Effects of atenolol injected into the nucleus accumbens septi in rats in the elevated plus-maze test

Author(s):  
Luis H. Llano López ◽  
Pablo Melonari ◽  
Marisa Olguin ◽  
Miriam Débora Fraile ◽  
Adriana I. Landa ◽  
...  

AbstractBackgroundIn previous studies, we have observed that glutamate antagonists injected within the nucleus accumbens septi (NAS) induced an anxiolytic-like effect in the elevated plus maze (EPM) test in rats. In the present study, the effect of Atenolol, a specific Beta Adreno-receptor antagonist in the EPM was studied in male rats bilaterally cannulated NAS.MethodsRats were divided into five groups that received either 1 μL injections of saline or atenolol in different doses (0.75, 1 or 2 μg/1 μL, n=15–16) 15 min before testing.ResultsTime Spent in the Open Arm was modified by treatment (F=4.563, p=0.006, df 3). This was increased by the lowest dose of atenolol (p<0.05), by the medium doses (p<0.001) and also by the highest dose (p<0.01). Time per Entry was modified by treatment (F=4.54, p=0.06, df 3). This parameter was increased by the lowest dose of atenolol (p<0.01), but not for the medium and higher doses.ConclusionsWe conclude that Atenolol beta receptor blockade in the accumbens lead to an anxiolytic-like effect related to an increase in the time spent in the open arm and in the time per entry, showing specific behavioral patterns.

2018 ◽  
Vol 29 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Augusto P.I. Gargiulo ◽  
María P. Gargiulo De Aranda ◽  
Mercedes M.L. Gargiulo ◽  
Angel J.M. Gargiulo ◽  
Andres Acuña ◽  
...  

AbstractBackground:In previous studies, we have observed that specificN-methyl-d-aspartic acid (NMDA) antagonists and non-NMDA antagonists injected within the nucleus accumbens septi (NAS) induced an anxiolytic-like effect in the plus maze test in rats. In the present study, the effect of intracanalicular blockade of NMDA receptors using dizocilpine in the plus maze was studied in male rats bilaterally cannulated NAS.Methods:Rats were divided into five groups that received either 1 μL injections of saline or dizocilpine (MK-801, [5R,10S]-[+]-5-methyl-10,11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine) in different doses (0.5, 1, 2, or 4 μg) 15 min before testing.Results:Time spent in the open arm increased under dizocilpine treatment with the two higher doses (2 and 4 μg, p<0.05), extreme arrivals were increased by the three higher doses (1 μg, p<0.05; 2 and 4 μg, p<0.01), and open arm entries by the three higher doses (1, 2, and 4 μg, p<0.05). A dose-effect relationship was observed in all cases.Conclusions:We conclude that dizocilpine-glutamatergic blockade in the accumbens lead to an anxiolytic-like effect and a behavioral disinhibition related to an increase in some motoric parameters, showing specific behavioral patterns.


2020 ◽  
Vol 79 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Augusto P.I. Gargiulo ◽  
Andrés Acuña ◽  
Mercedes M.L. Gargiulo ◽  
Ángel J.M. Gargiulo ◽  
Marcos C.J. Gargiulo ◽  
...  

2006 ◽  
Vol 1074 (1) ◽  
pp. 643-649 ◽  
Author(s):  
R. FARIA ◽  
A. MAGALHAES ◽  
P. R.R MONTEIRO ◽  
J. GOMES-DA-SILVA ◽  
M. AMELIA TAVARES ◽  
...  

2020 ◽  
Vol 14 (1) ◽  
pp. 36-51 ◽  
Author(s):  
George L. da Silva Oliveira ◽  
José C. Correia L. da Silva ◽  
Ana P. dos Santos C. L da Silva ◽  
Chistiane M. Feitosa ◽  
Fernanda R. de Castro Almeida

