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Journal of Neurochemistry Mar 2024The striatum can be divided into four anatomically and functionally distinct domains: the dorsolateral, dorsomedial, ventral and the more recently identified...
The striatum can be divided into four anatomically and functionally distinct domains: the dorsolateral, dorsomedial, ventral and the more recently identified caudolateral (tail) striatum. Dopamine transmission in these striatal domains underlies many important behaviours, yet little is known about this phenomenon in the tail striatum. Furthermore, the tail is divided anatomically into four divisions (dorsal, medial, intermediate and lateral) based on the profile of D and D dopamine receptor-expressing medium spiny neurons, something that is not seen elsewhere in the striatum. Considering this organisation, how dopamine transmission occurs in the tail striatum is of great interest. We recorded evoked dopamine release in the four tail divisions, with comparison to the dorsolateral striatum, using fast-scan cyclic voltammetry in rat brain slices. Contributions of clearance mechanisms were investigated using dopamine transporter knockout (DAT-KO) rats, pharmacological transporter inhibitors and dextran. Evoked dopamine release in all tail divisions was smaller in amplitude than in the dorsolateral striatum and, importantly, regional variation was observed: dorsolateral ≈ lateral > medial > dorsal ≈ intermediate. Release amplitudes in the lateral division were 300% of that in the intermediate division, which also exhibited uniquely slow peak dopamine clearance velocity. Dopamine clearance in the intermediate division was most dependent on DAT, and no alternative dopamine transporters investigated (organic cation transporter-3, norepinephrine transporter and serotonin transporter) contributed significantly to dopamine clearance in any tail division. Our findings confirm that the tail striatum is not only a distinct dopamine domain but also that each tail division has unique dopamine transmission characteristics. This supports that the divisions are not only anatomically but also functionally distinct. How this segregation relates to the overall function of the tail striatum, particularly the processing of multisensory information, is yet to be determined.
Topics: Rats; Animals; Dopamine; Tail; Corpus Striatum; Neostriatum; Dopamine Antagonists
PubMed: 38308566
DOI: 10.1111/jnc.16052 -
Scientific Reports Aug 2022Dopamine has been implicated in the reinforcing effects of smoking. However, there remains a need for a better understanding of the effects of dopamine D1-like receptor...
Dopamine has been implicated in the reinforcing effects of smoking. However, there remains a need for a better understanding of the effects of dopamine D1-like receptor agonists on nicotine intake and the role of sex differences in the effects of dopaminergic drugs on behavior. This work studied the effects of D1-like receptor stimulation and blockade on operant responding for nicotine and food and locomotor activity in male and female rats. The effects of the D1-like receptor antagonist SCH 23390 (0.003, 0.01, 0.03 mg/kg) and the D1-like receptor agonist A77636 (0.1, 0.3, 1 mg/kg) on responding for nicotine and food, and locomotor activity were investigated. The effects of SCH 23390 were investigated 15 min and 24 h after treatment, and the effects of the long-acting drug A77636 were investigated 15 min, 24 h, and 48 h after treatment. Operant responding for nicotine and food and locomotor activity were decreased immediately after treatment with SCH 23390. Treatment with SCH 23390 did not have any long-term effects. Operant responding for nicotine was still decreased 48 h after treatment with A77636, and food responding was decreased up to 24 h after treatment. Treatment with A77636 only decreased locomotor activity at the 48 h time point. There were no sex differences in the effects of SCH 23390 or A77636. In conclusion, the D1-like receptor antagonist SCH 23390 reduces nicotine intake and causes sedation in rats. Stimulation of D1-like receptors with A77636 decreases nicotine intake at time points that the drug does not cause sedation.
Topics: Animals; Benzazepines; Conditioning, Operant; Dopamine; Dopamine Agonists; Dopamine Antagonists; Dose-Response Relationship, Drug; Female; Male; Nicotine; Rats; Receptors, Dopamine D1; Smoking
PubMed: 35986048
DOI: 10.1038/s41598-022-18081-3 -
Neuroscience May 2023Although the mechanisms underlying dystonia are largely unknown, dystonia is often associated with abnormal dopamine neurotransmission. DOPA-responsive dystonia (DRD) is...
