Effects of ifenprodil on the antidepressant-like activity of NMDA ligands in the forced swim test in mice

Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

Contents lists available at ScienceDirect

Progress in Neuro-Psychopharmacology & Biological Psychiatry journal homepage: www.elsevier.com/locate/pnp

Effects of ifenprodil on the antidepressant-like activity of NMDA ligands in the forced swim test in mice Ewa Poleszak a,⁎, Sylwia Wośko a, Anna Serefko a, Aleksandra Szopa a, Aleksandra Wlaź b, Bernadeta Szewczyk c, Gabriel Nowak c,d, Piotr Wlaź e a

Department of Applied Pharmacy, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, PL 20-090 Lublin, Poland Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, PL 31-343 Kraków, Poland d Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, PL 30-688 Kraków, Poland e Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland b c

a r t i c l e

i n f o

Article history: Received 23 February 2013 Received in revised form 30 April 2013 Accepted 4 June 2013 Available online 14 June 2013 Keywords: Antidepressant-like activity Forced swim test Ifenprodil Mice NMDA receptor ligands

a b s t r a c t Multiple pre-clinical and clinical studies clearly displayed implication of the NMDA receptors in development of depressive disorders since a variety of NMDA receptor antagonists exhibit an antidepressant-like effect. The main aim of our study was to assess the influence of ifenprodil — an allosteric modulator selectively binding at the NR2B subunit on the performance in the forced swim test in mice of various NMDA receptor ligands interacting with distinct components of the NMDA receptor complex. Ifenprodil at a dose of 10 mg/kg enhanced the antidepressant-like effect of CGP 37849 (a competitive NMDA receptor antagonist, 0.312 mg/kg), L-701,324 (an antagonist at glycine site, 1 mg/kg), MK-801 (a non-competitive antagonist, 0.05 mg/kg) and D-cycloserine (a partial agonist of a glycine site, 2.5 mg/kg) but it did not shorten the immobility time of animals which concurrently received an inorganic modulator of the NMDA receptor complex, such as Zn2+ (2.5 mg/kg) or Mg2+ (10 mg/kg). On the other hand, the antidepressant-like effect of ifenprodil (20 mg/kg) was reversed by N-methyl-D-aspartic acid (an agonist at the glutamate site, 75 mg/kg) or D-serine (an agonist at the glycine site, 100 nmol/mouse). In conclusion, the antidepressant-like potential of ifenprodil given concomitantly with NMDA ligands was either reinforced (in the case of both partial agonist and antagonists, except for magnesium and zinc) or diminished (in the case of conventional full agonists). © 2013 Elsevier Inc. All rights reserved.

1. Introduction Depression is one of the most common recurring psychiatric diseases widespread all over the world, which prevalence is still increasing. Development of depressive disorders is preliminarily associated with disturbances in noradrenergic and serotonergic transmission in brain (Willner et al., 2012). However, multiple pre-clinical and clinical studies clearly displayed implication of the ionotropic NMDA receptors, as well. Alterations of the glutamate levels and NMDA receptor abnormalities were observed in depressive patients participating in clinical trials (Hashimoto, 2009; Law and Deakin, 2001; Nowak et al., 2003; Sanacora et al., 2004). Moreover, the involvement of the NMDA Abbreviations: CGP 37849, DL-/E/-amino-4-methyl-5-phosphono-3-pentenoic acid; DCS, D-cycloserine (D-4-amino-3-isoxazolidone); DS, D-serine; FST, forced swim test; i.c.v, intracerebroventricularly; i.p, intraperitoneally; L-701,324, 7-chloro-4-hydroxy3-(3-phenoxy)phenylquinolin-2[1H]-one; MK-801, dizocilpine ((5R,10S)-(+)-5-methyl10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate); NMDA, N-methyl-D-aspartate; TST, tail suspension test. ⁎ Corresponding author. Tel.: +48 81 742 38 08. E-mail address: [email protected] (E. Poleszak). 0278-5846/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pnpbp.2013.06.001

neurotransmission in the antidepressant-like effects of paroxetine and tianeptine has been reported (Ghasemi et al., 2009; Wlaź et al., 2011). Similar interactions between the NMDA receptor ligands and imipramine, fluoxetine and reboxetine were noticed by Poleszak et al. (2011). The NMDA receptor heteromeric complex is considered as a tetramer comprising two glycine-binding NR1 subunits with two glutamatebinding NR2 subunits or, less frequently two glycine-binding NR3 subunits. NR1 subunit, ubiquitously distributed in central nervous system, is encoded by a single gene but occurs as eight distinct isoforms. NR2 subunits (NR2A, NR2B, NR2C and NR2D) are encoded by four different genes. Their distribution in the central nervous system is not uniform — NR2A subunits are commonly found in the brain whereas NR2B expression is restricted primarily to the forebrain; NR2C subunits are predominantly localised in the cerebellum. The type of NR2 subunit is thought to determine functional and pharmacological properties of the whole NMDA receptor complex (Bhatt et al., 2013; Traynelis et al., 2010; Williams, 2009). There are numerous binding sites within the NMDA receptor complex, i.e. a binding site for glycine or D-serine, a glutamic acid binding site, the binding sites for zinc, magnesium, polyamines, redox agents and others (Monaghan and Jane, 2009).

