Female Japanese quail with high levels of estradiol demonstrate cocaine-induced conditioned place preference

Study on the antidepressant activity of (2R,6R; 2S,6S)-Hydroxynorketamine (HNK) and its derivatives

OBJECTIVE

This study mainly explores (2R,6R; 2S,6S)-HNK and its compounds whether there are antidepressant effects.

METHODS

Four HNK compounds were obtained from 2-(Chlorophenyl) Cyclopentylmethanone. Forced swimming test, locomotor sensitization test, and conditioned location preference test were used to screen the antidepressant activity of the synthesized target compounds.

RESULTS

In the case of 10 mg HNK treatment, compared with saline, the immobile time of mice in the HNK group, I5 group and I6 group at 1 h and 7 days had statistical significance. In the case of 10 mg HNK treatment, compared with saline, the immobile time of compound C and D groups in the glass cylinder area was significantly different. In the locomotor sensitization test, the movement distance of compound C and D groups on day 15 and day 7 mice increased significantly compared with the first day. In the conditioned place preference experiment, compound C and compound D induced conditioned place preference in mice compared with the Veh group.

CONCLUSION

The results of the forced swimming test, locomotor sensitization test, and conditioned location preference test showed that compounds C and D may have certain anti-depressant activity. However, HNK exerts a rapid and significant antidepressant effect within 1 week, but the duration is short.

Conditioned preferences: Gated by experience, context, and endocrine systems

Central to the navigation of an ever-changing environment is the ability to form positive associations with places and conspecifics. The functions of location and social conditioned preferences are often studied independently, limiting our understanding of their interplay. Furthermore, a de-emphasis on natural functions of conditioned preferences has led to neurobiological interpretations separated from ecological context. By adopting a naturalistic and ethological perspective, we uncover complexities underlying the expression of conditioned preferences. Development of conditioned preferences is a combination of motivation, reward, associative learning, and context, including for social and spatial environments. Both social- and location-dependent reward-responsive behaviors and their conditioning rely on internal state-gating mechanisms that include neuroendocrine and hormone systems such as opioids, dopamine, testosterone, estradiol, and oxytocin. Such reinforced behavior emerges from mechanisms integrating past experience and current social and environmental conditions. Moreover, social context, environmental stimuli, and internal state gate and modulate motivation and learning via associative reward, shaping the conditioning process. We highlight research incorporating these concepts, focusing on the integration of social neuroendocrine mechanisms and behavioral conditioning. We explore three paradigms: 1) conditioned place preference, 2) conditioned social preference, and 3) social conditioned place preference. We highlight nonclassical species to emphasize the naturalistic applications of these conditioned preferences. To fully appreciate the complex integration of spatial and social information, future research must identify neural networks where endocrine systems exert influence on such behaviors. Such research promises to provide valuable insights into conditioned preferences within a broader naturalistic context.

PT150 blocks the rewarding properties of ethanol and attenuates ethanol-induced reduction of egg laying in Coturnix quail

RATIONALE

Alcohol use disorder (AUD) has been shown to be associated with a dysregulated stress system. Reducing the stress hormone corticosterone (CORT), that binds to glucocorticoid receptors, may attenuate the rewarding properties of drugs of abuse. However, the effect of blocking corticosterone receptors on ethanol reward has yet to be investigated.

OBJECTIVES

The current study investigated whether the stress hormone receptor antagonist, PT150, would block the rewarding properties of ethanol via the glucocorticoid receptor system and attenuate other ethanol-induced effects.

METHODS

A conditioned place preference (CPP) procedure was used to examine the rewarding properties of ethanol in an avian preclinical model. Ethanol was paired with the least preferred chamber. On alternate days, water was paired with the preferred chamber. After eight pairings, a place preference test was given that allowed subjects to have access to both chambers. Half of the subjects received PT150 prior to ethanol administration. The other half received vehicle. Time spent in each chamber during the preference tests, locomotor activity during the pairings, and egg production in female birds was recorded.

RESULTS

Ethanol treatment resulted in a CPP and pretreatment of PT150 blocked the acquisition of the ethanol-induced place preference. Neither ethanol nor PT150 altered locomotor activity. Pretreatment of PT150 also increased egg production in female quail treated with ethanol.

CONCLUSIONS

These findings suggest repeated ethanol pairings with visual cues can produce a CPP. Furthermore, pretreatment of PT150 may be a potential pharmacotherapy for blocking the rewarding properties of ethanol and may enhance egg production in female quail treated with ethanol.