Although the mechanisms underlying dystonia are largely unknown, dystonia is often associated with abnormal dopamine neurotransmission. DOPA-responsive dystonia (DRD) is a prototype disorder for understanding dopamine dysfunction in dystonia because it is caused by mutations in genes necessary for the synthesis of dopamine and alleviated by the indirect-acting dopamine agonist l-DOPA. Although adaptations in striatal dopamine receptor-mediated intracellular signaling have been studied extensively in models of Parkinson's disease, another movement disorders associated with dopamine deficiency, little is known about dopaminergic adaptations in dystonia. To identify the dopamine receptor-mediated intracellular signaling associated with dystonia, we used immunohistochemistry to quantify striatal protein kinase A activity and extracellular signal-related kinase (ERK) phosphorylation after dopaminergic challenges in a knockin mouse model of DRD. l-DOPA treatment induced the phosphorylation of both protein kinase A substrates and ERK largely in D1 dopamine receptor-expressing striatal neurons. As expected, this response was blocked by pretreatment with the D1 dopamine receptor antagonist SCH23390. The D2 dopamine receptor antagonist raclopride also significantly reduced the phosphorylation of ERK; this contrasts with models of parkinsonism in which l-DOPA-induced ERK phosphorylation is not mediated by D2 dopamine receptors. Further, the dysregulated signaling was dependent on striatal subdomains whereby ERK phosphorylation was largely confined to dorsomedial (associative) striatum while the dorsolateral (sensorimotor) striatum was unresponsive. This complex interaction between striatal functional domains and dysregulated dopamine-receptor mediated responses has not been observed in other models of dopamine deficiency, such as parkinsonism, suggesting that regional variation in dopamine-mediated neurotransmission may be a hallmark of dystonia.
Topics: Mice; Animals; Dopamine; Levodopa; Dystonia; Corpus Striatum; Parkinsonian Disorders; Dopamine Antagonists; Extracellular Signal-Regulated MAP Kinases; Receptors, Dopamine D1
PubMed: 36871883
DOI: 10.1016/j.neuroscience.2023.02.020 -
Expert Opinion on Pharmacotherapy Apr 2017Drug development and repurposing are urgently needed for individuals with autism spectrum disorders (ASD) and psychiatric comorbidity, which often presents as aggression... (Review)
Review
Drug development and repurposing are urgently needed for individuals with autism spectrum disorders (ASD) and psychiatric comorbidity, which often presents as aggression and self-injury. Areas covered: We review dopamine antagonists, including classical and atypical, as well as unconventional antipsychotics in ASD. The older antipsychotic loxapine is discussed in terms of preliminary albeit limited evidence in ASD. Emerging promise of amitriptyline in ASD is discussed, together with promising BDNF effects of loxapine and amitriptyline. Expert opinion: In ASD, pharmacotherapy and specifically dopamine antagonist drugs are often prescribed for challenging behaviors including aggression. The novel antipsychotics risperidone and aripiprazole have received most study in ASD and are FDA-approved for irritability in children with ASD over age 5 years; individuals with ASD are prone to weight gain, Type II diabetes and associated side effects. Low dose loxapine has properties of classical and novel antipsychotics but importantly appears more weight neutral, and with promising use in adolescents and adults with ASD. Amitriptyline appears effective in ASD for irritability, aggression, gastrointestinal problems, and insomnia, in children, adolescents and adults however our adult data on amitriptyline in ASD is still in preparation for publication. Both loxapine and amitriptyline may stimulate BDNF; further studies are warranted.
