scholarly journals Maternal Separation Stress Affects Voluntary Ethanol Intake in a Sex Dependent Manner

2021 ◽  
Vol 12 ◽  
Author(s):  
Natalia Bonetti Bertagna ◽  
Cristiane Aparecida Favoretto ◽  
Ben Tagami Rodolpho ◽  
Paola Palombo ◽  
Thais Suemi Yokoyama ◽  
...  
Keyword(s):  
Maternal Separation ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Ethanol Consumption ◽  
Ethanol Intake ◽  
Central Nucleus ◽  
Control Group ◽  
Dependent Manner ◽  
Self Administration ◽  
Extended Amygdala

Maternal separation (MS) stress is a predictive animal model for evaluating the effects of early stress exposure on alcohol use disorders (AUD). The extended amygdala (AMY) is a complex circuit involved in both stress- and ethanol-related responses. We hypothesized that MS stress may increase ethanol consumption in adulthood, as well as augment neuronal activity in extended AMY, in a sex-dependent manner. We aimed to investigate the influence of MS stress on the ethanol consumption of male and female mice, and the involvement of extended amygdala sub-nuclei in this process. The C57BL/6J pups were subjected to 180min of MS, from postnatal day (PND) 1 to 14. The control group was left undisturbed. On PND 45, mice (n=28) in cages were exposed to a bottle containing 20% ethanol (w/v) for 4h during the dark period of the light-dark cycle, for 3weeks. Afterward, mice underwent ethanol self-administration training in operant chambers under fixed ratio (FR) schedule. Then, subjects were tested under 2h sessions of a progressive-ratio (PR) schedule of reinforcement (the last ratio achieved was considered the breaking point), and at the end, a 4h session of FR schedule (binge-intake). An immunohistochemistry assay for Fos protein was performed in Nucleus Accumbens (NAcc), Bed Nucleus of Stria Terminalis (BNST), and AMY. Our results showed that in the third week of training, the female MS group consumed more ethanol than the respective control group. The MS group presented increased breakpoint parameters. Female control group and male MS group were more resistant to bitter quinine taste. Increased Fos-immunoreactive neurons (Fos-IR) were observed in the central nucleus of AMY, but not in NAcc nor BNST in male maternal-separated mice. Maternal separation stress may influence ethanol intake in adulthood, and it is dependent on the sex and reinforcement protocol.

scholarly journals Ethanol-Related Behaviors in Mouse Lines Selectively Bred for Drinking to Intoxication

2021 ◽  
Vol 11 (2) ◽  
pp. 189
Author(s):  
Bryan E. Jensen ◽  
Kayla G. Townsley ◽  
Kolter B. Grigsby ◽  
Pamela Metten ◽  
Meher Chand ◽  
...  
Keyword(s):  
Drinking Behavior ◽  
Effective Means ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Blood Alcohol ◽  
Drinking Patterns ◽  
Self Administration ◽  
Blood Alcohol Levels ◽  
Drinking In The Dark ◽  
Mouse Lines

