ABSTRACT
BACKGROUND: This review article integrates findings from published behavioural and neuroimaging studies of impulsive-compulsive behaviours (ICBs) in Parkinson's disease, with the aim of identifying the basic correlates of these problematic and distressing behaviours. The underlying premise is that for any feature to be a reliable marker of ICBs, it should be evident across multiple levels of analyses. When changes are evident only at one level, but not in the others, their reliability as indicators of ICBs should be questioned. SUMMARY: To this end, we draw on the conclusions from three published systematic reviews of dopamine metabolic processes in the striatum, functional magnetic resonance imaging and cognitive, affective, and motivational assessments of medicated Parkinson's patients with and without ICBs (ICB+ and ICB-, respectively). The key findings are as follows: ICB+ showed abnormal dopaminergic of the striatum, including the brain network supporting reward processing. Fronto-striatal connectivity was also reduced. These findings are consistent with the broader evidence of psychological dysfunction, evident on assessments of cognitive control (goal-driven behaviour, impulsivity), reward-driven decision-making (temporal discounting, gambling), and elevated rates of self-report negative affect (anxiety, depression, anhedonia). The implications of these findings are discussed with reference to the research domain criteria and, relatedly, directions for future research. KEY MESSAGES: The identification of markers of ICB that allow early diagnosis, monitoring, and optimisation of therapy is an ambitious goal. And whilst we have pulled together a number of convergent findings identified using different paradigms, we are still some distance off understanding the mechanism(s) that increase vulnerability to ICB. It is our hope that this review spurs future studies to further investigate the interaction between motivation and cognition with the twin aims of identifying markers of ICB that have both clinical utility and function as outcome measures in therapeutic clinical trials.
Subject(s)
Parkinson Disease , Humans , Reproducibility of Results , Compulsive Behavior/metabolism , Impulsive Behavior , Dopamine/metabolism , Dopamine/therapeutic useABSTRACT
Compulsivity is defined as an unstoppable tendency toward repetitive and habitual actions, which are reiterated despite negative consequences. Polydipsia is induced preclinically by intermittent reward, leading rodents to ingest large amounts of fluids. We focused on the role of dopamine transporter (DAT) and inheritance factors in compulsive behavior. Our sample consisted of DAT heterozygous (HET) rats with different genetic inheritance (MAT-HET, born from WT-dams × KO-fathers; MIX-HET, born from HET-dams × KO-fathers). As controls, we used both wild-type (WT) rats and their socially-isolated (WTi) siblings. We ran the schedule-induced polydipsia (SIP) protocol, to induce compulsive behavior; then the Y-maze and marble-burying tests, to verify its actual development. Only MAT-HET (who inherited the functional DAT allele from the WT mother) is vulnerable to developing compulsive behavior. MAT-HET rats drank increasingly more water during SIP; they showed significant perseverance in the Y-maze test and exhibited compulsive actions in the marble-burying test. Interestingly, compulsive behaviors of MAT-HET rats correlated with expression ex vivo of different genes in different areas. Regarding the prefrontal cortex (PFC), D2R correlated with Y-maze "perseverance" in addition to BDNF; considering the amygdala (AMY), both D3R and OXTR correlated with SIP "licks." Indeed, compulsivity may be linked to D2R and BDNF in PFC, while extreme anxiety in MAT-HET rats may be associated with D3R and OXTR in the AMY. These results confirm some similarities between MAT-HET and DAT-KO subjects, and link the epigenetic context of the DAT gene to the development of compulsive behavior.
Subject(s)
Dopamine Plasma Membrane Transport Proteins , Dopamine , Alleles , Animals , Behavior, Animal , Brain-Derived Neurotrophic Factor/metabolism , Calcium Carbonate/metabolism , Compulsive Behavior/genetics , Compulsive Behavior/metabolism , Disease Models, Animal , Dopamine Plasma Membrane Transport Proteins/genetics , Humans , Polydipsia/genetics , RatsABSTRACT
Compulsivity is a key manifestation of inhibitory control deficit and a cardinal symptom of psychopathological conditions such as obsessive-compulsive and attention-deficit hyperactivity disorders, in which metabolic alterations have raised attention as putative biomarkers for early identification. The present study assessed the metabolic profile in a preclinical model of a compulsive phenotype of rats. We used the schedule-induced polydipsia (SIP) method to classify male Wistar rats into high drinkers (HDs) or low drinkers (LDs) according to their compulsive drinking rate developed by exposure to a fixed-time 60 s (FT-60) schedule of reinforcement with water available ad libitum during 20 sessions. Before and after SIP, blood samples were collected for subsequent serum analysis by nuclear magnetic resonance spectroscopy coupled to multivariate analysis. Although no differences existed in the pre-SIP set, the compulsive drinking behavior induced remarkable metabolic alterations: HD rats selected by SIP exhibited a hyperlipidemic, hypoglycemic, and hyperglutaminergic profile compared with their low-compulsive counterparts. Interestingly, these alterations were not attributable to the mere exposure to reward pellets because a control experiment did not show differences between HDs and LDs after 20 sessions of pellet consumption without intermittent reinforcement. Our results shed light toward the implication of dietary and metabolic factors underpinning the vulnerability to compulsive behaviors.