Topics: Adolescent; Adult; Amitriptyline; Antipsychotic Agents; Aripiprazole; Autism Spectrum Disorder; Brain-Derived Neurotrophic Factor; Child; Dopamine Antagonists; Humans; Irritable Mood; Loxapine; Risperidone
PubMed: 28335658
DOI: 10.1080/14656566.2017.1308483 -
The Breast Journal 2016Granulomatous mastitis (GM) is a relatively uncommon inflammatory breast lesion with multiple suggested etiologies. Although most GM cases show association with... (Review)
Review
Granulomatous mastitis (GM) is a relatively uncommon inflammatory breast lesion with multiple suggested etiologies. Although most GM cases show association with lactation and pregnancy, a minority of cases have been linked to hyperprolactinemia caused by either dopamine antagonist medications or with intracranial lesions, such as pituitary adenoma. The goal of this study is to review the GM cases reported in the literature with a specific emphasis on those cases associated with hyperprolactinemia and prolactinomas and to identify cases of GM seen at the Cleveland Clinic Florida which demonstrate co-occurrences of GM and intracranial lesions. CoPath and Epic data bases at Cleveland Clinic Florida were searched for cases describing inflammatory breast lesions in patients with pituitary pathology. Chart reviews were conducted and pertinent medical history was extracted for case reports. H&E-stained paraffin-embedded sections retrieved from Cleveland Clinic Florida pathology storage were evaluated by light microscopy. Four cases showing a co-occurrence of GM and hyperprolactinemia were consequently identified. A prolactin-secreting pituitary adenoma was present in two of the three GM cases. The third case demonstrated a concomitant craniopharyngioma, which was also associated with a rise in serum prolactin. This phenomenon was presumably attributable to compression, resulting in compromised transport of dopamine to the adenohypophysis and subsequent disinhibition of prolactin secretion by lactotrophs. The fourth patient with GM had a similar history of elevated prolactin. Classical histopathological features of GM were found in all four cases, including noncaseating granulomas, multinucleated giant cells, epithelioid histiocytes, and chronic inflammation. Intriguingly, complete resolution of inflammatory breast lesions along with normalization of prolactin levels occurred following the surgical excision of the craniopharyngioma, suggesting that intracranial lesion-induced hyperprolactinemia might be directly causal in GM. Therefore, the authors would suggest screening for pituitary tumors and evaluate prolactin levels in the workup of GM patients without a recent history of lactation and pregnancy and no other identified etiology.
Topics: Adenoma; Adult; Bromocriptine; Dopamine Antagonists; Female; Granulomatous Mastitis; Humans; Hyperprolactinemia; Pituitary Neoplasms; Ultrasonography, Mammary
PubMed: 26705962
DOI: 10.1111/tbj.12552 -
Journal of the National Cancer Institute Aug 2021Glioblastoma is the deadliest brain tumor in adults, and the standard of care consists of surgery followed by radiation and treatment with temozolomide. Overall survival...
BACKGROUND
Glioblastoma is the deadliest brain tumor in adults, and the standard of care consists of surgery followed by radiation and treatment with temozolomide. Overall survival times for patients suffering from glioblastoma are unacceptably low indicating an unmet need for novel treatment options.
METHODS
Using patient-derived HK-157, HK-308, HK-374, and HK-382 glioblastoma lines, the GL261 orthotopic mouse models of glioblastoma, and HK-374 patient-derived orthotopic xenografts, we tested the effect of radiation and the dopamine receptor antagonist quetiapine on glioblastoma self-renewal in vitro and survival in vivo. A possible resistance mechanism was investigated using RNA-sequencing. The blood-brain-barrier-penetrating statin atorvastatin was used to overcome this resistance mechanism. All statistical tests were 2-sided.
RESULTS
Treatment of glioma cells with the dopamine receptor antagonist quetiapine reduced glioma cell self-renewal in vitro, and combined treatment of mice with quetiapine and radiation prolonged the survival of glioma-bearing mice. The combined treatment induced the expression of genes involved in cholesterol biosynthesis. This rendered GL261 and HK-374 orthotopic tumors vulnerable to simultaneous treatment with atorvastatin and further statistically significantly prolonged the survival of C57BL/6 (n = 10 to 16 mice per group; median survival not reached; log-rank test, P < .001) and NOD Scid gamma mice (n = 8 to 21 mice per group; hazard ratio = 3.96, 95% confidence interval = 0.29 to 12.40; log-rank test, P < .001), respectively.