30

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

A variety of NMDA receptor antagonists exhibited an antidepressantlike effect, measured by the forced swim test (FST) and/or tail suspension test (TST) in animal models (Maj et al., 1992b, 1992c; Poleszak et al., 2007a; Rosa et al., 2003). Their activity was comparable to that observed for antidepressant used in clinical practise (Decollogne et al., 1997; Lopes et al., 1997; Wędzony et al., 1995). Yet, high-affinity NMDA receptor blockers like MK-801 and phencyclidine, acting within the ion channel or CGP 37849, an inhibitor of the glutamate site, exert severe side effects (like ataxia, memory loss, increased locomotion) that disqualify them from clinical utility (Farlow, 2004; Tricklebank et al., 1989; Willetts et al., 1990). However, ketamine, traxoprodil and memantine were successfully used in depressive patients (Berman et al., 2000; Preskorn et al., 2008; Zarate et al., 2006a, 2006b). Ifenprodil and its analogues devoid of many adverse reactions, seem to be more promising, better tolerated agents. According to Kew et al. (1996), ifenprodil effectively inhibits the NMDA receptors activated by high concentrations of glutamate; though this inhibition is not thorough — the basal level of glutamate neurotransmission remains. In contrast, the first-generation NMDA receptor antagonists cause the generalised blockage of receptor activity. Such dissimilarity in drug action may be responsible for the differences in their safety profiles (Bhatt et al., 2013; Mony et al., 2011). As the conventional antidepressant therapy is not sufficient, due to the frequent lack of clinical efficacy along with the undesirable side effects, scientists still search for better alternatives (i.e. new compounds or safe combinations of the well-known agents) (Willner et al., 2012). The main objection of our study was to assess the influence of ifenprodil — an allosteric modulator selectively binding at the NR2B subunit, on the performance in the FST in mice of various NMDA receptor ligands interacting with distinct components of the NMDA receptor complex. The FST, besides TST, is the most popular validated model evaluating an antidepressant activity of substances (Petit-Demouliere et al., 2005).

— 10 mg/kg and 2.5 mg/kg, respectively. All substances (except for L-701,324) were dissolved in physiological saline. L-701,324 was suspended in a 1% aqueous solution of Tween 80 (POCH). All solutions were prepared immediately prior to the experiment. The solutions were administered intraperitoneally (i.p.), except for D-serine which was administered intracerebroventricularly (i.c.v.) according to a modified method described by Lipman and Spencer (1980). Ifenprodil, NMDA, CGP 37849, D-cycloserine, L-701,324, MK-801 and zinc hydroaspartate were given 60 min before behavioural testing while magnesium hydroaspartate and D-serine were injected 30 min and 15 min before the experiment, respectively. The active and ineffective doses of drugs were selected on the basis of the results of previous experiments (Poleszak et al., 2007a, 2011; Szewczyk et al., 2009). The active and sub-effective doses of ifenprodil have been selected on the basis of the unpublished outcomes of previous tests performed in our laboratory. Animals from the control groups received i.p. or i.c.v. injections of saline (vehicle), depending on the tested group. In order to avoid the risk of obtaining the false results caused by an additional activation of glutamatergic system after i.c.v. administration, each animal in the experiments with D-serine was given an i.c.v. injection — either D-serine or vehicle. The volume of vehicle or drug solutions for i.p. administration was 10 ml/kg and for i.c.v. administration was 5 μl per mouse. 2.3. Forced swim test

2. Methods

Forced swim test was performed according to the method described by Porsolt et al. (1977). Mice were individually placed into the glass cylinders (height 25 cm, diameter 10 cm) containing 10 cm of water at 23–25 °C. The animals were left in the cylinders for 6 min. The total duration of immobility was recorded during the last 4 min of the 6-min testing period. The mice were judged to be immobile when they ceased struggling and remained floating motionless in the water, making only the movements necessary to keep their heads above the water level.

2.1. Animals

2.4. Spontaneous locomotor activity

Experiments were conducted on naïve adult male Albino Swiss mice (25–30 g). The animals were housed in groups of 10 in standard cages, in the environmentally controlled rooms, under a 12:12 h light/dark cycle. They had free access to food and water except for the short time when they were removed from their home cages for testing. The experiments began after at least 1-week acclimation period in the laboratory conditions. Each experimental group consisted of 8–11 randomly assigned animals. Each mouse was tested only once. Separate groups of animals were used in the FST and in the locomotor studies. All experimental procedures involving animals were conducted in accordance with European Union and Polish legislation acts concerning animal experimentation. They were approved by the Local Ethics Committee at the Medical University of Lublin. All efforts were made to minimize animal suffering and to reduce the number of mice used in the experiments.

In order to ensure that the changes in motor activity of mice did not disturb the interpretation of the results obtained in the FST, the spontaneous locomotor activity was measured using an animal activity meter Opto-Varimex-4 Auto-Track (Columbus Instruments, Columbus, OH, USA). This automatic device consists of four transparent cages with a lid, set of four infrared emitters (each emitter has 16 laser beams) and four detectors monitoring animal movements. Mice were placed individually in the cages for 30 min. Activity was evaluated between the 2nd and the 6th minute, which corresponds with the time interval analysed in the FST. The spontaneous locomotor activity was measured by determining the amount of distance travelled in centimetres.

