Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 21

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Electrophysiology of optic nerve input to the intergeniculate leaflet neurons in rats-in vitro studies

100%
Blasiak A., Lewandowski M. H.
Acta Neurobiologiae Experimentalis
|
2005
|
tom 65
|
nr 3
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Neurobiologiczne spojrzenie na pobudki naszych działań

100%
Blasiak A., Blasiak T.
Wszechświat
|
2022
|
tom 123
|
nr 01-03
3

In vitro neuronal activity of the rat intergeniculate leaflet

81%
Blasiak A., Blasiak T., Lewandowski M. H.
Acta Neurobiologiae Experimentalis
|
2001
|
tom 61
|
nr 3
4
Content available remote

Electrophysiology and pharmacology of the optic input to the rat intergeniculate leaflet in vitro

81%
Blasiak A., Blasiak T., Lewandowski M. H.
Journal of Physiology and Pharmacology
|
2009
|
tom 60
|
nr 1
171-180
The mammalian intergeniculate leaflet (IGL) of the thalamus is a neuronal element of the circadian timing system, which receives direct photic input from the retina. The purpose of this study was to analyze responses of rat IGL neurons in vitro to optic tract stimulation and to identify neurotransmitters released from the terminals of retinal ganglion cells in this structure. Following optic tract stimulation, most of the responding IGL cells were excited and only a minority of them were inhibited. Neurons showing the excitatory response were tested in the presence of AP-5, a selective antagonist of NMDA receptors. In most cases the responses were only partially inhibited by the presence of AP-5. Complete disappearance of excitatory responses was achieved by adding CNQX, an AMPA/kainate receptor-selective antagonist, to the standard incubation fluid. Inhibitory responses were blocked or considerably attenuated in the presence of bicuculline, a GABAA receptor antagonist, in the ACSF. This study demonstrated that glutamate is the main neurotransmitter mediating optic tract input to the IGL, acting mainly via non-NMDA ionotropic receptors. It was also shown that NMDA and GABAA receptors are involved in passing photic input to the IGL, albeit to a much lesser extent.
5
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Postawy i przekonania społeczeństwa wobec bobra europejskiego (Castor fiber L.) na terenie LKP Puszcza Notecka oraz LKP Puszcza Białowieska

81%
Loboda J., Blasiak A., Wierzbicka A.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 2[51]
6

Zainteresowanie rekreacją ruchową kobiet studiujących zaocznie

81%
Rodziewicz-Gruhn J., Blasiak A., Zarzeczna D.
Prace Naukowe Wyższej Szkoły Pedagogicznej w Częstochowie. Kultura Fizyczna
|
2000
|
tom 03
7

Dopaminergic signalling in nucleus incertus – unexpected inhibitory and excitatory effects of D2 activation

81%
Szlaga A., Gugula A., Sambak P., Blasiak A.
Acta Neurobiologiae Experimentalis
|
2018
|
tom 78
|
nr Suppl.1
Nucleus incertus (NI) is a brainstem structure involved in stress response, arousal, and food intake control. NI is a main source of relaxin-3 in the brain, and relaxin-3 was shown to alter reward and stress related behaviours. Re‑ cently, dopamine receptors were identified in the NI, how‑ ever the effect of their activation on NI neuronal activity was unknown. Therefore, the current study aimed to char‑ acterise the effect of dopamine receptor activation on NI neuronal activity, as well as identify the source of tyrosine hydroxylase (TH)-positive fibres in the structure. Wholecell patch-clamp recordings were used to assess the re‑ sponsiveness of NI neurons to selective D1R and D2R ag‑ onist application. Track-tracing combined with anti-TH immunohistochemical staining was used to define the source of TH immunoreactive fibres in the NI. D1R ago‑ nist SKF-81297 (10 µM) caused depolarization of NI cells by 5.01±0.75 mV (mean change ± SEM). Depolarization persist‑ ed in the presence of tetrodotoxin and glutamate/GABA receptors antagonists which indicates direct postsynaptic action of SKF-81297. Interestingly, activation of D2Rs with quinpirole (20 µM) induced both inhibitory and excitato‑ ry effects on NI neuron activity. In 56% of NI neurons an outward current (13.87±6.55 pA), decrease in action poten‑ tial firing frequency (3.47±1.33 Hz), and hyperpolarization of quiescent cells (2.16±1.01 mV) was observed after quin‑ pirole administration. In 28% of the neurons an increase in inward current amplitude (13.73±2.08 pA) and increase in frequency of action potentials (0.75±0.37 Hz) was recorded after quinpirole application. Both excitatory and inhibitory action of quinpirole persisted in the presence of tetrodo‑ toxin and GABA/glutamate receptors antagonists. Results of track-tracing experiments allowed identification of A11 and A13 cell groups as a source of dopamine innervation in the NI. D1R and D2R are localised postsynaptically on NI neurons. Surprisingly, D2R activation exerted both direct inhibitory and excitatory effects on NI neurons, suggesting a diverse action for dopamine receptor agonists on neuro‑ chemically and/or functionally distinct cell classes in this structure. Identification of A11 and A13 dopamine cells groups as a potential source of TH immunoreactive fibres in the NI allows us to conclude that dopaminergic inner‑ vation of the NI may be involved in the control of alertness and sensorimotor response to salient stimuli.
8

