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Neurochemistry International Jul 2024Although the output of the lateral habenula (LHb) controls the activity of midbrain dopaminergic and serotonergic systems, which are implicated in the pathophysiology of...
Although the output of the lateral habenula (LHb) controls the activity of midbrain dopaminergic and serotonergic systems, which are implicated in the pathophysiology of anxiety, it is not clear the role of LHb 5-HT receptors in regulation of anxiety-like behaviors, particularly in Parkinson's disease-related anxiety. In this study, unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta in rats induced anxiety-like behaviors, led to decreased normalized δ power and increased normalized θ power in the LHb, and decreased dopamine (DA) level in the prelimbic cortex (PrL) compared with sham rats. Down-regulation of LHb 5-HT receptors by RNA interference produced anxiety-like effects, decreased normalized δ power and increased normalized θ power in the LHb in both sham and lesioned rats. Further, intra-LHb injection of 5-HT receptor agonist CP93129 induced anxiolytic-like responses, increased normalized δ power and decreased normalized θ power in the LHb, and increased DA and serotonin (5-HT) release in the PrL; conversely, 5-HT receptor antagonist SB216641 produced anxiety-like effects, decreased normalized δ power and increased normalized θ power in the LHb, and decreased DA and 5-HT release in the PrL in sham and lesioned rats. Additionally, effects of CP93129 and SB216641 on the behaviors, normalized δ and θ power in the LHb, and DA and 5-HT release in the PrL were decreased in lesioned rats, which were consistent with down-regulation of LHb 5-HT receptors after DA depletion. Collectively, these findings suggest that 5-HT receptors in the LHb are involved in the regulation of anxiety-like behaviors.
Topics: Animals; Habenula; Receptor, Serotonin, 5-HT1B; Male; Anxiety; Rats; Rats, Sprague-Dawley; Oxidopamine; Parkinsonian Disorders; Dopamine; Behavior, Animal
PubMed: 38750961
DOI: 10.1016/j.neuint.2024.105766 -
Neuropharmacology Sep 2024Emerging evidence suggests an important role of astrocytes in mediating behavioral and molecular effects of commonly misused drugs. Passive exposure to nicotine alters...
Fluorocitrate inhibition of astrocytes reduces nicotine self-administration and alters extracellular levels of glutamate and dopamine within the nucleus accumbens in male wistar rats.
Emerging evidence suggests an important role of astrocytes in mediating behavioral and molecular effects of commonly misused drugs. Passive exposure to nicotine alters molecular, morphological, and functional properties of astrocytes. However, a potential involvement of astrocytes in nicotine reinforcement remains largely unexplored. The overall hypothesis tested in the current study is that astrocytes play a critical role in nicotine reinforcement. Protein levels of the astrocyte marker glial fibrillary acidic protein (GFAP) were examined in key mesocorticolimbic regions following chronic nicotine intravenous self-administration. Fluorocitrate, a metabolic inhibitor of astrocytes, was tested for its effects on behaviors related to nicotine reinforcement and relapse. Effects of fluorocitrate on extracellular neurotransmitter levels, including glutamate, GABA, and dopamine, were determined with microdialysis. Chronic nicotine intravenous self-administration increased GFAP expression in the nucleus accumbens core (NACcr), but not other key mesocorticolimbic regions, compared to saline intravenous self-administration. Both intra-ventricular and intra-NACcr microinjection of fluorocitrate decreased nicotine self-administration. Intra-NACcr fluorocitrate microinjection also inhibited cue-induced reinstatement of nicotine seeking. Local perfusion of fluorocitrate decreased extracellular glutamate levels, elevated extracellular dopamine levels, but did not alter extracellular GABA levels in the NACcr. Fluorocitrate did not alter basal locomotor activity. These results indicate that nicotine reinforcement upregulates the astrocyte marker GFAP expression in the NACcr, metabolic inhibition of astrocytes attenuates nicotine reinforcement and relapse, and metabolic inhibition of astrocytes disrupts extracellular dopamine and glutamate transmission. Overall, these findings suggest that astrocytes play an important role in nicotine reinforcement and relapse, potentially through regulation of extracellular glutamate and dopamine neurotransmission.