2.2. Drugs The following agents were used: ifenprodil (10 mg/kg or 20 mg/kg, Sigma), NMDA (N-methyl-D-aspartic acid, 75 mg/kg, Sigma), CGP 37849 (dl-(E)-amino-4-methyl-5-phosphono-3-pentenoic acid, 0.3 mg/kg, Abcam Biochemicals), D-cycloserine (d-4-amino-3-isoxazolidone, 2.5 mg/kg, Sigma), L-701,324 (7-chloro-4-hydroxy-3-(3-phenoxy) phenylquinolin-2[1H]-one, 1 mg/kg, Sigma), MK-801 (dizocilpine, (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5, 10-imine hydrogen maleate, 0.05 mg/kg, Sigma), D-serine (100 nmol/ mouse, Sigma), magnesium hydroaspartate (Farmapol, Poznań, Poland) and zinc hydroaspartate (Farmapol, Poznań, Poland). Dosages of magnesium and zinc referred to pure magnesium and zinc ions

2.5. Statistical analysis The obtained data were assessed by the one-way analysis of variance (ANOVA) followed by Student–Newman–Keuls post hoc test. All results were presented as the means ± standard error of the mean (SEM). p b 0.05 was considered as a statistically significant difference. 3. Results 3.1. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of CGP 37849 on the immobility time in the FST in mice Fig. 1 shows that the joint administration of ifenprodil and CGP 37849 produced a significant reduction in the immobility time of animals in the FST, though neither of the substances at the used doses exerted the effect by itself. However, this anti-immobility effect was only observed in comparison to the CGP 37849 group. One-way

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

31

Table 1 Influence of joint administration of ifenprodil and other NMDA receptor ligands on mice locomotion. Treatment (A) Saline IF (10 mg/kg) CGP 37849 (0.3 mg/kg) IF/CGP 37849

Fig. 1. Effect of joint administration of ifenprodil (IF) and CGP 37849 in the FST in mice. IF (10 mg/kg) and CGP 37849 (0.3 mg/kg) were administered i.p. 60 min before the test. The values represent the mean + SEM (n = 9–10 mice per group). *p b 0.05 versus CGP 37849 (Student–Newman–Keuls post hoc test).

ANOVA revealed the following statistics: F(3,33) = 2.93, p = 0.048. Neither ifenprodil nor CGP 37849 affected the locomotor activity on its own, however, the concomitant used of the substances reduced animals locomotion between 2nd and 6th minute of the experiment (Table 1).

3.2. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of D-cycloserine on the immobility time in the FST in mice The effects of treatment with ifenprodil and D-cycloserine on the immobility scores were presented in Fig. 2. Co-administration of the non-effective doses of the tested substances caused an antidepressantlike effect in the FST in mice, as compared to both the single-treated and vehicle-treated animals. One-way ANOVA pointed at a statistically significant differences between the tested groups (ANOVA: F(3,31) = 6.002, p = 0.0024). Based on the findings presented in Table 1, there was no considerable difference between the distances travelled by animals from all experimental groups.

3.3. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of L-701,324 on the immobility time in the FST in mice As depicted in Fig. 3, concomitant administration of per se inactive doses of ifeprodil and L-701,324 shortened the total duration of mice immobility, compared with the either drug alone as well as the vehicle-treated group. One-way ANOVA demonstrated statistically significant differences between the tested groups (ANOVA: F(3,32) = 14.05, p b 0.0001). The spontaneous locomotor activity was not modified by injections of ifenprodil and L-701,324, given in combination or separately (Table 1).

3.4. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of MK-801 on the immobility time in the FST in mice Fig. 4 illustrates the effect of sub-therapeutic dose of ifenprodil when given together with a sub-therapeutic dose of MK-801. Combination of these substances lead to a significant anti-immobility effect in the FST in mice, with the following statistics: F(3,35) = 7.083, p = 0.0008. As presented in Table 1, co-treatment of ifenprodil and MK-801 significantly stimulated locomotion of the mice between the 2nd and the 6th minute of the experiment in comparison to a single administration of ifenprodil; however the locomotion was not considerably changed in relation to the vehicle-treated group.

(B) Saline IF (10 mg/kg) DCS (2.5 mg/kg) IF/DCS

(C) Saline IF (10 mg/kg) L-701,324 (1 mg/kg) IF/L-701,324

(D) Saline IF (10 mg/kg) MK-801 (0.05 mg/kg) IF/MK-801

(E) Saline IF (10 mg/kg) Mg (10 mg/kg) IF/Mg

(F) Saline IF (10 mg/kg) Zn (2.5 mg/kg) IF/Zn

(G) Saline IF (20 mg/kg) NMDA (75 mg/kg) IF/NMDA

(H) Saline IF (20 mg/kg) DS (100 nmol/mouse) IF/DS

Activity counts between the 2nd and the 6th minute 764.5 ± 83.45 658.1 ± 61.00 929.1 ± 61.83 487.5 ± 77.77^^^ F(3,28) = 6.693, p = 0.0015 ^^^p b 0.001 versus CGP 37849 764.5 ± 83.45 658.1 ± 61.00 658.3 ± 121.7 530.4 ± 49.68 F(3,28) = 1.313, p = 0.2899