Subject(s)
Compulsive Behavior , Fatty Acids , Animals , Biomarkers , Compulsive Behavior/metabolism , Compulsive Behavior/pathology , Disease Models, Animal , Magnetic Resonance Spectroscopy , Male , Metabolomics , Polydipsia/metabolism , Rats , Rats, WistarABSTRACT
Mild behavioral impairment (MBI), which can include compulsive behavior, is an early sign of Alzheimer's disease (AD), but its underlying neural mechanisms remain unclear. Here, we show that 3-5-month-old APP/PS1 mice display obsessive-compulsive disorder (OCD)-like behavior. The number of parvalbumin-positive (PV) interneurons and level of high gamma (γhigh) oscillation are significantly decreased in the striatum of AD mice. This is accompanied by enhanced ß-γhigh coupling and firing rates of putative striatal projection neurons (SPNs), indicating decorrelation between PV interneurons and SPNs. Local field potentials (LFPs) simultaneously recorded in prefrontal cortex (PFC) and striatum (Str) demonstrate a decrease in γhigh-band coherent activity and spike-field coherence in corticostriatal circuits of APP/PS1 mice. Furthermore, levels of GABAB receptor (GABABR), but not GABAA receptor (GABAAR), and glutamatergic receptors, were markedly reduced, in line with presymptomatic AD-related behavioral changes. These findings suggest that MBI occurs as early as 3-5 months in APP/PS1 mice and that altered corticostriatal synchronization may play a role in mediating the behavioral phenotypes observed.
Subject(s)
Alzheimer Disease/physiopathology , Compulsive Behavior/physiopathology , Corpus Striatum/physiopathology , Interneurons/physiology , Neural Pathways/physiopathology , Prefrontal Cortex/physiopathology , Alzheimer Disease/metabolism , Amyloid beta-Protein Precursor/genetics , Animals , Compulsive Behavior/metabolism , Corpus Striatum/metabolism , Disease Models, Animal , Female , Male , Mice , Mice, Transgenic , Neural Pathways/metabolism , Prefrontal Cortex/metabolism , Presenilins/genetics , Receptors, GABA-B/metabolismABSTRACT
While most individuals with access to alcohol drink it recreationally, some vulnerable individuals eventually lose control over their intake and progressively develop compulsive alcohol drinking and decreased interest in alternative sources of reinforcement, two key features of addiction. The neural and molecular mechanisms underlying this vulnerability to switch from controlled to compulsive alcohol intake have not been fully elucidated. It has been shown that rats having reduced levels of expression of the gamma-aminobutyric acid (GABA) transporter, GAT-3, in the amygdala tend to persist in seeking and drinking alcohol even when adulterated with quinine, suggesting that pharmacological interventions aimed at restoring GABA homeostasis in these individuals may provide a targeted treatment to limit compulsive alcohol drinking. Here, we tested the hypothesis that the GABAB receptor agonist baclofen, which decreases GABA release, specifically reduces compulsive alcohol drinking in vulnerable individuals. In a large cohort of Sprague-Dawley rats allowed to drink alcohol under an intermittent two-bottle choice procedure, a cluster of individuals was identified that persisted in drinking alcohol despite adulteration with quinine or when an alternative ingestive reinforcer, saccharin, was available. In these rats, which were characterized by decreased GAT-3 mRNA levels in the central amygdala, acute baclofen administration (1.5 mg/kg, intraperitoneal) resulted in a decrease in compulsive drinking. These results indicate that low GAT-3 mRNA levels in the central amygdala may represent an endophenotype of vulnerability to develop a compulsive drinking of alcohol that is shown here to be mitigated by baclofen.