Topics: Animals; Nucleus Accumbens; Astrocytes; Nicotine; Male; Glutamic Acid; Self Administration; Dopamine; Citrates; Rats, Wistar; Rats; Glial Fibrillary Acidic Protein; Nicotinic Agonists; Microdialysis; Reinforcement, Psychology; gamma-Aminobutyric Acid
PubMed: 38750804
DOI: 10.1016/j.neuropharm.2024.110001 -
Pakistan Journal of Pharmaceutical... Jan 2024Aripiprazole (ARI), an antipsychotic having low solubility and stability. To overcome this, formation of binary and ternary using inclusion complexes of... (Comparative Study)
Comparative Study
Aripiprazole (ARI), an antipsychotic having low solubility and stability. To overcome this, formation of binary and ternary using inclusion complexes of Methyl-β-cyclodextrin (MβCD) /Hydroxy propyl beta cyclodextrin (HPβCD) and L-Arginine (ARG)/ Lysine (LYS) are analyzed by dissolution testing and phase stability study along with their complexation efficacy and solubility constants made by physical mixing. Inclusion complexes with ARG were better than LYS and prepared by solvent evaporation and lyophilization method as well. They are characterized by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (AT-FTIR), X-ray powder diffractometry (XRD), Differential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM) and Thermal gravimetric analysis (TGA). The bond shifting in AT-FTIR confirmed the molecular interactions between host and guest molecules. The SEM images also confirmed a complete change of drug morphology in case of ternary inclusion complexes prepared by lyophilization method for both the polymers. ARI: MβCD: ARG when used in the specific molar ratio of 1:1:0.27 by prepared by lyophilization method has 18 times best solubility while ARI:HPβCD:ARG was 7 times best solubility than pure drug making MβCD a better choice than HPβCD. Change in the molar ratio will cause loss of stability or solubility. Solvent evaporation gave significant level of solubility but less stability.
Topics: Aripiprazole; Arginine; Solubility; beta-Cyclodextrins; 2-Hydroxypropyl-beta-cyclodextrin; Lysine; Spectroscopy, Fourier Transform Infrared; Calorimetry, Differential Scanning; X-Ray Diffraction; Freeze Drying; Antipsychotic Agents; Drug Stability; Microscopy, Electron, Scanning; Drug Compounding; Chemistry, Pharmaceutical
PubMed: 38747276
DOI: No ID Found -
Movement Disorders Clinical Practice May 2024Levodopa-induced dyskinesias (LID) are frequent in Parkinson's disease (PD).
BACKGROUND
Levodopa-induced dyskinesias (LID) are frequent in Parkinson's disease (PD).
OBJECTIVE
To analyze the change in the frequency of LID over time, identify LID related factors, and characterize how LID impact on patients' quality of life (QoL).
PATIENTS AND METHODS
PD patients from the 5-year follow-up COPPADIS cohort were included. LID were defined as a non-zero score in the item "Time spent with dyskinesia" of the Unified Parkinson's Disease Rating Scale-part IV (UPDRS-IV). The UPDRS-IV was applied at baseline (V0) and annually for 5 years. The 39-item Parkinson's disease Questionnaire Summary Index (PQ-39SI) was used to asses QoL.
