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9 záznamů v Medvik Filtry

Článek

Combined administration of alpha1-adrenoceptor antagonist prazosin and beta-blocker propranolol impairs spatial avoidance learning on a dry arena

Behavioural brain research. 2010 ; 208 (2) : 402-407.

Behav Brain Res
ISSN 1872-7549
Medvik
Zdroj

Spatial learning is a widely studied type of animal behavior often considered as a model of higher human cognitive functions. Noradrenergic receptors play a modulatory role in many nerve functions, including vigilance, attention, reward, learning and memory. The present study aimed at studying the effects of separate or combined systemic administration of the alpha1-adrenergic antagonist prazosin (1 and 2 mg/kg) and beta-blocker propranolol (5 and 20 mg/kg) on the hippocampus-dependent learning in the active allothetic place avoidance (AAPA) task. Both centrally active drugs impaired spatial learning when administered together, exerting no effect in separate applications. Locomotion was impaired only in a combined application of higher doses of both drugs (2 mg/kg prazosin and 20 mg/kg propranolol). These results suggest an in vivo interaction between these two types of receptors in spatial navigation regulation.

Článek online

Vliv antagonistů noradrenergních receptorů na rozeznávání pozice pohybujícícho se objektu
[Effect of antagonists of noradrenergic receptors on recognition of position of a moving object]

Psychiatrie (Praha, Print). 2009 ; 13 (4) : 176-180.

ISSN 1211-7579
Medvik
Zdroj

Prostorová kognice je často používaný model pro výzkum paměti a učení. Behaviorální testy využívající počítačovou aparaturu umožňují snadnou modifikaci experimentu a širokou škálu prezentovaných stimulů. Vyvinuli jsme nový behaviorální test, v němž potkani pozorují pohybující se objekt a vyhodnocují jeho polohu. Během experimentu byli vyhladovělí potkani umístěni v modifikovaném Skinnerově boxu, který byl propojen s počítačem a monitorem. Pokud potkani provedli operantní odpověď (zmáčknutí páčky) ve chvíli, kdy se pohybující se objekt nacházel na monitoru v určené odměňované oblasti, bylo do krmítka v boxu doručeno několik potravinových pelet. Poté, co se potkani naučili tuto úlohu řešit, zkoumali jsme vliv antagonistů noradrenergních receptoru (αl-blokátoru prazosinu a δ-blokátoru propranololu) na řešení této úlohy. Podání prazosinu (2 a 3 mg/kg) vyvolalo snížení motorické aktivity, avšak neovlivnilo úspěšnost v operantní prostorové úloze. Propranolol v dávkách 18 a 20 mg/kg neovlivnil motorickou aktivitu a mírně narušil schopnost rozeznávat pohybující se objekt. Dávka propranololu 25 mg/kg narušila operantní chování (mačkání páčky).

Spatial cognition is often used as a model to study memory and learning. Behavioral tests using computer apparatus allow us to modify easily experiments and to present wide range of visual stimuli. We have developed a novel behavioral task, in which rats observe moving object and discriminate it`s position. During the experiment the food-deprivated rats were placed in a modified Skinner`s box connected with a computer and with a computer screen. In the case the rats made an operant response (lever press) when the moving object situated on the computer screen was in the rewarded area, a few food pellets were delivered to the feeder in the box as a reward. After the rats were able to solve this task, we have studied the effect of antagonists of adrenoceptors (?1-blocker prazosin and ß-blocker propranolol). Administration of prazosin (2 and 3 mg/kg) resulted in general depression of motoric activity with no selective influence upon spatial discrimination efficiency. Propranolol at doses 18 and 20 mg/kg didn’t affect motoric activity and slightly disrupted the ability of recognition of position of a moving object. A dose 25 mg/kg of propranolol disrupted operant behavior (lever pressing activity).

Článek online

Guidelines EAU pro benigní hyperplazii prostaty. 2. část

Urologické listy. 2009 ; 7 (4) : 61-80.

ISSN 1214-2085
Medvik
Zdroj

Článek online

Dopamine D2 receptors and alpha1-adrenoceptors synergistically modulate locomotion and behavior of rats in a place avoidance task

Behavioural brain research. 2008 ; 189 (1) : 139-144.

Behav Brain Res
ISSN 0166-4328
Medvik
Zdroj

The processing of spatial information is the focus of interest for many cognitive neuroscientists. Approximately 10 years ago, a novel behavioral paradigm called active allothetic place avoidance (AAPA) was designed allowing the simultaneous assessment of locomotor and spatial behavior. The present study describes the effect of the combined treatment of Long-Evans rats with alpha1-adrenergic and D2 antagonists prazosin (1mg/kg and 2 mg/kg) and sulpiride (10 mg/kg and 30 mg/kg) on locomotion and avoidance behavior in the AAPA task. Results show that co-application of both drugs leads to disturbances in locomotion and avoidance in rats at the doses, which caused no impairments when administered independently. This finding suggests that both types of receptors act synergistically to regulate locomotion and possibly spatial behavior.