Subject(s)
Alcoholism/metabolism , Baclofen/pharmacology , Polymers/metabolism , Animals , Central Amygdaloid Nucleus/drug effects , Compulsive Behavior/metabolism , Conditioning, Operant/drug effects , Ethanol/pharmacology , Male , Quinine/pharmacology , Rats , Rats, Sprague-Dawley , Reinforcement, Psychology , Self AdministrationABSTRACT
Repetitive behavior is a widely observed neuropsychiatric symptom. Abnormal dopaminergic signaling in the striatum is one of the factors associated with behavioral repetition; however, the molecular mechanisms underlying the induction of repetitive behavior remain unclear. Here, we demonstrated that the NOX1 isoform of the superoxide-producing enzyme NADPH oxidase regulated repetitive behavior in mice by facilitating excitatory synaptic inputs in the central striatum (CS). In male C57Bl/6J mice, repeated stimulation of D2 receptors induced abnormal behavioral repetition and perseverative behavior. Nox1 deficiency or acute pharmacological inhibition of NOX1 significantly shortened repeated D2 receptor stimulation-induced repetitive behavior without affecting motor responses to a single D2 receptor stimulation. Among brain regions, Nox1 showed enriched expression in the striatum, and repeated dopamine D2 receptor stimulation further increased Nox1 expression levels in the CS, but not in the dorsal striatum. Electrophysiological analyses revealed that repeated D2 receptor stimulation facilitated excitatory inputs in the CS indirect pathway medium spiny neurons (iMSNs), and this effect was suppressed by the genetic deletion or pharmacological inhibition of NOX1. Nox1 deficiency potentiated protein tyrosine phosphatase activity and attenuated the accumulation of activated Src kinase, which is required for the synaptic potentiation in CS iMSNs. Inhibition of NOX1 or ß-arrestin in the CS was sufficient to ameliorate repetitive behavior. Striatal-specific Nox1 knockdown also ameliorated repetitive and perseverative behavior. Collectively, these results indicate that NOX1 acts as an enhancer of synaptic facilitation in CS iMSNs and plays a key role in the molecular link between abnormal dopamine signaling and behavioral repetition and perseveration.SIGNIFICANCE STATEMENT Behavioral repetition is a form of compulsivity, which is one of the core symptoms of psychiatric disorders, such as obsessive-compulsive disorder. Perseveration is also a hallmark of such disorders. Both clinical and animal studies suggest important roles of abnormal dopaminergic signaling and striatal hyperactivity in compulsivity; however, the precise molecular link between them remains unclear. Here, we demonstrated the contribution of NOX1 to behavioral repetition induced by repeated stimulation of D2 receptors. Repeated stimulation of D2 receptors upregulated Nox1 mRNA in a striatal subregion-specific manner. The upregulated NOX1 promoted striatal synaptic facilitation in iMSNs by enhancing phosphorylation signaling. These results provide a novel mechanism for D2 receptor-mediated excitatory synaptic facilitation and indicate the therapeutic potential of NOX1 inhibition in compulsivity.
Subject(s)
Compulsive Behavior/metabolism , Locomotion/physiology , NADPH Oxidase 1/biosynthesis , NADPH Oxidases/biosynthesis , Receptors, Dopamine D2/biosynthesis , Synapses/metabolism , Animals , Cells, Cultured , Compulsive Behavior/chemically induced , Compulsive Behavior/psychology , Dopamine Agonists/pharmacology , Dopamine Agonists/toxicity , Locomotion/drug effects , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NADPH Oxidase 1/antagonists & inhibitors , NADPH Oxidases/antagonists & inhibitors , Pyrazolones/pharmacology , Pyridones/pharmacology , Receptors, Dopamine D2/agonists , Synapses/drug effectsABSTRACT
The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose.
Subject(s)
Compulsive Behavior/physiopathology , Disruptive, Impulse Control, and Conduct Disorders/physiopathology , Impulsive Behavior/physiology , Parkinson Disease/physiopathology , Antidepressive Agents , Cohort Studies , Comorbidity , Compulsive Behavior/drug therapy , Compulsive Behavior/metabolism , Cross-Sectional Studies , Disruptive, Impulse Control, and Conduct Disorders/drug therapy , Disruptive, Impulse Control, and Conduct Disorders/metabolism , Dopamine/metabolism , Dopamine Agonists/therapeutic use , Female , Follow-Up Studies , Humans , Impulsive Behavior/drug effects , Male , Middle Aged , Parkinson Disease/drug therapy , Parkinson Disease/metabolism , Quality of Life , Risk Factors , Spain , Surveys and QuestionnairesABSTRACT
RATIONALE: Checking is a functional behaviour that provides information to guide behaviour. However, in obsessive-compulsive disorder (OCD), checking may escalate to dysfunctional levels. The processes underpinning the transition from functional to dysfunctional checking are unclear but may be associated with individual differences that support the development of maladaptive behaviour. We examined one such predisposition, sign-tracking to a pavlovian conditioned stimulus, which we previously found associated with dysfunctional checking. How sign-tracking interacts with another treatment with emerging translational validity for OCD-like checking, chronic administration of the dopamine D2 receptor agonist quinpirole, is unknown. OBJECTIVES: We tested how functional and dysfunctional checking in the rat observing response task (ORT) was affected by chronic quinpirole administration in non-autoshaped controls and autoshaped animals classified as sign-trackers or goal-trackers. METHODS: Sign-trackers or goal-trackers were trained on the ORT before the effects of chronic quinpirole administration on checking were assessed. Subsequently, the effects on checking of different behavioural challenges, including reward omission and the use of unpredictable reinforcement schedules, were tested. RESULTS: Prior autoshaping increased checking. Sign-trackers and goal-trackers responded differently to quinpirole sensitization, reward omission and reinforcement uncertainty. Sign-trackers showed greater elevations in dysfunctional checking, particularly during uncertainty. By contrast, goal-trackers predominantly increased functional checking responses, possibly in response to reduced discrimination accuracy in the absence of cues signalling which lever was currently active. CONCLUSIONS: The results are discussed in terms of how pavlovian associations influence behaviour that becomes compulsive in OCD and how this may be dependent on striatal dopamine D2 receptors.