RESULTS
The frequency of LID at V0 in 672 PD patients (62.4 ± 8.9 years old; 60.1% males) with a mean disease duration of 5.5 ± 4.3 years was 18.9% (127/672) and increased progressively to 42.6% (185/434) at 5-year follow-up (V5). The frequency of disabling LID, painful LID, and morning dystonia increased from 6.9%, 3.3%, and 10.6% at V0 to 17.3%, 5.5%, and 24% at V5, respectively. Significant independent factors associated with LID (P < 0.05) were a longer disease duration and time under levodopa treatment, a higher dose of levodopa, a lower weight and dose of dopamine agonist, pain severity and the presence of motor fluctuations. LID at V0 (β = 0.073; P = 0.027; R = 0.62) and to develop disabling LID at V5 (β = 0.088; P = 0.009; R = 0.73) were independently associated with a higher score on the PDQ-39SI.
CONCLUSION
LID are frequent in PD patients. A higher dose of levodopa and lower weight were factors associated to LID. LID significantly impact QoL.
PubMed: 38747234
DOI: 10.1002/mdc3.14056 -
Archives of Toxicology May 2024The phenylethylamine, 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy'), is the prototypical example of an entactogen. Its original placement in highly restrictive... (Review)
Review
The phenylethylamine, 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy'), is the prototypical example of an entactogen. Its original placement in highly restrictive drug usage categories in the US and UK, led to an inevitable restriction on MDMA neuroscience research and treatment. The dominant pharmacological effects of MDMA are its properties of release and inhibition of reuptake of amine neurotransmitter transporters for dopamine, norepinephrine, and serotonin. MDMA is an agonist of a wide range of receptors; its mood-altering effects are mediated via 5-HT receptors; this receptor may also mediate its effects on body temperature, analgesia, and anxiolytic properties. The mechanisms underlying MDMA's entactogenic properties of sociability and interpersonal closeness are not known but release and involvement of oxytocin, a peptide thought by some to be involved in social bonding, has been suggested. Adverse effects of MDMA are mostly transient; acute multiorgan adverse effects occurring during raves or crowded dance gatherings include dehydration, hyperthermia, seizures, rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure. Deaths following MDMA taken by itself are rare compared to fatalities following coadministration with other drugs. A recent FDA-approved phase 3 clinical trial of MDMA for post-traumatic stress disorder (PTSD) led to the conclusion that MDMA-assisted therapy represents a potential breakthrough treatment meriting expedited clinical evaluation. Despite the ongoing deliberations by the FDA and EMA for approval of MDMA treatment of PTSD, the Australian Therapeutic Goods Administration (TGA) recently announced that after an evaluation of the therapeutic value, benefits, and risks of MDMA, it will permit its prescribing for the treatment of PTSD. Further examples of regulatory relaxation toward MDMA-assisted psychotherapy are underway. These include the FDA's recently approved clinical trial to assess MDMA's efficacy in the treatment of "asociality" in patients with schizophrenia and an open trial of MDMA treatment for alcohol-use disorder which showed decreased alcohol consumption. There are also ongoing studies on the little understood startle response, anxiety associated with life-threatening illness, and social anxiety in autistic adults.
PubMed: 38743292
DOI: 10.1007/s00204-024-03765-8 -
Surgical Neurology International 2024Giant prolactinomas are rare; among them, the amyloidogenic variant, prolactinomas with extensive spherical amyloid deposits, are rare, with only 30 cases reported with...
BACKGROUND
Giant prolactinomas are rare; among them, the amyloidogenic variant, prolactinomas with extensive spherical amyloid deposits, are rare, with only 30 cases reported with recommendations of surgical management contrary to the routine prolactinoma's medical management.
CASE DESCRIPTION
We report here a case of giant amyloidogenic prolactinoma in a 32-year-old male patient who had a very atypical presentation in terms of clinical, radiological, and pathological features and responded to dopamine agonist therapy like a normal prolactinoma.
CONCLUSION
Amyloidogenic giant prolactinomas are rare. Contrary to usual belief, even they remain medically responsive; however, more literature is required to decide their ideal management.
PubMed: 38741982
DOI: 10.25259/SNI_150_2024 -
Experimental Cell Research Jun 2024Dopamine D2 receptors (D2Rs) play crucial roles in regulating diverse physiological functions of the central nervous system and peripheral organs. D2Rs are also...
