Fluoxetine reverses the behavioral despair induced by neurogenic stress in mice: role of N-methyl-d-aspartate and opioid receptors

2016 ◽  
Vol 94 (6) ◽  
pp. 599-612 ◽  
Author(s):  
Arya Haj-Mirzaian ◽  
Nastaran Kordjazy ◽  
Sattar Ostadhadi ◽  
Shayan Amiri ◽  
Arvin Haj-Mirzaian ◽  
...  

Opioid and N-methyl-d-aspartate (NMDA) receptors mediate different effects of fluoxetine. We investigated whether opioid and NMDA receptors are involved in the protective effect of fluoxetine against the behavioral despair induced by acute physical stress in male mice. We used the forced swimming test (FST), tail suspension test (TST), and open-field test (OFT) for behavioral evaluation. We used fluoxetine, naltrexone (opioid receptor antagonist), MK-801 (NMDA receptor antagonist), morphine (opioid receptor agonist), and NMDA (NMDA receptor agonist). Acute foot-shock stress (FSS) significantly induced behavioral despair (depressive-like) and anxiety-like behaviors in tests. Fluoxetine (5 mg/kg) reversed the depressant-like effect of FSS, but it did not alter the locomotion and anxiety-like behavior in animals. Acute administration of subeffective doses of naltrexone (0.3 mg/kg) or MK-801 (0.01 mg/kg) potentiated the antidepressant-like effect of fluoxetine, while subeffective doses of morphine (1 mg/kg) and NMDA (75 mg/kg) abolished this effect of fluoxetine. Also, co-administration of subeffective doses of naltrexone (0.05 mg/kg) and MK-801 (0.003 mg/kg) with fluoxetine (1 mg/kg) induced a significant decrease in the immobility time in FST and TST. Our results showed that opioid and NMDA receptors (alone or in combination) are involved in the antidepressant-like effect of fluoxetine against physical stress.

Endocrinology ◽  
2012 ◽  
Vol 153 (5) ◽  
pp. 2323-2331 ◽  
Author(s):  
Cristiane Busnardo ◽  
Carlos C. Crestani ◽  
Leonardo B. M. Resstel ◽  
Rodrigo F. Tavares ◽  
José Antunes-Rodrigues ◽  
...  

We report changes in plasma arginine vasopressin (AVP) and oxytocin (OT) concentrations evoked by the microinjection of l-glutamate (l-glu) into the hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN) of unanesthetized rats, as well as which local mechanisms are involved in their mediation. l-Glu microinjection (10 nmol/100 nl) into the SON increased the circulating levels of both AVP and OT. The AVP increases were blocked by local pretreatment with the selective non-N-methyl-d-aspartate (NMDA) receptor antagonist 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX) (2 nmol/100 nl), but it was not affected by pretreatment with the NMDA-receptor antagonist LY235959 (2 nmol/100 nl). The OT response to l-glu microinjection into the SON was blocked by local pretreatment with either NBQX or LY235959. Furthermore, the administration of either the non-NMDA receptor agonist (±)-α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid hydrobromide (AMPA) (5 nmol/100 nl) or NMDA receptor agonist NMDA (5 nmol/100 nl) into the SON had no effect on OT baseline plasma levels, but when both agonists were microinjected together these levels were increased. l-Glu microinjection into the PVN did not change circulating levels of either AVP or OT. However, after local pretreatment with LY235959, the l-glu microinjection increased plasma levels of the hormones. The l-glu microinjection into the PVN after the local treatment with NBQX did not affect the circulating AVP and OT levels. Therefore, results suggest the AVP release from the SON is mediated by activation of non-NMDA glutamate receptors, whereas the OT release from this nucleus is mediated by an interaction of NMDA and non-NMDA receptors. The present study also suggests an inhibitory role for NMDA receptors in the PVN on the release of AVP and OT.


2006 ◽  
Vol 290 (3) ◽  
pp. R642-R651 ◽  
Author(s):  
Chun-Yi Hung ◽  
M. Covasa ◽  
R. C. Ritter ◽  
G. A. Burns