Subject(s)
Behavior, Animal/drug effects , Compulsive Behavior/psychology , Dopamine Agonists/pharmacology , Goals , Obsessive-Compulsive Disorder/psychology , Quinpirole/pharmacology , Animals , Compulsive Behavior/metabolism , Conditioning, Classical/drug effects , Conditioning, Operant , Cues , Dopamine/metabolism , Male , Motivation/drug effects , Obsessive-Compulsive Disorder/metabolism , Rats , Reinforcement Schedule , Reinforcement, Psychology , RewardABSTRACT
Fronto-limbic structures and serotonin 2A receptors (5-HT2A) have been implicated in the pathophysiology and treatment of compulsive spectrum disorders. Schedule-Induced Polydipsia (SIP), characterized by the development of excessive drinking under intermittent food reinforcement schedules, is a valid preclinical model for studying the compulsive phenotype. In the present study, we explored the individual differences and effect of SIP in brain volume and 5-HT2A receptor binding in fronto-limbic structures in rats selected according to their compulsive drinking behavior. Rats were divided into high (HD) and low drinkers (LD) by SIP (20 sessions); later, we analyzed the brains of HD and LD selected rats, in two different conditions: non-re-exposure (NRE) or re-exposure to SIP (RE), with four groups: LD-NRE, LD-RE, HD-NRE and HD-RE. Histological analyses were carried out for volumetric (stereology) and receptor binding (autoradiography) in the prelimbic and infralimbic cortex, dorsal hippocampus and basolateral amygdala. After SIP re-exposure, HD-RE showed an increased basolateral amygdala and a reduced hippocampus volume compared to HD-NRE rats, and also compared to LD-RE rats. No differences were found between HD and LD in NRE condition. Moreover, HD rats exhibit a lower 5-HT2A receptor binding in the basolateral amygdala, independently of SIP re-exposure, compared to LD rats. However, LD-RE showed a decreased 5-HT2A receptor binding in basolateral amygdala compared to LD-NRE. No differences were found in the remaining structures. These findings suggest that SIP might be differentially impacting HD and LD brains, pointing towards a possible explanation of how the latent vulnerability to compulsivity is triggered.
Subject(s)
Basolateral Nuclear Complex , Compulsive Behavior , Drinking Behavior/physiology , Gyrus Cinguli , Hippocampus , Polydipsia , Prefrontal Cortex , Receptor, Serotonin, 5-HT2A/metabolism , Animals , Basolateral Nuclear Complex/metabolism , Basolateral Nuclear Complex/pathology , Behavior, Animal/physiology , Compulsive Behavior/metabolism , Compulsive Behavior/pathology , Compulsive Behavior/physiopathology , Disease Models, Animal , Gyrus Cinguli/metabolism , Gyrus Cinguli/pathology , Hippocampus/metabolism , Hippocampus/pathology , Hippocampus/physiopathology , Male , Polydipsia/etiology , Polydipsia/metabolism , Polydipsia/pathology , Polydipsia/physiopathology , Prefrontal Cortex/metabolism , Prefrontal Cortex/pathology , Rats , Rats, Wistar , Reinforcement ScheduleABSTRACT
RATIONALE: Obsessive-compulsive disorder (OCD) is characterized by repetitive behaviors exacerbated by stress. Many OCD patients do not respond to available pharmacotherapies, but neurosurgical ablation of the anterior cingulate cortex (ACC) can provide symptomatic relief. Although the ACC receives noradrenergic innervation and expresses adrenergic receptors (ARs), the involvement of norepinephrine (NE) in OCD has not been investigated. OBJECTIVE: To determine the effects of genetic or pharmacological disruption of NE neurotransmission on marble burying (MB) and nestlet shredding (NS), two animal models of OCD. METHODS: We assessed NE-deficient (Dbh -/-) mice and NE-competent (Dbh +/-) controls in MB and NS tasks. We also measured the effects of anti-adrenergic drugs on NS and MB in control mice and the effects of pharmacological restoration of central NE in Dbh -/- mice. Finally, we compared c-fos induction in the locus coeruleus (LC) and ACC of Dbh -/- and control mice following both tasks. RESULTS: Dbh -/- mice virtually lacked MB and NS behaviors seen in control mice but did not differ in the elevated zero maze (EZM) model of general anxiety-like behavior. Pharmacological restoration of central NE synthesis in Dbh -/- mice completely rescued NS behavior, while NS and MB were suppressed in control mice by anti-adrenergic drugs. Expression of c-fos in the ACC was attenuated in Dbh -/- mice after MB and NS. CONCLUSION: These findings support a role for NE transmission to the ACC in the expression of stress-induced compulsive behaviors and suggest further evaluation of anti-adrenergic drugs for OCD is warranted.