799.4 ± 24.85 604.8 ± 69.71 668.4 ± 86.36 622.9 ± 114.0 F(3,28) = 1.190, p = 0.3313

799.4 ± 24.85 604.8 ± 69.71 879.9 ± 87.28 870.8 ± 79.86 * F(3,28) = 3.355, p = 0.0329 *p b 0.05 versus IF 805.9 ± 130.4 605.9 ± 109.5 779.9 ± 92.92 339.1 ± 102.9 ^ F(3,28) = 3.832, p = 0.0204 ^p b 0.05 versus Mg 805.9 ± 130.4 605.9 ± 109.5 536.0 ± 66.72 319.3 ± 57.85 F(3,28) = 4.383, p = 0.0119

694.6 ± 105.4 559.3 ± 72.14 303.4 ± 52.25 * 396.1 ± 136.0 F(3,28) = 3.207, p = 0.0382 *p b 0.05 versus control 659.5 ± 163.3 546.3 ± 111.9 464.6 ± 107.8 229.8 ± 79.38 F(3,28) = 2.320, p = 0.0969

Data represent the mean ± SEM (n = 8 mice per group). Ifenprodil (IF), N-methyl-Daspartic acid (NMDA), CGP 37849, D-cycloserine (DCS), L-701,324, MK-801 and zinc hydroaspartate (Zn) were given 60 min before the experiment while magnesium hydroaspartate (Mg) and D-serine (DS) were injected 30 min and 15 min before the test, respectively. All solutions were administered i.p., except for DS which was administered i.c.v. Each animal in the experiments with DS was given an i.c.v. injection — either DS or vehicle, depending on the animal group. The data were evaluated by the one-way analysis of variance (ANOVA) followed by Student–Newman–Keuls post-hoc test.

3.5. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of magnesium hydroaspartate on the immobility time in the FST in mice The concomitant treatment with the sub-effective doses of ifenprodil and magnesium hydroaspartate exerted no influence on

32

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

Fig. 2. Effect of joint administration of ifenprodil (IF) and D-cycloserine (DCS) in the FST in mice. IF (10 mg/kg) and DCS (2.5 mg/kg) were administered i.p. 60 min before the test. The values represent the mean + SEM (n = 8–9 mice per group). ^^p b 0.01 versus DCS, *p b 0.05 versus IF and control (Student–Newman–Keuls post hoc test).

Fig. 4. Effect of joint administration of ifenprodil (IF) and MK-801 in the FST in mice. IF (10 mg/kg) and MK-801 (0.05 mg/kg) were administered i.p. 60 min before the test. The values represent the mean + SEM (n = 9–10 mice per group). ^p b 0.05 versus IF and MK-801, ***p b 0.001 versus control (Student–Newman–Keuls post hoc test).

the immobility time in the FST in mice (Fig. 5). One-way ANOVA did not demonstrate any significant differences between the tested groups (ANOVA: F(3,36) = 2.59, p = 0.0678). However, the joint administration of ifenprodil and magnesium hydroaspartate significantly decreased locomotor activity of the tested mice (Table 1), though the substances given alone did not affect the distance travelled by the animals.

p b 0.0001). The animals given NMDA travelled shorter distance than the control group. After concurrent use of NMDA and ifenprodil, no significant differences were found in relation to animals locomotion between the 2nd and the 6th minute of the experiment (Table 1).

3.6. Effect of the sub-effective dose of ifenprodil in combination with the sub-effective dose of zinc hydroaspartate on the immobility time in the FST in mice Similarly to the results obtained for combination of ifenprodil and magnesium hydroaspartate, the combination of sub-therapeutic doses of ifenprodil and zinc hydroaspartate produced no antidepressant-like effect in the FST in mice, which was illustrated in Fig. 6 (ANOVA: F(3,34) = 1.164, p = 0.3377). Relying on the outcomes presented in Table 1, none of the tested agents given alone significantly changed the locomotor activity between the 2nd and the 6th minute, as compared with to the vehicle-treated group. However, their combination markedly attenuated mice locomotion.

3.8. Effect of the effective dose of ifenprodil in combination with the subeffective dose of D-serine on the immobility time in the FST in mice Co-treatment of animals with ifenprodil and D-serine, drove the low ifenprodil-induced immobility time back to the control value (ANOVA: F(3,34) = 4.665, p = 0.0078) (Fig. 8). Compared with the vehicle-treated animals, ifenprodil given alone or in combination with D-serine did not affect the locomotor activity of mice, as presented in Table 1. 4. Discussion

As showed in Fig. 7, though a single 75 mg/kg dose of NMDA did not alter the immobility time of mice in the FST, it abolished the antidepressant-like effect elicited by ifenprodil injected at a dose of 20 mg/kg. One-way ANOVA pointed at a statistically significant differences between the tested groups (ANOVA: F(3,35) = 12.05,

To our knowledge it is the first complex study demonstrating in the FST in mice the effect of interactions between ifenprodil, a cerebral vasodilator, and the NMDA receptor agonists or antagonists acting at the discrete binding sites, given at the ineffective concentrations. Though affinity of ifenprodil for adrenergic, histamine and serotonin receptors as well as for calcium channels and sigma binding sites has been found (Contreras et al., 1990; Hashimoto and London, 1993, 1995), this compound is broadly used as a research tool to study properties of the NMDA receptor complex (Williams, 2009). Initially, ifenprodil was considered as a competitive antagonist acting at the neuromodulatory polyamine site of the NMDA receptor. In light of new researches, it appeared to be a negative modulator that

Fig. 3. Effect of joint administration of ifenprodil (IF) and L-701,324 in the FST in mice. IF (10 mg/kg) and L-701,324 (1 mg/kg) were administered i.p. 60 min before the test. The values represent the mean + SEM (n = 8–10 mice per group). ***p b 0.001 versus IF, and L-701,324 and control (Student–Newman–Keuls post hoc test).