Zastosowanie naziemnego skanera laserowego do określenia miąższości drzew stojących w drzewostanie podokapowym

81%
Wegiel A., Ociepka S., Blasiak A.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
|
2018
|
tom 17
|
nr 3
9
Content available remote

The responsiveness of the rat intergeniculate leaflet neurons to glutamatergic agonists

81%
Blasiak A., Pekala D., Lewandowski M. H.
Journal of Physiology and Pharmacology
|
2007
|
tom 58
|
nr 4
The intergeniculate leaflet (IGL) has been shown to be a functional constituent of the circadian timing system. The IGL receives a monosynaptic input from the retina and is known to mediate some of the effects of light on the circadian clock. In the majority of retinal ganglion cells, glutamate functions as an excitatory neurotransmitter. The effect of monosodium glutamate and N-methyl-D-aspartate (NMDA), on the extracellularly recorded discharge activity of IGL neurons was studied in vitro. The application of monosodium glutamate induced either an excitatory, a biphasic or an inhibitory response. Application of NMDA induced an excitatory response in the majority of tested neurons. To determine the role of NMDA receptors in the response to glutamate application, the selective antagonist of NMDA receptors- AP-5, was applied to the incubation medium. The presence of AP-5 reduced the response of the IGL cells to focal application of glutamate and completely blocked their responsiveness to NMDA. To clarify whether GABAergic interneurons are involved in mediation of the inhibitory effects of glutamate, we repeated our experiments in the presence of bicuculline in the incubation medium. Since bicuculline did not influence the observed inhibitory effects, the involvement of GABAA receptors was excluded. The present study provides the first electrophysiological evidence that neurons in the rat IGL, respond to glutamate probably through NMDA receptors. However, our results also suggest that other types of glutamate receptors may play an additional role in mediating the action of this excitatory amino acid on the IGL neurons.
10

Maternal separation modifies dendritic spine density in ventral tegmental area neurons in a sub-region-specific manner: study in female rats