Subject(s)
Compulsive Behavior/metabolism , Disease Models, Animal , Norepinephrine/metabolism , Obsessive-Compulsive Disorder/metabolism , Stress, Psychological/metabolism , Adrenergic alpha-1 Receptor Antagonists/pharmacology , Adrenergic alpha-1 Receptor Antagonists/therapeutic use , Animals , Compulsive Behavior/drug therapy , Compulsive Behavior/psychology , Female , Male , Mice , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Norepinephrine/antagonists & inhibitors , Obsessive-Compulsive Disorder/drug therapy , Obsessive-Compulsive Disorder/psychology , Receptors, Adrenergic/metabolism , Rodentia , Stress, Psychological/drug therapy , Stress, Psychological/psychologyABSTRACT
Alcohol use disorder (AUD) is a chronic, relapsing disorder that is characterized by the compulsive use of alcohol despite numerous health, social, and economic consequences. Initially, the use of alcohol is driven by positive reinforcement. Over time, however, alcohol use can take on a compulsive quality that is driven by the desire to avoid the negative consequences of abstinence, including negative affect and heightened stress/anxiety. This transition from positive reinforcement- to negative reinforcement-driven consumption involves the corticotropin-releasing factor (CRF) system, although mounting evidence now suggests that the CRF system interacts with other neural systems to ultimately produce behaviors that are symptomatic of compulsive alcohol use, such as the hypocretin (Hcrt) system. Hypocretins are produced exclusively in the hypothalamus, but Hcrt neurons project widely throughout the brain and reach regions that perform regulatory functions for numerous behavioral and physiological responses-including the infralimbic cortex (IL) of the medial prefrontal cortex (mPFC). Although the entire mPFC undergoes neuroadaptive changes following prolonged alcohol exposure, the IL appears to undergo more robust changes compared with other mPFC substructures. Evidence to date suggests that the IL is likely involved in EtOH-seeking behavior, but ambiguities with respect to the specific role of the IL in this regard make it difficult to draw definitive conclusions. Furthermore, the manner in which CRF interacts with Hcrt in this region as it pertains to alcohol-seeking behavior is largely unknown, although immunohistochemical and electrophysiological experiments have shown that CRF and Hcrt directly interact in the mPFC, suggesting that the interaction between CRF and Hcrt in the IL may be critically important for the development and subsequent maintenance of compulsive alcohol seeking. This review aims to consolidate recent literature regarding the role of the IL in alcohol-seeking behavior and to discuss evidence that supports a functional interaction between Hcrt and CRF in the IL.
Subject(s)
Alcoholism/metabolism , Compulsive Behavior/metabolism , Corticotropin-Releasing Hormone/metabolism , Drug-Seeking Behavior/physiology , Orexins/metabolism , Prefrontal Cortex/metabolism , Alcoholism/drug therapy , Animals , Benzoxazoles/metabolism , Benzoxazoles/pharmacology , Benzoxazoles/therapeutic use , Compulsive Behavior/drug therapy , Drug-Seeking Behavior/drug effects , Humans , Naphthyridines/metabolism , Naphthyridines/pharmacology , Naphthyridines/therapeutic use , Prefrontal Cortex/drug effects , Protein Binding/physiology , Urea/analogs & derivatives , Urea/metabolism , Urea/pharmacology , Urea/therapeutic useABSTRACT
Family, adoption and twin studies have highlighted the significant role of heritable influences on individual differences in opioid addiction. Meanwhile, obsessive-compulsive disorder (OCD) is a disorder wherein the individual experiences recurring thoughts that cause irrational fears and anxiety. In the present study, adult male and female rats received morphine solution for 21 days and were drug-free for 10 days. Offspring were used in 4 distinct groups; (1) paternal morphine-exposed, (2) maternal morphine-exposed, (3) maternal and paternal morphine-exposed, and (4) drug-naïve subjects. We assessed the grooming behavior and marble burying test as an indicator of obsessive-compulsive behavior. To clarify the mechanisms underlying these changes, the mRNA level of BDNF, the phosphorylation level of CREB and the protein level of D2 dopamine receptor (DR) were evaluated in the nucleus accumbens (NAc). The grooming behavior in male offspring with one or two morphine-abstinent parent(s) increased compared with the offspring of drug naïve rats. In addition, the offspring of morphine-exposed parents buried more marbles when compared with the offspring of drug-naïve parents. Also, the BDNF mRNA was down-regulated in the NAC. However, the levels of phospho-CREB and D2 DR were elevated. Previous studies indicated that exposure to morphine in adulthood enhances the risk of psychiatric disorders in offspring. OCD is one the comorbid disorders with addiction and increases the risk of substance abuse disorder in patients. In this survey, we found that morphine exposure in parents before gestation can encourage obsessive-compulsive behavior in offspring.
Subject(s)
Analgesics, Opioid/adverse effects , Behavior, Animal/drug effects , Compulsive Behavior/chemically induced , Morphine/adverse effects , Obsessive-Compulsive Disorder/chemically induced , Prenatal Exposure Delayed Effects , Animals , Brain-Derived Neurotrophic Factor/genetics , Compulsive Behavior/metabolism , Disease Models, Animal , Female , Grooming/drug effects , Male , Maternal-Fetal Exchange , Nucleus Accumbens/drug effects , Nucleus Accumbens/metabolism , Obsessive-Compulsive Disorder/metabolism , Pregnancy , Rats, Wistar , Receptors, Dopamine D2/metabolismABSTRACT
Impulsive compulsive behaviours in Parkinson's disease have been linked to increased dopaminergic release in the ventral striatum and excessive stimulation of dopamine D3 receptors. Thirty-one patients with impulsive compulsive behaviours and Parkinson's disease who donated their brains to the Queen Square Brain Bank for Neurological Disorders were assessed for α-synuclein neuropathological load and tyrosine hydroxylase levels in the nucleus accumbens, dorsal putamen and caudate using immunohistochemistry. Dopamine D2 and dopamine D3 receptors protein levels in the nucleus accumbens, frontal cortex and putamen were determined using western blotting. Results were compared to 29 Parkinson's disease cases without impulsive compulsive behaviours matched by age, sex, disease duration, age at Parkinson's disease onset and disease duration. The majority of patients with impulsive compulsive behaviours had dopamine dysregulation syndrome. Patients with Parkinson's disease and impulsive compulsive behaviours had lower α-synuclein load and dopamine D3 receptor levels in the nucleus accumbens. No differences were seen between groups in the other brain areas and in the analysis of tyrosine hydroxylase and dopamine D2 receptor levels. Lower α-synuclein load in the nucleus accumbens of individuals with Parkinson's disease and impulsive compulsive behaviours was confirmed on western blotting. Downregulation of the dopamine D3 receptor levels may have occurred either as a consequence of the degenerative process or of a pre-morbid trait. The lower levels of α-synuclein may have contributed to an excessive stimulation of the ventral striatum resulting in impulsive compulsive behaviours.