Dopamine D2 receptors (D2Rs) play crucial roles in regulating diverse physiological functions of the central nervous system and peripheral organs. D2Rs are also expressed in mammary glands. However, which cell types express D2Rs and whether they are involved in milk production remains unclear. The present findings revealed that D2Rs are expressed in the apical regions of the lateral membranes of mammary epithelial cells (MECs) in lactating mice. We also investigated the effects of the D2R agonist bromocriptine and/or antagonist domperidone on intracellular cAMP levels, milk protein production, and apoptosis in a lactation culture model of MECs that produce major milk components like lactating MECs in vivo. We found that bromocriptine decreased intracellular cAMP levels, whereas domperidone dose-dependently neutralized this effect. Bromocriptine also inhibited casein and lactoferrin production and suppressed activities of STAT5 and glucocorticoid receptors (GRs). Domperidone neutralized the inhibition of casein production as well as STAT5 and GR inactivation induced by bromocriptine. Furthermore, D2R activation by bromocriptine induced apoptosis and inactivated ERK, a signaling molecule responsible for promoting cell proliferation and survival. Domperidone attenuated ERK inactivation and apoptosis induced by bromocriptine. These findings suggest that D2Rs play regulatory roles in milk protein production and apoptosis in MECs.
Topics: Animals; Female; Mice; Apoptosis; Bromocriptine; Cells, Cultured; Cyclic AMP; Domperidone; Epithelial Cells; Lactation; Mammary Glands, Animal; Milk Proteins; Receptors, Dopamine D2; STAT5 Transcription Factor
PubMed: 38740167
DOI: 10.1016/j.yexcr.2024.114090 -
Neurobiology of Learning and Memory Jul 2024Systemic manipulations that enhance dopamine (DA) transmission around the time of fear extinction can strengthen fear extinction and reduce conditioned fear relapse....
Systemic manipulations that enhance dopamine (DA) transmission around the time of fear extinction can strengthen fear extinction and reduce conditioned fear relapse. Prior studies investigating the brain regions where DA augments fear extinction focus on targets of mesolimbic and mesocortical DA systems originating in the ventral tegmental area, given the role of these DA neurons in prediction error. The dorsal striatum (DS), a primary target of the nigrostriatal DA system originating in the substantia nigra (SN), is implicated in behaviors beyond its canonical role in movement, such as reward and punishment, goal-directed action, and stimulus-response associations, but whether DS DA contributes to fear extinction is unknown. We have observed that chemogenetic stimulation of SN DA neurons during fear extinction prevents the return of fear in contexts different from the extinction context, a form of relapse called renewal. This effect of SN DA stimulation is mimicked by a DA D1 receptor (D1R) agonist injected into the DS, thus implicating DS DA in fear extinction. Different DS subregions subserve unique functions of the DS, but it is unclear where in the DS D1R agonist acts during fear extinction to reduce renewal. Furthermore, although fear extinction increases neural activity in DS subregions, whether neural activity in DS subregions is causally involved in fear extinction is unknown. To explore the role of DS subregions in fear extinction, adult, male Long-Evans rats received microinjections of either the D1R agonist SKF38393 or a cocktail consisting of GABA/GABA receptor agonists muscimol/baclofen selectively into either dorsomedial (DMS) or dorsolateral (DLS) DS subregions immediately prior to fear extinction, and extinction retention and renewal were subsequently assessed drug-free. While increasing D1R signaling in the DMS during fear extinction did not impact fear extinction retention or renewal, DMS inactivation reduced later renewal. In contrast, DLS inactivation had no effect on fear extinction retention or renewal but increasing D1R signaling in the DLS during extinction reduced fear renewal. These data suggest that DMS and DLS activity during fear extinction can have opposing effects on later fear renewal, with the DMS promoting renewal and the DLS opposing renewal. Mechanisms through which the DS could influence the contextual gating of fear extinction are discussed.