CONCLUSIONS
Our results indicate promising therapeutic efficacy with the triple combination of quetiapine, atorvastatin, and radiation treatment against glioblastoma without increasing the toxicity of radiation. With both drugs readily available for clinical use, our study could be rapidly translated into a clinical trial.
Topics: Animals; Brain Neoplasms; Cell Line, Tumor; Cholesterol; Dopamine Antagonists; Glioblastoma; Humans; Mice; Mice, Inbred C57BL; Xenograft Model Antitumor Assays
PubMed: 33556960
DOI: 10.1093/jnci/djab018 -
Psychopharmacology Dec 2016Animal research has demonstrated a role of dopamine D1 and D3 receptors in cocaine reward and seeking.
RATIONALE
Animal research has demonstrated a role of dopamine D1 and D3 receptors in cocaine reward and seeking.
PURPOSE AND METHODS
Here, we investigated the potential interaction of these two dopamine receptors in cue-induced reinstatement of cocaine seeking, cocaine conditioned place preference (CPP), and cocaine self-administration in rats.
RESULTS
The co-administration of a D3 receptor antagonist, NGB 2904 and a D1 partial agonist, SKF 77434, of doses which when administered individually produced no significant effects, prior to reinstatement or CPP tests significantly reduced lever pressing and time spent in the cocaine-paired environment, suggesting synergistic effects of the combined compounds on cocaine seeking. When given to rats self-administering cocaine under a progressive ratio schedule of reinforcement doses of NGB 2904 which were ineffective alone significantly enhanced the break point-reducing effects of SKF 77434.
CONCLUSIONS
Our results indicate that the combined treatment with a D1 receptor partial agonist and D3 receptor antagonist produces robust decreases in cocaine seeking and reward. This suggests an interaction between dopamine D1 and D3 receptors in cocaine-related behaviors.
Topics: Animals; Cocaine; Cocaine-Related Disorders; Disease Models, Animal; Dopamine Antagonists; Drug Therapy, Combination; Drug-Seeking Behavior; Fluorenes; Male; Piperazines; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D1; Receptors, Dopamine D3; Reinforcement, Psychology; Reward
PubMed: 27582181
DOI: 10.1007/s00213-016-4420-9 -
The European Journal of Neuroscience Jan 2017This review updates the existing knowledge suggesting a role for the D3 receptor in schizophrenia and drug addiction. The D3 receptor is expressed in brain regions... (Review)
Review
This review updates the existing knowledge suggesting a role for the D3 receptor in schizophrenia and drug addiction. The D3 receptor is expressed in brain regions controlling reward, emotions, and motivation. Antipsychotics bind in vitro to the D3 receptor with similar affinity as to the D2 receptor, and occupancy of D3 receptors in vivo by these compounds given acutely at clinical dosage have been demonstrated in Positron Emission Tomography (PET) studies. The D3 receptor modulates glutamatergic pathways from the prefrontal cortex to subcortical areas, either directly by interacting with N-methyl-D-aspartate (NMDA) receptors in the nucleus accumbens, or indirectly by controlling dopamine release from ventral tegmental area neurons. In animals, D3 receptor antagonists reverse behavioral manifestations of NMDA receptor blockade and improve cognitive performances in various paradigms. Two D3 receptor-selective compounds have reached clinical trials in schizophrenia, with negative results seemingly due to insufficient target engagement; the results with a third compound, F17464, have not been disclosed yet. There is converging evidence that D3 receptors do not control the reinforcing effects of drugs of abuse (with the exception of alcohol under low requirement), but rather affects the motivation to take the drugs under high requirement, reactivity to drug-associated cues, and drug-seeking behaviors triggered by stimuli associated with relapse in humans. D3 receptor expression measured by PET is upregulated in humans with various drug addictions. A single administration of the D3 receptor-selective antagonist, GSK598809, in humans transiently alleviated craving in smokers after overnight abstinence. The clinical development of D3-selective compounds will benefit from initial assessment of target engagement through the use of PET.
