to assist in vivo studies on steroid metabolism. The method was developed by spiking charc...
We assembled a de novo transcriptome of short-read Illumina RNA-Seq data generated from telencephalon and diencephalon tissue samples from the Kentish plover, Charadrius alexandrinus. This is a species of considerable interest in behavioural ecology for its highly variable mating system and parental behaviour, but it lacks genomic resources and is...
Background
Anabolic androgenic steroids, such as stanozolol, are typically misused by athletes during preparation for competition. Out-of-competition testing presents a unique challenge in the current anti-doping detection system owing to logistic reasons. Analysing hair for the presence of a prohibited drug offers a feasible solution for covering...
Figure S1. Calibration curves of stanozolol and 3′-hydroxystanozolol in (a) hair, (b) urine and (c) serum.
Several studies have shown that L-aspartate (Asp) is present in synaptic vesicles and released exocytotically from presynaptic terminals, possibly by Ca(2+)-dependent corelease of Asp and L-glutamate (Glu). It has been demonstrated that both excitatory amino acids (EAAs) are released from the rat striatum as part of corticostriatal neurotransmissio...
Chiral capillary electrophoresis method has been developed to separate aspartate and glutamate enantiomers to investigate the putative neuromodulator function of D-Asp in the central nervous system. To achieve appropriate detection sensitivity fluorescent derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and laser-induced fluorescence detec...
It has long been proposed that L: -aspartate (Asp) is an excitatory neurotransmitter similar to L: -glutamate (Glu) but with distinct signaling properties. The presence of Asp in excitatory synapses of the medial striatum/nucleus accumbens of domestic chicks suggests that Asp plays a role of neurotransmitter also in the avian brain. Neurotransmitte...
To understand better the rate of neurogenesis and the distribution of new neurons in posthatch domestic chicks, we describe and compare the expression of the neuronal nuclei protein (NeuN, a.k.a. Fox-3) and doublecortin antigens in the whole brain of chicks 2 days, 8 days, and 14 weeks posthatch. In the forebrain ventricular and paraventricular zon...
Three different fluorescent tags have been compared for the quantitative analysis of aspartate and glutamate in brain microdialysate samples. Separation conditions have been optimized to achieve short analysis time using reversed polarity separation in coated capillary. Method validation has revealed similar quantification limit of 0.1 μM of analyt...
Standard laboratory tests measure the degree of anxiety using the rats’ aversion to open spaces, an adaptive behaviour to avoid predators. In a similar situation, young domestic chicks actively search for the proximity of conspecifics and frequently emit distress calls (DC). In the presence of a predator the adaptive behavior involves reduction of...
Vasopressin, VT and VIP play important roles in sexual behaviour of vertebrates. Here we focus on mating and parental behaviour, and compare VT and VIP distributions in the brains of two songbird species with different reproductive strategies: monogamous and biparental blue tits (Cyanistes coeruleus), versus polygamous and uniparental Eurasian pend...
G Gáti M Morawski D Lendvai- [...]
A Alpár
Extracellular matrix components consisting of large aggregating chondroitin sulphate proteoglycans accumulate around neuronal perikarya to establish perineuronal nets. These perineuronal nets surround subpopulations of neurons in many vertebrates including man. In chickens, perineuronal nets show very fast matrix maturation after hatching which is...
We performed a quantitative analysis of the postnatal formation of new cells in two midbrain nuclei of young domestic chicks 24 hours following passive avoidance learning. Two groups of one-day-old chicks were presented with a bead coated in water (PALW) or the aversive substance metylanthranilate (MeA). MeA chicks learned to associate the bead wit...
Alcohol administration causes apoptosis in most areas of the brain in rodents, however alcohol might cause increased cell proliferation in some regions. Although the domestic chick is widespread as an embryonic model of different neurotoxic effects, the postnatal effects of alcohol are less studied.In our study the formation of new cells in young c...
Lesion of the septal nuclei causes impairment in spatial memory and reduces anxiety and corticosterone response to stressful stimuli in rats. Data suggest that in avian species the septum plays a role in social and spatial behaviours, as well as in the regulation of anxiety, however, no lesion studies have been carried out so far to confirm such fu...
The afferents to the septum of the domestic chicken were studied using retrograde tracers, rhodamine conjugated latex bead or Fast Blue, placed in different septal subregions. The results were verified by anterograde tracer injections deposited to selected areas. The main telencephalic afferents to the septum arise ipsilaterally from the hippocampa...
Subpallial structures are highly conserved across the different vertebrate species. They are instrumental in the neural processing relevant to adaptive learning, decision making, motivation and behavioural strategies. Of the striatal regions, our attention has been focussed on the medial and ventral striatum (MSt), now parcellated into subregions,...
Young naive domestic chicks readily attack green insects and avoid insects painted red but show no discrimination of the same colours when applied to fruit-like objects, a discrimination that has been depicted as context-dependent preference. To study the neural representation of such preference we performed bilateral telencephalectomy on 1-day-old...
The striatum is reciprocally connected to the brainstem dopaminergic nuclei and receives a strong dopaminergic input. In the present study the spatial relation between the dopaminergic and dopaminoceptive structures of the avian medial striatum (formerly: lobus parolfactorius) was observed by confocal laser scanning microscope in the domestic chick...
Effects of bilateral chemical lesions of the medial basal ganglia [lobus parolfactorius (LPO)] were examined in 7- to 14-d-old domestic chicks. Chicks were trained in a color discrimination task, in which the subject had to peck one of the two colored beads associated with rewards that differed in quantity (amount of food) and/or temporal proximity...
Effects of bilateral chemical lesions of the ventro-medial basal ganglia (lobus parolfactorius, LPO) were examined in 3-9-day-old domestic chicks. In experiment-1, chicks were trained to peck at a blue bead that was associated with drops of water as a reward. Addition of passive avoidance training using a bitter yellow bead resulted in highly selec...
A kutatóprogram a viselkedés motivációjának idegi alapjait vizsgálja multidiszciplináris megközelítéssel, madár idegrendszeri modell felhasználásával. A vizsgálatból extrapolálható eredmények felhasználhatók az emlős viszonyok leírására és értelmezésére is. A kutatócsoport korábbi nemzetközi tapasztalataira épülő program megvalósításával a következ...