Subject(s)
Compulsive Behavior/metabolism , Compulsive Behavior/psychology , Impulsive Behavior , Nucleus Accumbens/metabolism , Parkinson Disease/metabolism , Parkinson Disease/psychology , Receptors, Tumor Necrosis Factor, Member 25/metabolism , alpha-Synuclein/metabolism , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Autopsy , Compulsive Behavior/pathology , Female , Humans , Lewy Body Disease/metabolism , Lewy Body Disease/pathology , Male , Middle Aged , Nucleus Accumbens/pathology , Parkinson Disease/pathology , Receptors, Dopamine D2/metabolism , Tyrosine 3-Monooxygenase/metabolismABSTRACT
BTB/POZ domain-containing 3 (BTBD3) was identified as a potential risk gene in the first genome-wide association study of obsessive-compulsive disorder (OCD). BTBD3 is a putative transcription factor implicated in dendritic pruning in developing primary sensory cortices. We assessed whether BTBD3 also regulates neural circuit formation within limbic cortico-striato-thalamo-cortical circuits and behaviors related to OCD in mice. Behavioral phenotypes associated with OCD that are measurable in animals include compulsive-like behaviors and reduced exploration. We tested Btbd3 wild-type, heterozygous, and knockout mice for compulsive-like behaviors including cage-mate barbering, excessive wheel-running, repetitive locomotor patterns, and reduced goal-directed behavior in the probabilistic learning task (PLT), and for exploratory behavior in the open field, digging, and marble-burying tests. Btbd3 heterozygous and knockout mice showed excessive barbering, wheel-running, impaired goal-directed behavior in the PLT, and reduced exploration. Further, chronic treatment with fluoxetine, but not desipramine, reduced barbering in Btbd3 wild-type and heterozygous, but not knockout mice. In contrast, Btbd3 expression did not alter anxiety-like, depression-like, or sensorimotor behaviors. We also quantified dendritic morphology within anterior cingulate cortex, mediodorsal thalamus, and hippocampus, regions of high Btbd3 expression. Surprisingly, Btbd3 knockout mice only showed modest increases in spine density in the anterior cingulate, while dendritic morphology was unaltered elsewhere. Finally, we virally knocked down Btbd3 expression in whole, or just dorsal, hippocampus during neonatal development and assessed behavior during adulthood. Whole, but not dorsal, hippocampal Btbd3 knockdown recapitulated Btbd3 knockout phenotypes. Our findings reveal that hippocampal Btbd3 expression selectively modulates compulsive-like and exploratory behavior.
Subject(s)
Brain/metabolism , Compulsive Behavior/metabolism , Exploratory Behavior/physiology , Nerve Net/metabolism , Nerve Tissue Proteins/metabolism , Animals , Antidepressive Agents/pharmacology , Antidepressive Agents/therapeutic use , Behavior, Animal/drug effects , Behavior, Animal/physiology , Compulsive Behavior/drug therapy , Compulsive Behavior/genetics , Desipramine/pharmacology , Desipramine/therapeutic use , Disease Models, Animal , Exploratory Behavior/drug effects , Fluoxetine/pharmacology , Fluoxetine/therapeutic use , Mice , Mice, Knockout , Motor Activity/drug effects , Motor Activity/physiology , Nerve Tissue Proteins/genetics , Obsessive-Compulsive Disorder/genetics , Obsessive-Compulsive Disorder/metabolismABSTRACT
Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder with childhood onset, and is characterized by intrusive thoughts and fears (obsessions) that lead to repetitive behaviors (compulsions). Previously, we identified insulin signaling being associated with OCD and here, we aim to further investigate this link in vivo. We studied TALLYHO/JngJ (TH) mice, a model of type 2 diabetes mellitus, to (1) assess compulsive and anxious behaviors, (2) determine neuro-metabolite levels by 1 H magnetic resonance spectroscopy (MRS) and brain structural connectivity by diffusion tensor imaging (DTI), and (3) investigate plasma and brain protein levels for molecules previously associated with OCD (insulin, Igf1, Kcnq1, and Bdnf) in these subjects. TH mice showed increased compulsivity-like behavior (reduced spontaneous alternation in the Y-maze) and more anxiety (less time spent in the open arms of the elevated plus maze). In parallel, their brains differed in the white matter microstructure measures fractional anisotropy (FA) and mean diffusivity (MD) in the midline corpus callosum (increased FA and decreased MD), in myelinated fibers of the dorsomedial striatum (decreased FA and MD), and superior cerebellar peduncles (decreased FA and MD). MRS revealed increased glucose levels in the dorsomedial striatum and increased glutathione levels in the anterior cingulate cortex in the TH mice relative to their controls. Igf1 expression was reduced in the cerebellum of TH mice but increased in the plasma. In conclusion, our data indicates a role of (abnormal) insulin signaling in compulsivity-like behavior.