Topics: Animals; Fear; Extinction, Psychological; Male; Rats; Corpus Striatum; Receptors, Dopamine D1; Dopamine Agonists; Conditioning, Classical; Dopaminergic Neurons; Substantia Nigra; Rats, Long-Evans; Dopamine
PubMed: 38735637
DOI: 10.1016/j.nlm.2024.107937 -
International Journal of Molecular... Apr 2024There are currently no disease-modifying therapies for Parkinson's disease (PD), a progressive neurodegenerative disorder associated with dopaminergic neuronal loss.... (Review)
Review
There are currently no disease-modifying therapies for Parkinson's disease (PD), a progressive neurodegenerative disorder associated with dopaminergic neuronal loss. There is increasing evidence that endogenous dopamine (DA) can be a pathological factor in neurodegeneration in PD. Tyrosine hydroxylase (TH) is the key rate-limiting enzyme for DA generation. Drugs that inhibit TH, such as alpha-methyltyrosine (α-MT), have recently been shown to protect against neurodegeneration in various PD models. DA receptor agonists can activate post-synaptic DA receptors to alleviate DA-deficiency-induced PD symptoms. However, DA receptor agonists have no therapeutic effects against neurodegeneration. Thus, a combination therapy with DA receptor agonists plus TH inhibitors may be an attractive therapeutic approach. TH inhibitors can protect and promote the survival of remaining dopaminergic neurons in PD patients' brains, whereas DA receptor agonists activate post-synaptic DA receptors to alleviate PD symptoms. Additionally, other PD drugs, such as N-acetylcysteine (NAC) and anticholinergic drugs, may be used as adjunctive medications to improve therapeutic effects. This multi-drug cocktail may represent a novel strategy to protect against progressive dopaminergic neurodegeneration and alleviate PD disease progression.
Topics: Animals; Humans; Dopamine; Dopamine Agonists; Dopaminergic Neurons; Drug Therapy, Combination; Enzyme Inhibitors; Parkinson Disease; Tyrosine 3-Monooxygenase
PubMed: 38731862
DOI: 10.3390/ijms25094643 -
BMC Psychiatry May 2024Restless arms syndrome (RAS) is the most common variant of restless legs syndrome (RLS), which is easy to be ignored in clinical practice due to the lack of specific...
BACKGROUND
Restless arms syndrome (RAS) is the most common variant of restless legs syndrome (RLS), which is easy to be ignored in clinical practice due to the lack of specific diagnostic criteria. When effective therapeutic agents induced RAS and symptoms persisted after briefly observation, clinicians will face the challenge of weighing efficacy against side effects.
CASE PRESENTATION
A 67-year-old woman was admitted to a geriatric psychiatric ward with depression. Upon admission, the escitalopram dose was reduced from 15 mg to 10 mg per day, and the duloxetine dose was increased from 60 mg to 80 mg per day. The next night before bedtime, she developed itching and creeping sensations deep inside bilateral shoulders and arms, with the urge to move, worsening at rest, and alleviation after hammering. The symptoms persisted when escitalopram was discontinued. A history of RLS was confirmed. Treatment with 40 mg of duloxetine and 0.125 mg of pramipexole significantly improved depression, and the paresthesia disappeared, with no recurrence occurring 6 months after discharge.
DISCUSSION AND CONCLUSIONS
This case suggests that psychiatrists should pay attention to RLS variants when increasing doses of duloxetine. Long-term improvement can be achieved through dosage reduction combined with dopaminergic drugs instead of immediate discontinuation.
Topics: Aged; Female; Humans; Antidepressive Agents; Duloxetine Hydrochloride; Phenotype; Pramipexole; Restless Legs Syndrome; Serotonin and Noradrenaline Reuptake Inhibitors
PubMed: 38730422
DOI: 10.1186/s12888-024-05763-7