Topics: Animals; Brain; Dopamine Antagonists; Drug-Seeking Behavior; Humans; Receptors, Dopamine D2; Receptors, Dopamine D3; Substance-Related Disorders
PubMed: 27600596
DOI: 10.1111/ejn.13390 -
Neuropsychopharmacology : Official... Jun 2023Balancing the exploration of new options and the exploitation of known options is a fundamental challenge in decision-making, yet the mechanisms involved in this balance... (Randomized Controlled Trial)
Randomized Controlled Trial
Balancing the exploration of new options and the exploitation of known options is a fundamental challenge in decision-making, yet the mechanisms involved in this balance are not fully understood. Here, we aimed to elucidate the distinct roles of dopamine and noradrenaline in the exploration-exploitation tradeoff during human choice. To this end, we used a double-blind, placebo-controlled design in which participants received either a placebo, 400 mg of the D2/D3 receptor antagonist amisulpride, or 40 mg of the β-adrenergic receptor antagonist propranolol before they completed a virtual patch-foraging task probing exploration and exploitation. We systematically varied the rewards associated with choice options, the rate by which rewards decreased over time, and the opportunity costs it took to switch to the next option to disentangle the contributions of dopamine and noradrenaline to specific choice aspects. Our data show that amisulpride increased the sensitivity to all of these three critical choice features, whereas propranolol was associated with a reduced tendency to use value information. Our findings provide novel insights into the specific roles of dopamine and noradrenaline in the regulation of human choice behavior, suggesting a critical involvement of dopamine in directed exploration and a role of noradrenaline in more random exploration.
Topics: Humans; Dopamine; Amisulpride; Norepinephrine; Propranolol; Dopamine Antagonists; Decision Making; Reward
PubMed: 36522404
DOI: 10.1038/s41386-022-01517-9 -
Journal of Neural Transmission (Vienna,... Feb 2017The psychostimulant, methylphenidate (MPD), is the first line treatment as a pharmacotherapy to treat behavioral disorders such as attention deficit hyperactivity...
The psychostimulant, methylphenidate (MPD), is the first line treatment as a pharmacotherapy to treat behavioral disorders such as attention deficit hyperactivity disorder (ADHD). MPD is commonly misused in non-ADHD (normal) youth and young adults both as a recreational drug and for cognitive enhancing effects to improve their grades. MPD is known to act on the reward circuit; including the caudate nucleus (CN). The CN is comprised of medium spiny neurons containing largely dopamine (DA) D1 and D2 receptors. It has been widely shown that the DA system plays an important role in the response to MPD exposure. We investigated the role of both D1 and D2 DA receptors in the CN response to chronic MPD administration using specific D1 and D2 DA antagonist. Four groups of young adult, male SD rats were used: a saline (control) and three MPD dose groups (0.6, 2.5, and 10.0 mg/kg). The experiment lasted 11 consecutive days. Each MPD dose group was randomly divided into two subgroups to receive either a 0.4 mg/kg SCH-23390 selective D1 DA antagonist or a 0.3 mg/kg raclopride selective D2 DA antagonist prior to their final (repetitive) MPD rechallenge administration. It was observed that selective D1 DA antagonist (SCH-23390) given 30 min prior to the last MPD exposure at ED11 partially reduced or prevented the effect induced by MPD exposure in CN neuronal firing rates across all MPD doses. Selective D2 DA antagonist (raclopride) resulted in less obvious trends; some CN neuronal firing rates exhibited a slight increase in all MPD doses.
Topics: Action Potentials; Animals; Benzazepines; Caudate Nucleus; Central Nervous System Stimulants; Dopamine Antagonists; Dose-Response Relationship, Drug; Electrodes, Implanted; Male; Methylphenidate; Neurons; Psychotropic Drugs; Raclopride; Random Allocation; Rats, Sprague-Dawley; Receptors, Dopamine D1; Receptors, Dopamine D2
PubMed: 27853928
DOI: 10.1007/s00702-016-1647-x