Fig. 5. Effect of joint administration of ifenprodil (IF) and magnesium hydroaspartate (Mg) in the FST in mice. IF (10 mg/kg) and Mg (10 mg/kg) were administered i.p. 60 and 30 min before the test, respectively. The values represent the mean + SEM (n = 9–10 mice per group).

3.7. Effect of the effective dose of ifenprodil in combination with the sub-effective dose of NMDA on the immobility time in the FST in mice

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

Fig. 6. Effect of joint administration of ifenprodil (IF) and zinc hydroaspartate (Zn) in the FST in mice. IF (10 mg/kg) and Zn (2.5 mg/kg) were administered i.p. 60 before the test, respectively. The values represent the mean + SEM (n = 9–10 mice per group).

selectively binds to the NR1/NR2B receptor subtype, exerting the neuroprotective activity (Williams, 2009). According to literature data, low and non-effective doses of ifenprodil and paroxetine given concurrently produced a significant antidepressant-like effect in the FST (Ghasemi et al., 2009). Similarly, several other studies have shown that low doses of NMDA receptor antagonists administered simultaneously with certain antidepressants such as imipramine, citalopram or fluoxetine considerably diminished the immobility time of animals in the FST; such an effect was not accompanied by the rise in animal locomotion (Maj et al., 1992a, 1992b; Poleszak et al., 2011; Pruus et al., 2010; Rogóż et al., 2002, 2004). In the present work, the sub-effective dose of ifenprodil (10 mg/kg) administered concomitantly with also non-effective doses of the NMDA receptor antagonists (MK-801, CGP 37849, L-701,324) or a partial agonist of a glycine recognition site (D-cycloserine) significantly shortened the total duration of immobility of mice placed in an inescapable situation in the FST. These outcomes indicate that ifenprodil and the above-mentioned substances may act in synergy to produce the antidepressant-like effect. Since combination of the agents did not increase the spontaneous locomotor activity of animals (even attenuated it for in case of ifenprodil plus CGP 37849, Mg or Zn), their antiimmobility effect could not be attributed to the hypothetical psychostimulating properties. The obtained results are generally in line with previous findings which have shown that the tested substances at active or sub-active doses had no effect on the locomotion of animals (Ghasemi et al., 2009; Poleszak et al., 2007a; Trullas and Skolnick, 1990). However, the reduction in immobility induced by higher doses of MK-801 may partially results from the simultaneous

Fig. 7. Effect of joint administration of ifenprodil (IF) and N-methyl-D-aspartic acid (NMDA) in the FST in mice. IF (20 mg/kg) and NMDA (75 mg/kg) were administered i.p. 60 min before the test. The values represent the mean + SEM (n = 9–10 mice per group). ***p b 0.001 versus control, ^^^p b 0.001 versus IF (Student–Newman– Keuls post hoc test).

33

Fig. 8. Effect of joint administration of ifenprodil (IF) and D-serine (DS) in the FST in mice. IF (20 mg/kg) was administered i.p. 60 min before the test and DS (100 nmol/mouse) was given i.c.v. 15 min before the test. Each animal in the experiments with DS was given an i.c.v. injection — either DS or vehicle, depending on the tested group. The values represent the mean + SEM (n = 9–11 mice per group). *p b 0.05 versus control, ^^p b 0.01 versus IF (Student–Newman–Keuls post hoc test).