Subject(s)
Brain/metabolism , Compulsive Behavior/metabolism , Insulin/metabolism , Signal Transduction/physiology , Animals , Anxiety/diagnostic imaging , Anxiety/metabolism , Blood Glucose , Brain/diagnostic imaging , Brain-Derived Neurotrophic Factor/metabolism , Compulsive Behavior/diagnostic imaging , Diabetes Mellitus, Type 2/diagnostic imaging , Diabetes Mellitus, Type 2/metabolism , Diffusion Tensor Imaging , Disease Models, Animal , Insulin-Like Growth Factor I/metabolism , KCNQ1 Potassium Channel/metabolism , Magnetic Resonance Spectroscopy , Mice , Proteomics , White Matter/diagnostic imagingABSTRACT
Mental health disorders are manifested in families, yet cannot be fully explained by classical Mendelian genetics. Changes in gene expression via epigenetics present a plausible mechanism. Anxiety often leads to avoidant behaviors which upon repetition may become habitual, maladaptive and resistant to extinction as observed in obsessive compulsive disorders (OCD). Psychophysical models of OCD propose that anxiety (amygdala) and habits (dorsolateral striatum, DLS) may be causally linked. The amygdala activates spiny projection neurons in the DLS. Repetitive amygdala terminal stimulation in the DLS elicits long term OCD-like behavior in mice associated with circuitry changes and gene methylation-mediated decrease in the activity of protein phosphatase 1 (PP1). Treatment of OCD-like grooming behavior in Slitrk5, SAPAP3, and laser-stimulated mice with one dose of RG108 (DNA methyltransferase inhibitor), lead to marked symptom improvement lasting for at least one week as well as complete reversal of anomalous changes in circuitry and PP1 gene methylation.
Subject(s)
Compulsive Behavior , DNA Methylation/drug effects , Epigenesis, Genetic/drug effects , Obsessive-Compulsive Disorder , Phthalimides/pharmacology , Tryptophan/analogs & derivatives , Animals , Compulsive Behavior/drug therapy , Compulsive Behavior/genetics , Compulsive Behavior/metabolism , Compulsive Behavior/pathology , Disease Models, Animal , Female , Humans , Male , Mice , Obsessive-Compulsive Disorder/drug therapy , Obsessive-Compulsive Disorder/genetics , Obsessive-Compulsive Disorder/metabolism , Obsessive-Compulsive Disorder/pathology , Tryptophan/pharmacologyABSTRACT
The acquisition of drug, including alcohol, use is associated with activation of the mesolimbic dopamine system. However, over the course of drug exposure the control over drug seeking progressively devolves to anterior dorsal striatum (aDLS) dopamine-dependent mechanisms. The causal importance of this functional recruitment of aDLS in the switch from controlled to compulsive drug use in vulnerable individuals remains to be established. Here we tested the hypothesis that individual differences in the susceptibility to aDLS dopamine-dependent control over alcohol seeking predicts and underlies the development of compulsive alcohol seeking. Male alcohol-preferring rats, the alcohol-preferring phenotype of which was confirmed in an intermittent two-bottle choice procedure, were implanted bilaterally with cannulae above the aDLS and trained instrumentally on a seeking-taking chained schedule of alcohol reinforcement until some individuals developed compulsive seeking behavior. The susceptibility to aDLS dopamine control over behavior was investigated before and after the development of compulsivity by measuring the extent to which bilateral aDLS infusions of the dopamine receptor antagonist α-flupenthixol (0, 5, 10, and 15 µg/side) decreased alcohol seeking at different stages of training, as follows: (1) after acquisition of instrumental taking responses for alcohol; (2) after alcohol-seeking behavior was well established; and (3) after the development of punishment-resistant alcohol seeking. Only alcohol-seeking, not alcohol-taking, responses became dependent on aDLS dopamine. Further, marked individual differences in the susceptibility of alcohol seeking to aDLS dopamine receptor blockade actually predicted the vulnerability to develop compulsive alcohol seeking, but only in subjects dependent on aDLS dopamine-dependent control.SIGNIFICANCE STATEMENT Over the course of addictive drug exposure, there is a transition in the control over drug seeking from ventral to anterior dorsal striatum (aDLS) dopamine-dependent mechanisms, but it is unclear whether this is causally involved in the development of compulsive drug seeking. We tested the hypothesis that individual differences in the reliance of alcohol seeking on aDLS dopamine predicts and underlies the emergence of compulsive alcohol seeking. We identified individual differences in the reliance of well established alcohol seeking, but not taking behavior, on aDLS mechanisms and also showed that this predicted the subsequent development of compulsive alcohol-seeking behavior. Thus, those individuals in whom alcohol seeking depended on aDLS mechanisms were vulnerable subsequently to display compulsivity.