Background: Central nervous system disorders such as anxiety, depression and epilepsy are characterized by sharing several molecular mechanisms in common and the involvement of the L-arginine/NO pathway in neurobehavioral studies with β-caryophyllene is still little discussed. Objectives: One of the objectives of the present study was to demonstrate the anxiolytic behavioral effect of β-caryophyllene (β-CBP) in female Swiss mice, as well as to investigate the molecular mechanisms underlying the results obtained. Methods: This study evaluated the neurobehavioral effects of β-CBP using the open field test, rota-rod test, elevated plus maze test, novelty suppressed feeding test, tail suspension test and forced swim test, as well as pilocarpine, pentylenetetrazole and isoniazid-induced epileptic seizure models. Results:: The results demonstrated that the neuropharmacological activities of β-CBP may involve benzodiazepine/GABAergic receptors, since the pre-treatment of β-CBP (200 mg/kg) associated with flumazenil (5 mg/kg, benzodiazepine receptor antagonist) and bicuculline (1 mg/kg, selective GABAA receptor antagonist) reestablished the anxiety parameters in the elevated plus-maze test, as well as the results of reduced latency to consume food in the novelty suppressed feeding test. In addition to benzodiazepine/GABAergic receptors, the neuropharmacological properties of β-CBP may be related to inhibition of nitric oxide synthesis, since pre-treatment with L-arginine (500- 750 mg/kg) reversed significantly the anxiolytic, antidepressant and anticonvulsant activities of β-CBP. Conclusion: The results obtained provide additional support in understanding the neuromolecular mechanisms underlying the anxiolytic, antidepressant and anticonvulsive properties of β-CBP in female Swiss mice.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2341
Author(s):  
Conner W. Wallace ◽  
Nari S. Beatty ◽  
Sarah A. Hutcherson ◽  
Heather A. Emmons ◽  
Madison C. Loudermilt ◽  
...  

Diet-induced obesity reduces dopaminergic neurotransmission in the nucleus accumbens (NAc), and stressful weight loss interventions could promote cravings for palatable foods high in fat and sugar that stimulate dopamine. Activation of κ-opioid receptors (KORs) reduces synaptic dopamine, but contribution of KORs to lower dopamine tone after dietary changes is unknown. Therefore, the purpose of this study was to determine the function of KORs in C57BL/6 mice that consumed a 60% high-fat diet (HFD) for six weeks followed by replacement of HFD with a control 10% fat diet for one day or one week. HFD replacement induced voluntary caloric restriction and weight loss. However, fast-scan cyclic voltammetry revealed no differences in baseline dopamine parameters, whereas sex effects were revealed during KOR stimulation. NAc core dopamine release was reduced by KOR agonism after one day of HFD replacement in females but after one week of HFD replacement in males. Further, elevated plus-maze testing revealed no diet effects during HFD replacement on overt anxiety. These results suggest that KORs reduce NAc dopamine tone and increase food-related anxiety during dietary weight loss interventions that could subsequently promote palatable food cravings and inhibit weight loss.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Hirotaka Shoji ◽  
Tsuyoshi Miyakawa

AbstractThe elevated plus maze test is a widely used test for assessing anxiety-like behavior and screening novel therapeutic agents in rodents. Previous studies have shown that a variety of internal factors and procedural variables can influence elevated plus maze behavior. Although some studies have suggested a link between behavior and plasma corticosterone levels, the relationships between them remain unclear. In this study, we investigated the effects of experience with a battery of behavioral tests, the wall color of the closed arms, and illumination level on the behavior and plasma corticosterone responses in the elevated plus maze in male C57BL/6J mice. Mice were either subjected to a series of behavioral tests, including assessments of general health and neurological function, a light/dark transition test, and an open field test, or left undisturbed until the start of the elevated plus maze test. The mice with and without test battery experience were allowed to freely explore the elevated plus maze. The other two independent groups of naïve mice were tested in mazes with closed arms with different wall colors (clear, transparent blue, white, and black) or different illumination levels (5, 100, and 800 lx). Immediately after the test, blood was collected to measure plasma corticosterone concentrations. Mice with test battery experience showed a lower percentage of open arm time and entries and, somewhat paradoxically, had lower plasma corticosterone levels than the mice with no test battery experience. Mice tested in the maze with closed arms with clear walls exhibited higher open arm exploration than mice tested in the maze with closed arms with black walls, while there were no significant differences in plasma corticosterone levels between the different wall color conditions. Illumination levels had no significant effects on any measure. Our results indicate that experience with other behavioral tests and different physical features of the maze affect elevated plus maze behaviors. Increased open arm time and entries are conventionally interpreted as decreased anxiety-like behavior, while other possible interpretations are considered: open arm exploration may reflect heightened anxiety and panic-like reaction to a novel situation under certain conditions. With the possibility of different interpretations, the present findings highlight the need to carefully consider the test conditions in designing experiments and drawing conclusions from the behavioral outcomes in the elevated plus maze test in C57BL/6J mice.


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