stimulation of locomotor activity (Dhir and Kulkarni, 2008). Maj et al. (1992b) observed that MK-801 at a dose of 0.1 mg/kg both shortened the total duration of animal immobility and increased their locomotion. In the present work, the mice given MK-801 alone or in combination with ifenprodil travelled considerably longer distance than animals treated solely with ifenprodil; though, these differences were not recorded in relation to the control group receiving saline. CGP 37849 at a dose of 0.03 mg/kg stimulated locomotion of animals in comparison with 10 mg/kg of ifenprodil. However, when both agents were given together, the activity of mice fell far below the level registered for the saline-treated group. Lack of the synergistic interaction between ifenprodil and divalent cations of zinc and magnesium observed in our study may be explained by the specificity of ifenprodil-magnesium/zinc interplay. As the literature data suggest (Coughenour and Barr, 2001), magnesium selectively decreases polyamine-sensitive ifenprodil binding to the NMDA receptor, while zinc diminishes ifenprodil binding to both the NMDA and sigma sites. Even though 2.5 mg/kg of zinc was not enough to affect mice locomotion, reduction of animal spontaneous locomotor activity by zinc has been found by other authors (Rosa et al., 2003). Only the co-treatment of ifenprodil with zinc resulted in significant shortening of distance travelled by the tested mice. Similar considerable attenuation of locomotion was noted after simultaneous acute therapy with ifenprodil and magnesium. Both tested cations (zinc and magnesium) are undoubtedly involved in the mechanisms of depression, since their decreased levels were detected in depressed patients (e.g. Eby et al., 2011; Maes et al., 1997; Siwek et al., 2010). Effective antidepressant therapy restored normal zinc and magnesium concentrations. Moreover, preparations containing these elements were efficacious as an adjunctive therapy in depressives (Eby and Eby, 2006; Eby et al., 2011; Nowak et al., 2003, 2005; Siwek et al., 2009). Somewhat in disagreement with our results, the antidepressant effects of magnesium or zinc were previously reinforced by D-cycloserine (a neurotransmitter which at the low doses mimics the action of endogenous glycine while at the high doses antagonises the glycine site). Similar enhancement of the anti-immobility activity of magnesium and zinc ions has been noted after the combined administration with other NMDA receptor antagonist (Poleszak et al., 2007a; Szewczyk et al., 2010) as well as with imipramine, citalopram and tianeptine (Poleszak et al., 2005; Poleszak, 2007; Rosa et al., 2003; Szewczyk et al., 2002, 2009). Though, the absence of synergistic or additive effect on the immobility of mice pre-treated with zinc chloride and then given MK-801 was reported by Rosa et al. (2003). Thorough reversal of ifenprodil antidepressant-like effect by an acute treatment with NMDA and D-serine further demonstrated the importance of NMDA receptor in the mechanism of anti-immobility action produced by this compound. Moreover, the presented data gave some

34

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35

additional evidences to the notion that the observed interactions between ifenprodil and the NMDA receptor inhibitors took place at the NMDA receptor level, at least partially. Both NMDA, an excitatory amino acid agonist several-fold weaker than (S)-glutamate, as well as D-serine, a co-agonist of the glycine binding site (Monaghan and Jane, 2009), injected in the sub-effective concentrations were previously reported to abolish the antidepressant-like effect of other NMDA receptor blockers, i.e. CGP 37849, L-701,324, magnesium and zinc (Poleszak et al., 2007b, 2008; Szewczyk et al., 2010). Moreover, D-serine pre-treatment reversed the antidepressant activity of imipramine, fluoxetine and reboxetine (Poleszak et al., 2011). On the other hand, the addition of ifenprodil averted the NMDA-induced hypolocomotion of mice to the values observed for the control group. Similarly, a 20-min decrease in locomotion of mice that received NMDA at a dose of 25 mg/kg was observed in the studies carried out by Gimenez-Llort et al. (1996); then, the motor activity of animals moderately enhanced. The neural mechanisms underlying the observed effects remain to be determined, since it is widely known that multiple neurotransmitter systems are involved in the emotional behaviour. Therefore, the animal performance recorded in the studies might be a resultant of complex interactions between various systems. 5. Conclusions Our data provide further evidences for the interactions between compounds binding to the NR2B subunit and other NMDA receptor ligands in relation to their activity in the FST, the most widely used predictive animal model of the antidepressant effect. Antidepressant-like potential of the tested agents given concomitantly was either reinforced (in the case of both partial agonist and antagonists, except for magnesium and zinc) or reduced (in the case of conventional full agonists). Additional studies investigating the molecular and neural mechanisms responsible for these interactions need to be carried out. Acknowledgements This study was supported by Funds for Statutory Activity of Medical University of Lublin and Maria Curie-Skłodowska University, Lublin, Poland. References Berman RM, Cappiello A, Anand A, Oren DA, Heninger GR, Charney DS, et al. Antidepressant effects of ketamine in depressed patients. Biol Psychiatry 2000;47:351–4. Bhatt JM, Prakash A, Suryavanshi PS, Dravid SM. Effect of ifenprodil on GluN1/GluN2B N-methyl-D-aspartate receptor gating. Mol Pharmacol 2013;83:9–21. Contreras PC, Bremer ME, Gray NM. Ifenprodil and SL 82.0715 potently inhibit binding of [3H](+)-3-PPP to sigma binding sites in rat brain. Neurosci Lett 1990;116:190–3. Coughenour LL, Barr BM. Use of trifluoroperazine isolates a [(3)H]Ifenprodil binding site in rat brain membranes with the pharmacology of the voltage-independent ifenprodil site on N-methyl-D-aspartate receptors containing NR2B subunits. J Pharmacol Exp Ther 2001;296:150–9. Decollogne S, Tomas A, Lecerf C, Adamowicz E, Seman M. NMDA receptor complex blockade by oral administration of magnesium: comparison with MK-801. Pharmacol Biochem Behav 1997;58:261–8. Dhir A, Kulkarni SK. Possible involvement of nitric oxide (NO) signaling pathway in the antidepressant-like effect of MK-801(dizocilpine), a NMDA receptor antagonist in mouse forced swim test. Indian J Exp Biol 2008;46:164–70. Eby GA, Eby KL. Rapid recovery from major depression using magnesium treatment. Med Hypotheses 2006;67:362–70. Eby GA, Eby KL, Murck H. Magnesium and major depression. In: Vink R, Nechifor M, editors. Magnesium in the central nervous system. Adelaide: University of Adelaide Press; 2011. p. 313–30. Farlow MR. NMDA receptor antagonists. A new therapeutic approach for Alzheimer's disease. Geriatrics 2004;59:22–7. Ghasemi M, Montaser-Kouhsari L, Shafaroodi H, Nezami BG, Ebrahimi F, Dehpour AR. NMDA receptor/nitrergic system blockage augments antidepressant-like effects of paroxetine in the mouse forced swimming test. Psychopharmacology (Berl) 2009;206:325–33. Giménez-Llort L, Ferré S, De Vera N, Martínez E. Motor depressant effects of systemically administered polyamines in mice: involvement of central NMDA receptors. Eur J Pharmacol 1996;318:231–8.