Subject(s)
Alcoholism/physiopathology , Compulsive Behavior/physiopathology , Corpus Striatum/physiopathology , Drug-Seeking Behavior , Alcoholism/metabolism , Animals , Compulsive Behavior/metabolism , Corpus Striatum/drug effects , Dopamine/metabolism , Dopamine Antagonists/pharmacology , Flupenthixol/pharmacology , Male , Rats , RewardABSTRACT
Dopamine (DA) is a key neurotransmitter of the central nervous system, whose availability is regulated by the dopamine transporter (DAT). Deletion of DAT gene leading to hyperdopaminergia was previously performed on mouse models. This enabled recapitulation of the core symptoms of Attention-Deficit / Hyper-activity Disorder (ADHD), which include hyperactivity, inattention and cognitive impairment. We used recently developed DAT knockout (DAT-KO) rats to carry out further behavioral profiling on this novel model of hyperdopaminergia. DAT-KO rats display elevated locomotor activity and restless environmental exploration, associated with a transient anxiety profile. Furthermore, these rats show pronounced stereotypy and compulsive-like behavior at the Marble-Burying test. Homozygous DAT-KO rats mantain intact social interaction when tested in a social-preference task, while heterozygous (HET) rats show high inactivity associated with close proximity to the social stimulus. Ex-vivo evaluation of brain catecholamines highlighted increased levels of norepinephrine in the hippocampus and hypothalamus exclusively of heterozygous rats. Taken together, our data present evidence of unexpected asocial tendencies in heterozygous (DAT-HET) rats associated with neurochemical alterations in norepinephrine neurotransmission. We shed light on the behavioral and neurochemical consequences of altered DAT function in a higher, more complex model of hyperdopaminergia. Unraveling the role of DA neurotransmission in DAT-KO rats has very important implications in the understanding of many psychiatric illnesses, including ADHD, where alterations in DA system have been demonstrated.
Subject(s)
Brain/metabolism , Dopamine Plasma Membrane Transport Proteins/deficiency , Norepinephrine/metabolism , Social Behavior , Animals , Attention Deficit Disorder with Hyperactivity/metabolism , Attention Deficit Disorder with Hyperactivity/psychology , Compulsive Behavior/metabolism , Conditioning, Psychological/physiology , Disease Models, Animal , Dopamine Plasma Membrane Transport Proteins/genetics , Exploratory Behavior/physiology , Fear/physiology , Grooming/physiology , Heterozygote , Homozygote , Motor Activity/physiology , Phenotype , Rats, Transgenic , Rats, WistarABSTRACT
Addiction is now recognized as a neurobiological and cognitive brain disorder and is generally viewed as a switch from recreational or voluntary to compulsive substance use despite aversive consequences. The habenula, composed of medial (MHb) and lateral (LHb) domains, has been implicated in regulating behavioral flexibility and anxiety-related behaviors and is considered a core component of the brain "anti-reward" system. These functions position the habenula to influence voluntary behaviors. Consistent with this view, emerging evidence points to alterations in habenula activity as important factors to contributing the loss of control over the use of drugs of abuse and the emergence of compulsive drug seeking behaviors. In this review, we will discuss the general functions of the MHb and LHb and describe how these functional properties allow this brain region to promote or suppress volitional behaviors. Then, we highlight mechanisms by which drugs of abuse may alter habenular activity, precipitating the emergence of addiction-relevant behavioral abnormalities.
Subject(s)
Avoidance Learning , Compulsive Behavior , Habenula , Motivation , Reward , Self-Control , Substance-Related Disorders , Animals , Avoidance Learning/physiology , Compulsive Behavior/metabolism , Compulsive Behavior/physiopathology , Habenula/metabolism , Habenula/physiopathology , Humans , Motivation/physiology , Substance-Related Disorders/metabolism , Substance-Related Disorders/physiopathologyABSTRACT
Impulsive-compulsive spectrum disorders are associated with dopamine agonist therapy in some patients. These untoward outcomes occur with direct-acting, full and partial agonists at D2 dopamine family receptors. The disorders typically emerge during chronic treatment, and exhibit common features that are independent of the neurological or psychiatric pathology for which the initial therapy was indicated. It is well-documented that the brain is 'plastic', changing in response to alterations to internal factors (e.g., disease processes), as well as external factors (e.g., therapies). The complexities of these clinical scenarios have eluded a clear depiction of the neurobiology for impulsive-compulsive spectrum disorders and engendered considerable debate regarding the mechanistic underpinnings of the disorders. In this opinion, we use pharmacological concepts related to homeostatic compensation subsequent to chronic receptor activation to provide a unifying construct. This construct helps explain the occurrence of impulsive-compulsive spectrum disorders across disease states, and during therapy with full and partial agonists.