Alcohol use disorder (AUD) is a devastating psychiatric disorder that has significant wide-reaching effects on individuals and society. Selectively bred mouse lines are an effective means of exploring the genetic and neuronal mechanisms underlying AUD and such studies are translationally important for identifying treatment options. Here, we report on behavioral characterization of two replicate lines of mice that drink to intoxication, the High Drinking in the Dark (HDID)-1 and -2 mice, which have been selectively bred (20+ generations) for the primary phenotype of reaching high blood alcohol levels (BALs) during the drinking in the dark (DID) task, a binge-like drinking assay. Along with their genetically heterogenous progenitor line, Hs/Npt, we tested these mice on: DID and drinking in the light (DIL); temporal drinking patterns; ethanol sensitivity, through loss of righting reflex (LORR); and operant self-administration, including fixed ratio (FR1), fixed ratio 3:1 (FR3), extinction/reinstatement, and progressive ratio (PR). All mice consumed more ethanol during the dark than the light and both HDID lines consumed more ethanol than Hs/Npt during DIL and DID. In the dark, we found that the HDID lines achieved high blood alcohol levels early into a drinking session, suggesting that they exhibit front loading like drinking behavior in the absence of the chronicity usually required for such behavior. Surprisingly, HDID-1 (female and male) and HDID-2 (male) mice were more sensitive to the intoxicating effects of ethanol during the dark (as determined by LORR), while Hs/Npt (female and male) and HDID-2 (female) mice appeared less sensitive. We observed lower HDID-1 ethanol intake compared to either HDID-2 or Hs/Npt during operant ethanol self-administration. There were no genotype differences for either progressive ratio responding, or cue-induced ethanol reinstatement, though the latter is complicated by a lack of extinguished responding behavior. Taken together, these findings suggest that genes affecting one AUD-related behavior do not necessarily affect other AUD-related behaviors. Moreover, these findings highlight that alcohol-related behaviors can also differ between lines selectively bred for the same phenotype, and even between sexes within those same line.

2Hz-Electroacupuncture Attenuates Conditioned Cue-Evoked Heroin-Seeking Behavior and Increase CB2-Rs Expression in Relapse-Relevant Brain Regions in Heroin-Addicted Rats

2014 ◽  
Vol 998-999 ◽  
pp. 164-168 ◽  
Author(s):  
Lin Chen ◽  
Bao Miao Ma ◽  
Kai Yue ◽  
Qin Ru ◽  
Xiang Tian ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Nucleus Accumbens ◽  
Rat Model ◽  
Fixed Ratio ◽  
Brain Regions ◽  
Inhibitory Effect ◽  
Control Group ◽  
Self Administration ◽  
Seeking Behavior

In order to investigate the influence of electroacupuncture on heroin seeking behavior and the expression of CB2-Rs in the relapse-relevant brain regions, heroin self-administration rat model which represents the heroin relapse behaviors was developed with progressive fixed ratio program. The model rats were randomly divided into 3 groups: control group, heroin-addicted group and 2Hz electroacupuncture group (stimulating on acupoints zusanli and sanyinjiao). The expression of CB2-Rs in the relapse-relevant brain regions were assessed with immunohistochemistry technologies. The reinstatement of heroin seeking behavior induced by conditioned cue priming showed that compared with the heroin-addicted group, active pokes in the 2Hz electroacupuncture group decreased significantly (p<0.05). Compared with the control group, the expression of CB2-Rs in prefrontal cortex (PFC) and nucleus accumbens (NAc) was significantly decreased (p<0.05) in heroin-addicted group and increaseed significantly recover (p<0.05) in the 2Hz electroacupuncture group. Our present results showed that 2Hz-electroacupuncture could attenuate the conditioned cue-evoked heroin-seeking behavior and the inhibitory effect was mediated partially by the increase CB2-Rs expression in relapse-relevant brain regions in heroin-addicted rats.

scholarly journals Dramatic increase in lever-pressing activity in rats after training on the progressive ratio schedule of cocaine self-administration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vladimir L. Tsibulsky ◽  
Andrew B. Norman
Keyword(s):  
Fixed Ratio ◽  
Progressive Ratio ◽  
Ratio Schedule ◽  
Self Administration ◽  
The Press ◽  
Second Mode ◽  
Before And After ◽  
Lever Pressing ◽  
Remission Phase ◽  
Definition Of