71%
Celary A., Gugula A., Tylko G., Hess G., Blasiak A.
Acta Neurobiologiae Experimentalis
|
2019
|
tom 79
|
nr Suppl.1
Early life stress disrupts development of the human and animal brain and increases the risk of psychophysiological disorders and susceptibility to addiction in adulthood. Maternal separation (MS), an animal model of early life stress, was shown to raise predisposition to addictive behaviours and change neuronal activity as well as dendritic spine density in a range of brain structures. Mesocorticolimbic dopaminergic pathways originating from the ventral tegmental area (VTA) play a crucial role in the development of addiction, however, the influence of MS on VTA neuronal architecture remains obscure. AIM(S): The current study aimed to verify the influence of MS on VTA neuronal dendritic spine density, a possible anatomical substrate of functional changes in the ascending dopaminergic pathways. METHOD(S): Female rat pups were separated from dams for 3 hours daily from PND2 to 14. At PND65, rats were decapitated, Golgi-Cox staining was performed, and the density of spines was calculated manually on I‑III‑ order dendrites. Given the functional and anatomical heterogeneity of the VTA, analyzed neurons were assigned to specified VTA sub‑regions. RESULTS: In rats subjected to MS, significantly lower density of dendritic spines on neurons in ventromedial (II‑order branches – 15%), dorsolateral (II‑ and III‑order segments – 24 – 23% respectively), and dorsomedial (I‑order branches – 25%) VTA, was observed when compared to control. No significant changes in spine density were observed in ventrolateral VTA (only 6% decrease in spine density). CONCLUSIONS: The observed decrease in dendritic spine density in VTA neurons can be linked to a reduced number of excitatory synapses that may underlie altered activity of mesocorticolimbic pathways, altered dopamine release, and increased susceptibility to addictions observed after MS and childhood trauma. Sub‑region specificity of observed changes points to varied sensitivity of VTA neurons to stress. FINANCIAL SUPPORT: Funding: NSC-Poland UMO‑2016/21/B/NZ4/00204.
11

Maternal separation stress alters excitability and stress induced c-fos expression in ventral tegmental area dopaminergic neurons of adult female rats

71%
Gugula A., Spyrka J., Cizio K., Hess G., Blasiak A.
Acta Neurobiologiae Experimentalis
|
2019
|
tom 79
|
nr Suppl.1
INTRODUCTION: Traumatic experiences in childhood and maternal separation (MS) in rodents disrupts proper development of the brain including dopaminergic (DA) mesocorticolimbic pathways originating from ventral tegmental area (VTA). Importantly, early‑life stress predisposes for neuropsychiatric disorders and addiction in adulthood. Moreover, MS stress increases the number of VTA tyrosine hydroxylase (TH) immunoreactive DA neurons, raises baseline dopamine levels, and increases its release in response to acute stress in adult rats. However, neuronal mechanisms of these changes have not been fully explored. AIM(S): The current study aimed at determining the influence of MS on VTA DA cells electrophysiology and responsiveness to acute stress at the level of c-fos expression. METHOD(S): Female rats were submitted to MS during PND 2‑14, 3 h daily. In adulthood, some of the rats were subjected to restraint stress and subsequently perfused. The VTA region was cut, stained against TH and c-fos, and double stained neurons were counted. Remaining animals were sacrificed and brain slices containing VTA were prepared for electrophysiological patch‑clamp experiments. Recorded biocytin‑filled cells were stained and assessed as TH+ or TH‑. RESULTS: Our data show that exposure to early life stress leads to a significant reduction of the rheobase and an increased number of action potentials generated vs. injected current – indices of neuronal excitability. Importantly, it was altered in both TH+ and TH‑ VTA neurons. MS combined with restraint stress significantly increased the number of dorsal but not ventral VTA TH+/c‑fos+ cells. CONCLUSIONS: Observed changes in excitability of VTA DA neurons may constitute a neuronal mechanism of the reported elevated dopamine release after MS. Our data indicate that MS alters reactivity of dorsal but not ventral VTA cells to acute stress, which suggests a greater raise in stress-induced DA release in structures innervated by the dorsal VTA. FINANCIAL SUPPORT: Funding: NSC-Poland UMO- ‑2016/21/B/NZ4/00204.
12

Relaxin-3/RXFP3 signalling in rat paraventricular nucleus: novel element in neural control of feeding