Hashimoto K. Emerging role of glutamate in the pathophysiology of major depressive disorder. Brain Res Rev 2009;61:105–23. Hashimoto K, London ED. Further characterization of [3H]ifenprodil binding to sigma receptors in rat brain. Eur J Pharmacol 1993;236:159–63. Hashimoto K, London ED. Interactions of erythro-ifenprodil, threo-ifenprodil, erythroiodoifenprodil, and eliprodil with subtypes of sigma receptors. Eur J Pharmacol 1995;273:307–10. Kew JN, Trube G, Kemp JA. A novel mechanism of activity-dependent NMDA receptor antagonism describes the effect of ifenprodil in rat cultured cortical neurones. J Physiol 1996;497:761–72. Law AJ, Deakin JF. Asymmetrical reductions of hippocampal NMDAR1 glutamate receptor mRNA in the psychoses. Neuroreport 2001;12:2971–4. Lipman JJ, Spencer PS. Rapid intracerebroventricular injection assisted by an automatic syringe. J Pharmacol Methods 1980;4:327–33. Lopes T, Neubauer P, Boje KM. Chronic administration of NMDA glycine partial agonists induces tolerance in the Porsolt swim test. Pharmacol Biochem Behav 1997;58:1059–64. Maes M, Vandoolaeghe E, Neels H, Demedts P, Wauters A, Meltzer HY, et al. Lower serum zinc in major depression is a sensitive marker of treatment resistance and of the immune/inflammatory response in that illness. Biol Psychiatry 1997;42:349–58. Maj J, Rogóż Z, Skuza G. The effects of combined treatment with MK-801 and antidepressant drugs in the forced swimming test in rats. Pol J Pharmacol Pharm 1992a;44:217–26. Maj J, Rogóż Z, Skuza G, Sowińska H. Effects of MK-801 and antidepressant drugs in the forced swimming test in rats. Eur Neuropsychopharmacol 1992b;2:37–41. Maj J, Rogóż Z, Skuza G, Sowińska H. The effect of CGP 37849 and CGP 39551, competitive NMDA receptor antagonists, in the forced swimming test. Pol J Pharmacol Pharm 1992c;44:337–46. Monaghan DT, Jane DE. Pharmacology of NMDA receptors. In: Van Dongen AM, editor. Frontiers in Neuroscience. Boca Raton (FL): CRC Press, North Carolina; 2009. Mony L, Zhu S, Carvalho S, Paoletti P. Molecular basis of positive allosteric modulation of GluN2B NMDA receptors by polyamines. EMBO J 2011;30:3134–46. Nowak G, Siwek M, Dudek D, Zięba A, Pilc A. Effect of zinc supplementation on antidepressant therapy in unipolar depression: a preliminary placebo-controlled study. Pol J Pharmacol 2003;55:1143–7. Nowak G, Szewczyk B, Pilc A. Zinc and depression. An update. Pharmacol Rep 2005;57:713–8. Petit-Demouliere B, Chenu F, Bourin M. Forced swimming test in mice: a review of antidepressant activity. Psychopharmacology (Berl) 2005;177:245–55. Poleszak E. Modulation of antidepressant-like activity of magnesium by serotonergic system. J Neural Transm 2007;114:1129–34. Poleszak E, Wlaź P, Szewczyk B, Kędzierska E, Wyska E, Librowski T, et al. Enhancement of antidepressant-like activity by joint administration of imipramine and magnesium in the forced swim test: behavioral and pharmacokinetic studies in mice. Pharmacol Biochem Behav 2005;81:524–9. Poleszak E, Wlaź P, Kędzierska E, Nieoczym D, Wróbel A, Fidecka S, et al. NMDA/glutamate mechanism of antidepressant-like action of magnesium in forced swim test in mice. Pharmacol Biochem Behav 2007a;88:158–64. Poleszak E, Wlaź P, Wróbel A, Dybała M, Sowa M, Fidecka S, et al. Activation of the NMDA/glutamate receptor complex antagonizes the NMDA antagonist-induced antidepressant-like effects in the forced swim test. Pharmacol Rep 2007b;59:595–600. Poleszak E, Szewczyk B, Wlaź A, Fidecka S, Wlaź P, Pilc A, et al. D-serine, a selective glycine/N-methyl-D-aspartate receptor agonist, antagonizes the antidepressantlike effects of magnesium and zinc in mice. Pharmacol Rep 2008;60:996–1000. Poleszak E, Wlaź P, Szewczyk B, Wlaź A, Kasperek R, Wróbel A, et al. A complex interaction between glycine/NMDA receptors and serotonergic/noradrenergic antidepressants in the forced swim test in mice. J Neural Transm 2011;118:1535–46. Porsolt RD, Bertin A, Jalfre M. Behavioral despair in mice: a primary screening test for antidepressants. Arch Int Pharmacodyn Ther 1977;229:327–36. Preskorn SH, Baker B, Kolluri S, Menniti FS, Krams M, Landen JW. An innovative design to establish proof of concept of the antidepressant effects of the NR2B subunit selective N-methyl-D-aspartate antagonist, CP-101,606, in patients with treatmentrefractory major depressive disorder. J Clin Psychopharmacol 2008;28:631–7. Pruus K, Rudissaar R, Allikmets L, Harro J. The effect of the NMDA receptor antagonist dizocilpine on behavioral manifestations of serotonin and adrenergic antidepressants in rats. Methods Find Exp Clin Pharmacol 2010;32:123–8. Rogóż Z, Skuza G, Maj J, Danysz W. Synergistic effect of uncompetitive NMDA receptor antagonists and antidepressant drugs in the forced swimming test in rats. Neuropharmacology 2002;42:1024–30. Rogóż Z, Skuza G, Kuśmider M, Wójcikowski J, Kot M, Daniel WA. Synergistic effect of imipramine and amantadine in the forced swimming test in rats. Behavioral and pharmacokinetic studies. Pol J Pharmacol 2004;56:179–85. Rosa AO, Lin J, Calixto JB, Santos AR, Rodrigues AL. Involvement of NMDA receptors and L-arginine–nitric oxide pathway in the antidepressant-like effects of zinc in mice. Behav Brain Res 2003;144:87–93. Sanacora G, Gueorguieva R, Epperson CN, Wu YT, Appel M, Rothman DL, et al. Subtype-specific alterations of gamma-aminobutyric acid and glutamate in patients with major depression. Arch Gen Psychiatry 2004;61:705–13. Siwek M, Dudek D, Paul IA, Sowa-Kućma M, Zięba A, Popik P, et al. Zinc supplementation augments efficacy of imipramine in treatment resistant patients: a double blind, placebo-controlled study. J Affect Disord 2009;118:187–95. Siwek M, Dudek D, Schlegel-Zawadzka M, Morawska A, Piekoszewski W, Opoka W, et al. Serum zinc level in depressed patients during zinc supplementation of imipramine treatment. J Affect Disord 2010;126:447–52. Szewczyk B, Brański P, Wierońska JM, Palucha A, Pilc A, Nowak G. Interaction of zinc with antidepressants in the forced swimming test in mice. Pol J Pharmacol 2002;54:681–5. Szewczyk B, Poleszak E, Wlaź P, Wróbel A, Blicharska E, Cichy A, et al. The involvement of serotonergic system in the antidepressant effect of zinc in the forced swim test. Prog Neuropsychopharmacol Biol Psychiatry 2009;33:323–9.