AbstractTransition from the highest rate of lever-pressing activity during the unloading (extinction) phase of a cocaine self-administration session to an extremely low activity rate during the remission phase is in many cases gradual. This makes it difficult to assess the duration of the unloading phase after a fixed ratio 1 (FR1) or breakpoint after a progressive-ratio (PR) self-administration session. In addition, 3–5 days of training under the PR schedule results in a dramatic and persistent increase in the rate of presses during PR sessions and in the unloading phase following FR1 self-administration sessions. The goals of this study were to find the definition of the last press demarcating the border between the unloading and remission phases of the session and to determine if this border was also affected by PR training. Rats were trained to self-administer cocaine under the FR1 schedule and then under the PR schedule of drug delivery. Distributions of inter-press intervals (IPIs) during the unloading phase in sessions before and after PR training were compared. It was found that the distribution of cocaine-induced IPIs during the unloading phase was lognormal, bimodal, and independent of previously injected cocaine unit doses. The first mode represented intervals within the short bouts of stereotypic presses and the second mode represented intervals between bouts. The two modes were approximately 0.7 s and 21 s during unloading prior to and 0.6 s and 1.5 s after PR self-administration training. The total number of presses per unloading phase increased eightfold. When the FR1 schedule was restored, the intervals between bouts remained very short for at least 7–10 days and only then started a gradual increase towards baseline levels. The last unloading press was defined as the press followed by the IPI longer than the defined criterion. PR training resulted in a substantial and long-lasting increase in lever-pressing activity during unloading. The duration of the unloading phase did not depend on the rate of lever-pressing activity.

The dopamine β-hydroxylase inhibitor, nepicastat, suppresses chocolate self-administration and reinstatement of chocolate seeking in rats

2013 ◽  
Vol 110 (8) ◽  
pp. 1524-1533 ◽  
Author(s):  
Alessandro Zaru ◽  
Paola Maccioni ◽  
Giancarlo Colombo ◽  
Gian Luigi Gessa
Keyword(s):  
Fixed Ratio ◽  
Progressive Ratio ◽  
Schedules Of Reinforcement ◽  
Self Administration ◽  
Pharmacological Agents ◽  
New Class ◽  
Cocaine Seeking ◽  
Reinforcement Measures ◽  
Food Seeking ◽  
Prevention Of Relapse

Craving for chocolate is a common phenomenon, which may evolve to an addictive-like behaviour and contribute to obesity. Nepicastat is a selective dopamine β-hydroxylase (DBH) inhibitor that suppresses cocaine-primed reinstatement of cocaine seeking in rats. We verified whether nepicastat was able to modify the reinforcing and motivational properties of a chocolate solution and to prevent the reinstatement of chocolate seeking in rats. Nepicastat (25, 50 and 100 mg/kg, intraperitoneal) produced a dose-related inhibition of operant self-administration of the chocolate solution in rats under fixed-ratio 10 (FR10) and progressive-ratio schedules of reinforcement, measures of the reinforcing and motivational properties of the chocolate solution, respectively. The effect of nepicastat on the reinstatement of chocolate seeking was studied in rats in which lever-responding had been extinguished by removing the chocolate solution for approximately 8 d. Nepicastat dose-dependently suppressed the reinstatement of lever-responding triggered by a ‘priming’ of the chocolate solution together with cues previously associated with the availability of the reward. In a separate group of food-restricted rats trained to lever-respond for regular food pellets, nepicastat reduced FR10 lever-responding with the same potency as for the chocolate solution. Spontaneous locomotor activity was not modified by nepicastat doses that reduced self-administration of the chocolate solution and regular food pellets and suppressed the reinstatement of chocolate seeking. The results indicate that nepicastat reduces motivation to food consumption sustained by appetite or palatability. Moreover, the results suggest that DBH inhibitors may be a new class of pharmacological agents potentially useful in the prevention of relapse to food seeking in human dieters.

scholarly journals Knockdown of Hypocretin/Orexin Attenuates Extended-Access Cocaine Self-Administration in Rats

2017 ◽  
Author(s):  
Brooke E. Schmeichel ◽  
Alessandra Matzeu ◽  
Pascale Koebel ◽  
Leandro F. Vendruscolo ◽  
Brigitte L. Kieffer ◽  
...  
Keyword(s):  
Stress Responses ◽  
Viral Vector ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Ratio Schedule ◽  
Self Administration ◽  
Adult Rats ◽  
Extended Access ◽  
Seeking Behavior ◽  
Melanin Concentrating Hormone