Hindbrain administration of MK-801, a noncompetitive N-methyl-d-aspartate (NMDA) channel blocker, increases meal size, suggesting NMDA receptors in this location participate in control of food intake. However, dizocilpine (MK-801) reportedly antagonizes some non-NMDA ion channels. Therefore, to further assess hindbrain NMDA receptor participation in food intake control, we measured deprivation-induced intakes of 15% sucrose solution or rat chow after intraperitoneal injection of either saline vehicle or d(-)-2-amino-5-phosphonopentanoic acid (AP5), a competitive NMDA receptor antagonist, to the fourth ventricular, or nucleus of the solitary tract (NTS). Intraperitoneal injection of AP5 (0.05, 0.1, 1.0, 3.0, and 5.0 mg/kg) did not alter 30-min sucrose intake at any dose (10.7 ± 0.4 ml, saline control) (11.0 ± 0.8, 11.2 ± 1.0, 11.2 ± 1.0, 13.1 ± 2.2, and 11.0 ± 1.9 ml, AP5 doses, respectively). Fourth ventricular administration of both 0.2 μg (16.7 ± 0.6 ml) and 0.4 μg (14.9 ± 0.5 ml) but not 0.1 and 0.6 μg of AP5 significantly increased 60-min sucrose intake compared with saline (11.2 ± 0.4 ml). Twenty-four hour chow intake also was increased compared with saline (AP5: 31.5 ± 0.1 g vs. saline: 27.1 ± 0.6 g). Furthermore, rats did not increase intake of 0.2% saccharin after fourth ventricular AP5 administration (AP5: 9.8 ± 0.7ml, vs. saline: 10.5 ± 0.5ml). Finally, NTS AP5 (20 ng/30 nl) significantly increased 30- (AP5: 17.2 ± 0.7 ml vs. saline: 14.6 ± 1.7 ml), and 60-min (AP5: 19.4 ± 0.6 ml vs. saline: 15.5 ± 1.4 ml) sucrose intake, as well as 24-h chow intake (AP5: 31.6 ± 0.3 g vs. saline: 26.1 ± 1.2 g). These results support the hypothesis that hindbrain NMDA receptors participate in control of food intake and suggest that this participation also may contribute to control of body weight over a 24-h period.


1994 ◽  
Vol 267 (4) ◽  
pp. R1065-R1070 ◽  
Author(s):  
H. Ohta ◽  
W. T. Talman

In this study, we determined whether either N-methyl-D-aspartate (NMDA) receptors or non-NMDA receptors in the nucleus tractus solitarii (NTS) participate in the baroreceptor reflex in rats. Microinjection of an NMDA receptor antagonist, MK-801, and a non-NMDA receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione, into the NTS decreased the sensitivity of the baroreceptor reflex by 51 and 41%, respectively. Simultaneous administration of both agents further reduced the sensitivity of the baroreceptor reflex to 28% of control. A competitive NMDA receptor antagonist, 2-amino-5-phosphonovaleric acid, also attenuated reflex bradycardia or tachycardia elicited by a single dose of phenylephrine or nitroprusside, respectively. Specificity of each antagonist's effects was supported by selective blockade of depressor responses produced by agonists that act at the NMDA and non-NMDA receptors, respectively. Results of this study indicate that both non-NMDA- and NMDA-sensitive receptors are involved in baroreceptor reflex transmission in the NTS.


2009 ◽  
Vol 79 (5) ◽  
pp. 951-957 ◽  
Author(s):  
Zhi Yang ◽  
Yan Wang ◽  
Wei Luo ◽  
Xiaochuan Hua ◽  
Peter Wamalwa ◽  
...  

Abstract Objective: To test the hypothesis that peripheral N-methyl-D-aspartate (NMDA) receptors play a role in pain induced by experimental tooth movement. Materials and Methods: Male Sprague-Dawley rats weighing between 200 g and 300 g were used in this study. Expression of NMDA receptors subunit 1 (NMDAR1) in the mandibular portion of the trigeminal ganglion (TG) was determined by Western blotting 4 hours and 1, 2, 3, 5, 7, and 14 days after tooth movement. Changes in the time taken by the rats on nocifensive behavior then effects of NMDA receptor antagonist MK-801 and force magnitude on these changes in behavior and NMDAR1 expression were evaluated. Results: Experimental tooth movement led to a statistically significant increase in NMDAR1 expression at protein level from day 1 to 7 after force application initiating tooth movement. Time spent on nocifensive behavior dramatically increased from day 1 to 7. The rhythm in NMDAR1 expression in the TG and behavioral activities correlated well with the initial orthodontic pain responses. The magnitude of the nocifensive behavior and NMDAR1 expression were both force magnitude dependent and could be reduced by peripheral NMDA receptor antagonist MK-801. Conclusions: The hypothesis is accepted. Peripheral NMDA receptors are modulated by experimental tooth movement and involved in the development of tooth movement pain.


Sign in / Sign up

Export Citation Format

Share Document