Ethanol induces a dose-dependent conditioned place preference and conditioned place aversion in Japanese quail

The conditioned place preference (CPP) paradigm is commonly used to investigate the motivational properties of drugs of abuse. Cues in the environment may become paired with these motivational properties and later result in drug seeking. Because many of these alcohol-paired cues are visual, Japanese quail may be a beneficial model to examine visual cue-induced alcohol seeking behavior. The aim of the present study was to examine the motivational properties of ethanol using a visual CPP model. During CPP, quail were given an initial preference test to determine their initially preferred chamber, during which time they could explore the entire chamber for 15 min. Following the initial preference test, quail were gavaged with their assigned treatment (water or 0.75 or 2.0 g/kg of ethanol) and were confined to their initially least preferred chamber every other conditioning day for 30 min. On alternate days, they were gavaged with water and confined to the preferred chamber for 30 min. After the 8th day of conditioning, a final preference test was given. Locomotor activity was also measured during conditioning. The findings indicated that quail that received the 0.75 g/kg ethanol developed a place preference to the ethanol-paired chamber, and that quail treated with 2 g/kg ethanol developed a place aversion to the ethanol-paired chamber. Additionally, locomotor activity was reduced in quail that received the high dose of ethanol. The findings suggest that both the rewarding and aversive properties of ethanol may be observable in this visual cue CPP model. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

D2 receptor antagonism enhances cocaine-induced behavioral sensitization in female, but not male Japanese quail ( Coturnix japonica )

Sex differences in cocaine-induced behaviors are well established. In rodents, females show enhanced locomotion to cocaine over multiple trials compared with males, a behavioral response known as sensitization. Estradiol enhances cocaine-induced sensitization in female rats by agonizing dopaminergic activity within the brain. In female quail, cocaine does not increase locomotion regardless of increased estradiol. A higher D2:D1 dopamine receptor ratio in quail compared with rodents may explain this sex and species difference. The goal of the present work was to investigate the role of D2 receptors in cocaine-induced locomotion and sensitization in Japanese quail and to determine whether a greater D2 receptor availability contributed to the lack of cocaine-induced sensitization in female quail found in previous studies. Male and female quail were administered 0, 0.03, 0.05, or 0.07 mg/kg of eticlopride (Eti) followed by 10 mg/kg of cocaine or saline then immediately placed in open-field chambers. Distance traveled was recorded for 30 min daily for 7 days. In female quail, cocaine-induced sensitization was observed with 0.03 or 0.05 mg/kg Eti, but not in cocaine-only females. In male quail, cocaine-induced sensitization was observed similar to previous research. However, Eti did not enhance cocaine-induced locomotion or produce sensitization in male quail. The D2 receptor likely mediates cocaine's motor stimulating effects in quail. In females, this effect is more pronounced. Since high D2 availability is protective against stimulant abuse, Japanese quail may be a useful model for investigating the role of the D2 receptor in cocaine addiction, but further research is needed.

Association of LEPR polymorphisms with egg production and growth performance in female Japanese quails

This study aimed to screen intron 8 of the leptin receptor (LEPR) gene for polymorphisms in female Japanese quails. Two adjacent novel SNPs (A277G and A304G) were detected using PCR-SSCP and sequencing. These SNPs produced three haplotypes (AA/AA, AG/AG, and GG/GG) that were significantly (p ≤ 0.05) associated with growth and egg production traits. GG/GG haplotype-quails had significantly (p ≤ 0.05) lower egg production, feed intake, growth performance, lipid profile, serum levels of sex hormones (estradiol, progesterone, FSH, LH), and ovarian expressions of survivin, FSHR, and IGF1 than other quails. However, GG/GG quails had significantly (p ≤ 0.05) higher serum levels of LEP and mRNA levels of LEPR, LEP, and caspase 3 in the hypothalamus and ovaries. These higher levels of LEP/LEPR could not only reduce feed intake and body weight gain but also could induce apoptosis of ovarian cells (as indicated by lower survivin and IGF1 and higher caspase3 expression) which could inhibit the development of the follicles and the release of sex hormones with a subsequent decrease in egg production in GG/GG quails. Therefore, with these results, we suggest selecting Japanese quails with AA/AA and AG/AG haplotypes to improve the reproduction and growth performance of this flock.