71%
Kania A., Grabowiecka A., Gundlach A. L., Lewandowski M. H., Blasiak A.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr Suppl.1
Relaxin-3 (RLX3) is recently discovered peptide of the insulin superfamily. The highly-conserved relaxin family peptide receptor 3(RXFP3) signalling system is associated with stress response and feeding behaviour. Central RLX3 injections stimulate feeding via RXFP3 in the paraventricular nucleus (PVN). We hypothesize that RLX3 exerts its orexigenic effect through inhibition of PVN oxytocin neurons activity. To investigate the influence of selective RXFP3 agonist RXFP#-A2, on the activity of magnocellular PVN neurons whole cell patch clamp recordings were performed on the rat brain slices. We have shown that selective RXFP3 agonist, reversibly inhibits electrical activity of magnocellular PVN neurons. Characterization of the recorded neurons was based on their electrophysiological properties and identification of their neurochemical content. Responsiveness of RLX3 neurons to stress factors and their impact on feeding behaviour allow us to hypothesize that this peptide is a bridge between chronic stress and overeating. Future patch clamp experiments with RLX3 antagonist, tract-tracing and behavioural studies will allow to further characterize the role of RLX3 in stress inducted overeating.
13

Relaxin-3 innervation of the intergeniculate leaflet in the rat

71%
Blasiak A., Blasiak T., Czubak W., Gundlach A., Lewandowski M.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
The intergeniculate leafl et of the thalamus (IGL), a subdivision of the lateral geniculate body, is a component of the biological clock, responsible for, amongst other things, the synchronizing effect of timed caloric restriction on locomotor activity in rodents. The IGL has a distinct functional and anatomical profi le amongst thalamic nuclei, including strong peptidergic inputs (e.g. orexin and PACAP). Recently a dense network of terminals immunoreactive for relaxin-3 (RLX3) was identifi ed in IGL. RLX3 is a newly discovered neuropeptide expressed in high levels in brain. The physiological actions of RLX3 are largely unknown, but recent studies have suggested infl uences on feeding, stress responses and spatial memory. The majority of RLX3 neurons are located in the nucleus incertus (NI), but prior anatomical studies have excluded the NI as a source of the RLX3 in the IGL. In this study, we used neural tract-tracing and immunohistochemistry to demonstrate that the major source of RLX3 fi bers within IGL originates from RLX3 neuron populations in the periventricular- and periaqueductal gray. Furthermore, some of these IGL-projecting RLX3 neurons express corticotropin-releasing factor receptors, indicating that the RLX3 innervation may transmit stress-related responses to the IGL. Since stress is one of the non-photic factors capable of synchronizing behavioural rhythmicity, our data suggest that RLX3 might be another key element in the complex mammalian circadian system.
14
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Stan wiedzy o zrównoważonym rozwoju w Wielkopolsce – czy edukacja jest potrzebna?

61%
Opalinska P., Krokowska-Paluszak M., Lukowski A., Blasiak A., Wierzbicka A., Skorupski M.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2018
|
tom 20
|
nr 1[55]
15

Repeated corticosterone treatment increases thin spine density in pyramidal neurons of deep layers of the rat primary motor cortex

61%
Guguła A., Blasiak A., Kula J., Kania A., Tylko G., Hess G.
Acta Neurobiologiae Experimentalis
|
2017
|
tom 77
|
nr Suppl.1
INTRODUCTION: Stress-related elevated glucocorticoid level disrupts performance of motor tests in rats but underlying neuronal mechanisms remain unknown. Repeated corticosterone injections serve as an animal model of prolonged stress. Recently we have shown that treatment with corticosterone influences both the electrophysiology and morphology of pyramidal neurons of rat primary motor cortex (M1). It enhances spontaneous glutamate release and has no effect on dendritic spine density in superficial layers of M1, whereas in deep layers it increases spine density but does not affect electrophysiology AIM(S): The current study aimed at identification of spine types in different layers of M1 and consequent judgment on their ability to form functional synapses. Investigating the density of various spine types would clarify the apparent discrepancy between our previous electrophysiological and morphological data. METHOD(S): Rats were injected with corticosterone for 7 days, twice-daily (control group received the vehicle) and then decapitated. Brains were removed and stained using the Golgi-Cox method. Images of layer II/III and V M1 pyramidal neurons were obtained and deconvolved. Mushroom, stubby and thin spines and filopodia were counted manually on representative dendrites from the apical and basal part of the neurons. RESULTS: In layer II/III of M1 the density of each morphological spine type remained unaltered by corticosterone treatment, however, it significantly elevated the density of thin spines in layer V neurons. Other spine types were not affected. CONCLUSIONS: These data suggest that previously observed increase in M1 layer V spine density was caused exclusively by thin spine number upsurge. Thin spines are considered immature and do not form functional synaptic connections, what further validates our previous electrophysiological data. Lack of morphological changes in layer II/III is congruent with the proposed corticosterone-induced pre-synaptic mechanism of enhanced glutamate release.
16
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Konsumpcja dziczyzny i jej wpływ na postrzeganie myślistwa -- badania pilotażowe w klubach seniora