E. Poleszak et al. / Progress in Neuro-Psychopharmacology & Biological Psychiatry 46 (2013) 29–35 Szewczyk B, Poleszak E, Sowa-Kućma M, Wróbel A, Słotwiński S, Listos J, et al. The involvement of NMDA and AMPA receptors in the mechanism of antidepressant-like action of zinc in the forced swim test. Amino Acids 2010;39: 205–17. Traynelis SF, Wollmuth LP, McBain CJ, Menniti FS, Vance KM, Ogden KK, et al. Glutamate receptor ion channels: structure, regulation, and function. Pharmacol Rev 2010;62:405–96. Tricklebank MD, Singh L, Oles RJ, Preston C, Iversen SD. The behavioural effects of MK-801: a comparison with antagonists acting non-competitively and competitively at the NMDA receptor. Eur J Pharmacol 1989;167:127–35. Trullas R, Skolnick P. Functional antagonists at the NMDA receptor complex exhibit antidepressant actions. Eur J Pharmacol 1990;185:1–10. Wędzony K, Klimek V, Nowak G. Rapid down-regulation of beta-adrenergic receptors evoked by combined forced swimming test and CGP 37849—a competitive antagonist of NMDA receptors. Pol J Pharmacol 1995;47:537–40.

35

Willetts J, Balster RL, Leander JD. The behavioral pharmacology of NMDA receptor antagonists. Trends Pharmacol Sci 1990;11:423–8. Williams K. Extracellular modulation of NMDA receptors. In: Van Dongen AM, editor. Biology of the NMDA receptor. CRC Press; 2009. Willner P, Scheel-Kruger J, Belzung C. The neurobiology of depression and antidepressant action. Neurosci Biobehav Rev 2012. http://dx.doi.org/10.1016/j.neubiorev.2012.12.007. Wlaź P, Kasperek R, Wlaź A, Szumiło M, Wróbel A, Nowak G, et al. NMDA and AMPA receptors are involved in the antidepressant-like activity of tianeptine in the forced swim test in mice. Pharmacol Rep 2011;63:1526–32. Zarate Jr CA, Singh JB, Carlson PJ, Brutsche NE, Ameli R, Luckenbaugh DA, et al. A randomized trial of an N-methyl-D-aspartate antagonist in treatment-resistant major depression. Arch Gen Psychiatry 2006a;63:856–64. Zarate Jr CA, Singh JB, Quiroz JA, De JG, Denicoff KK, Luckenbaugh DA, et al. A double-blind, placebo-controlled study of memantine in the treatment of major depression. Am J Psychiatry 2006b;163:153–5.