AbstractThe hypocretin/orexin (HCRT) neuropeptide system regulates feeding, arousal state, stress responses, and reward, especially under conditions of enhanced motivational relevance. In particular, HCRT neurotransmission facilitates drug-seeking behavior in circumstances that demand increased effort and/or motivation to take the drug. The present study used a shRNA-encoding adeno-associated viral vector to knockdown Hcrt expression throughout the dorsal hypothalamus in adult rats and determine the role of HCRT in cocaine self-administration. Longterm Hcrt silencing did not impact cocaine self-administration under short-access conditions, but robustly attenuated cocaine intake during extended self-administration access, a model that mimics key features of compulsive cocaine-taking. In addition, Hcrt silencing decreased motivation for both cocaine and palatable food (i.e., sweetened condensed milk; SCM) under a progressive ratio schedule of reinforcement, but did not alter responding for SCM under a fixed ratio schedule. Importantly, Hcrt silencing did not affect food or water consumption, and had no consequence to general measures of arousal-dependent behaviors. At the molecular level, longterm Hcrt knockdown moderately reduced the downstream expression of dynorphin (DYN) and melanin-concentrating hormone (MCH) in the dorsal hypothalamus. These original findings support the hypothesis that HCRT neurotransmission promotes operant responding for both drug and non-drug rewards, preferentially under conditions requiring a high degree of motivation. Furthermore, the current study provides compelling evidence for the involvement of the HCRT system in cocaine self-administration also under low-effort conditions in rats allowed extended access, possibly via functional interactions with DYN and MCH signaling.

scholarly journals The Novel Positive Allosteric Modulator of the GABAB Receptor, KK-92A, Suppresses Alcohol Self-Administration and Cue-Induced Reinstatement of Alcohol Seeking in Rats

2021 ◽  
Vol 9 ◽  
Author(s):  
Paola Maccioni ◽  
Katarzyna Kaczanowska ◽  
Harshani Lawrence ◽  
Sang Yun ◽  
Jessica Bratzu ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Drugs Of Abuse ◽  
Gabab Receptor ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Spontaneous Locomotor Activity ◽  
Schedules Of Reinforcement ◽  
Self Administration ◽  
Motivated Behaviors ◽  
Alcohol Seeking

Positive allosteric modulators (PAMs) of the GABAB receptor (GABAB PAMs) are of interest in the addiction field due to their ability to suppress several behaviors motivated by drugs of abuse. KK-92A is a novel GABAB PAM found to attenuate intravenous self-administration of nicotine and reinstatement of nicotine seeking in rats. This present study was aimed at extending to alcohol the anti-addictive properties of KK-92A. To this end, Sardinian alcohol-preferring rats were trained to lever-respond for oral alcohol (15% v/v) or sucrose (0.7% w/v) under the fixed ratio (FR) 5 (FR5) schedule of reinforcement. Once lever-responding behavior had stabilized, rats were exposed to tests with acutely administered KK-92A under FR5 and progressive ratio schedules of reinforcement and cue-induced reinstatement of previously extinguished alcohol seeking. KK-92A effect on spontaneous locomotor activity was also evaluated. Treatment with 10 and 20 mg/kg KK-92A suppressed lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol. Treatment with 20 mg/kg KK-92A reduced sucrose self-administration. Combination of per se ineffective doses of KK-92A (2.5 mg/kg) and the GABAB receptor agonist, baclofen (1 mg/kg), reduced alcohol self-administration. Treatment with 5, 10, and 20 mg/kg KK-92A suppressed reinstatement of alcohol seeking. Only treatment with 80 mg/kg KK-92A affected spontaneous locomotor activity. These results demonstrate the ability of KK-92A to inhibit alcohol-motivated behaviors in rodents and confirm that these effects are common to the entire class of GABAB PAMs. The remarkable efficacy of KK-92A is discussed in terms of its ago-allosteric properties.

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