61%
Opalinska P., Lukowski A., Krokowska-Paluszak M., Blasiak A., Wierzbicka A., Skorupski M., Jaszczak A.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 1[50]
17
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Akarofobia - czy rodzice z Wielkopolski boją się kleszczy?

61%
Blasiak A., Opalinska P., Lukowski A., Krokowska-Paluszak M., Wierzbicka A., Skorupski A.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 1[50]
18

Relaxin-3 in the hypothalamic paraventricular nucleus (PVN) of rat:electrophysiological approach to understand the sex-dependent relations between stress and feeding

61%
Kania A., Lewandowski M. H., Hess G., Hossain M. A., Gundlach A. L., Blasiak A.
Acta Neurobiologiae Experimentalis
|
2015
|
tom 75
|
nr Supl.
BACKGROUND AND AIMS: Relaxin-3 (RLN3) is recently discovered orexigenic peptide expressed in the brainstem. Neurons synthesizing RLN3 are highly responsive to stress factors, which makes RLN3 and its receptor (RXFP3) excellent candidates at the interface of stress- and feeding-related signaling. Hypothalamic paraventricular nucleus (PVN) is considered a main site of action for RXFP3-mediated food intake and weight gain; which appeared linked to inhibition of PVN oxytocin neurons. RLN3 role in appetite control is considered sexually differentiated since increased expression of RLN3 in the NI (associated with reduced c-fos expression in the PVN) was observed only in female binge eating rats. To characterize the RLN3 influence on PVN neurons we conducted in vitro patch clamp recordings. METHODS: Male Wistar rats and Sprague-Dawley rats of both sexes (4–6-week old) were used. Rats were anesthetized and the brains collected for whole cell patch clamp experiment on hypothalamic slices. All drugs were applied via bath perfusion. Immunofluorescent staining was carried out to further characterize recorded neurons. RESULTS: RXFP3-A2 (600 nM) – a selective RXFP3 agonist, inhibited the majority of recorded PVN neurons [the effect persisted in the presence of 0.5 μM TTX, glutamate and GABA receptor blockers (10 μM)]. Moreover, studies on Sprague Dawley PVN neurons indicate discrepancy in proportion of cells responsive to RXFP3 selective agonist with more neurons affected in female than male rats. Importantly, among PVN neurons sensitive to RXFP3 agonist oxytocin-positive cells were present. CONCLUSIONS: Our data support the hypothesis that the relaxin-3/RXFP3 network is associated with feeding control in both male and female rats, indicating higher sensitivity of female rats PVN neurons to RXFP3 activation. Currently we are exploring sexual differences in behavioral effects of hypothalamic RXFP3 activation under different stress and dietary conditions. Funding: NSC, Poland DEC-2012/05D/NZ4/02984 and MSHE, Poland 0020/ DIA/2014/43.
19
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

"Oko lasu" – obraz i współczesne media w ręku edukatora

61%
Krokowska-Paluszak M., Opalinska P., Lukowski A., Blasiak A., Wierzbicka A., Gruchala A., Skorupski M.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2018
|
tom 20
|
nr 1[55]
20
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Las i rola współczesnego leśnika widziane oczami społeczeństwa

51%
Krokowska-Paluszak M., Opalinska P., Lukowski A., Blasiak A., Wierzbicka A., Skorupski M., Sagan J., Gruchala A., Tomusiak R.
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
|
2017
|
tom 19
|
nr 1[50]
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.