Structural pharmacology and therapeutic potential of 5-methoxytryptamines.

Psychedelic substances such as lysergic acid diethylamide (LSD) and psilocybin show potential for the treatment of various neuropsychiatric disorders1-3. These compounds are thought to mediate their hallucinogenic and therapeutic effects through the serotonin (5-hydroxytryptamine (5-HT)) receptor 5-HT2A (ref. 4). However, 5-HT1A also plays a part in the behavioural effects of tryptamine hallucinogens5, particularly 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), a psychedelic found in the toxin of Colorado River toads6. Although 5-HT1A is a validated therapeutic target7,8, little is known about how psychedelics engage 5-HT1A and which effects are mediated by this receptor. Here we map the molecular underpinnings of 5-MeO-DMT pharmacology through five cryogenic electron microscopy (cryo-EM) structures of 5-HT1A, systematic medicinal chemistry, receptor mutagenesis and mouse behaviour. Structure-activity relationship analyses of 5-methoxytryptamines at both 5-HT1A and 5-HT2A enable the characterization of molecular determinants of 5-HT1A signalling potency, efficacy and selectivity. Moreover, we contrast the structural interactions and in vitro pharmacology of 5-MeO-DMT and analogues to the pan-serotonergic agonist LSD and clinically used 5-HT1A agonists. We show that a 5-HT1A-selective 5-MeO-DMT analogue is devoid of hallucinogenic-like effects while retaining anxiolytic-like and antidepressant-like activity in socially defeated animals. Our studies uncover molecular aspects of 5-HT1A-targeted psychedelics and therapeutics, which may facilitate the future development of new medications for neuropsychiatric disorders.

Efficacy and tolerability of 100†mg of lasmiditan for migraine: A multi-center, prospective observational real-world study in Japan.

BACKGROUND: Real-world data on the effectiveness and safety of lasmiditan, a new medication for acute migraine attacks, is necessary. METHODS: We performed a prospective, observational, multi-center, real-world study. A total of 48 patients with migraine (44 females, 44.6 ± 12.9 years old) were included in this study. RESULTS: Twenty-three patients (47.9%) reported they were headache-free two hours after taking lasmiditan and were categorized into the responder group. In total, 44 patients (91.7%) experienced at least one side effect within two hours of taking the medication. Dizziness, somnolence, malaise, nausea, and palpitations were reported by 56.3% (n = 27), 45.8% (n = 22), 37.5% (n = 18), 20.8% (n = 10), and 14.6% (n = 7) of patients respectively. Of 48 patients, 20 (41.7%) indicated that they preferred lasmiditan to their previous acute treatment. There were no predictive factors for efficacy. CONCLUSION: This real-world study demonstrated the efficacy and safety of lasmiditan. More than 90% of patients experienced side effects from lasmiditan. Approximately 40% of patients preferred lasmiditan despite the occurrence of side effects.

Serotonin regulation of mitochondria in kidney diseases.

Serotonin, while conventionally recognized as a neurotransmitter in the CNS, has recently gained attention for its role in the kidney. Specifically, serotonin is not only synthesized in the kidney, but it also regulates glomerular function, vascular resistance, and mitochondrial homeostasis. Because of serotonin's importance to mitochondrial health, this review is focused on the role of serotonin and its receptors in mitochondrial function in the context of acute kidney injury, chronic kidney disease, and diabetic kidney disease, all of which are characterized by mitochondrial dysfunction and none of which has approved pharmacological treatments. Evidence indicates that activation of certain serotonin receptors can stimulate mitochondrial biogenesis (MB) and restore mitochondrial homeostasis, resulting in improved renal function. Serotonin receptor agonists that induce MB are therefore of interest as potential therapeutic strategies for renal injury and disease. SIGNIFICANCE STATEMENT: Mitochondrial dysfunction is associated with many human renal diseases such as acute kidney injury, chronic kidney disease, and diabetic kidney disease, which are associated with increased morbidity and mortality. Unfortunately, none of these pathologies has an FDA-approved pharmacological intervention, underscoring the urgency of identifying new therapeutics for such disorders. Studies show that induction of mitochondrial biogenesis via serotonin (5-hydroxytryptamine, 5-HT) receptors reduces kidney injury markers, restores mitochondrial and renal function after kidney injury, and decreases mortality, suggesting that targeting 5-HT receptors may be a promising therapeutic avenue for mitochondrial dysfunction in kidney diseases. While numerous reviews describe the importance of mitochondria and mitochondrial quality control mechanisms in kidney disease, the relevance of 5-HT receptor-mediated mitochondrial metabolic modulation in the kidney has yet to be thoroughly explored.

Long-term treatment with lasmiditan in patients with migraine: post hoc analysis of treatment patterns and outcomes from the open-label extension of the CENTURION randomized trial.

BACKGROUND: The objective of this analysis was to gain new insights into the patient characteristics and other factors associated with lasmiditan usage and clinical outcomes under conditions resembling the real-world setting. METHODS: This was a post hoc analysis of data from the 12-month, open-label extension (OLE) of the phase 3, double-blind, randomized, controlled CENTURION trial, which examined the efficacy and safety of lasmiditan as acute treatment across four migraine attacks. Patients completing the main study who treated ≥ 3 attacks could continue in the OLE. The initial lasmiditan dose was 100 mg, with dose adjustments to 50 mg or 200 mg allowed at the investigator's discretion. Patient and clinical characteristics were summarized by dosing pattern and completion status. Safety was assessed based on adverse event (AE) frequency by number of doses. RESULTS: In total, 445 patients treated ≥ 1 migraine attacks with lasmiditan during the OLE, 321 of whom (72.1%) completed the study. Forty-seven percent of patients remained on the 100-mg initial dose during the OLE whereas 20.2% used both 100 mg and 50 mg, 30.6% used both 100 mg and 200 mg, and 6 (1.3%) used multiple dose levels. All dosing patterns were associated with clinical and patient-reported improvement; however, the 100-mg group had the highest proportion of patients reporting improvement in the Patient Global Impression of Change - Migraine Headache Condition (56.5% vs 33.4%-52.2%). In comparison, all three groups that made dose adjustments had higher rates of completion compared to the 100-mg group (72.1%-83.3% vs 68.9%). The frequency of AEs decreased with continued use of lasmiditan. Concomitant triptans and lasmiditan use did not increase AE frequency. CONCLUSIONS: Based on high persistence and patient satisfaction rates, the 100-mg dose appears optimal for most patients. For those who adjusted dose levels, dose adjustments appeared beneficial to improve efficacy or tolerability, retaining patients on treatment. Collectively, the data suggest that patients who experienced efficacy continued to use lasmiditan regardless of the occurrence or frequency of AEs, and continued use appeared associated with fewer AEs. TRIAL REGISTRATION: European Union Drug Regulating Authorities Clinical Trials Database (EudraCT): 2018-001661-17; ClinicalTrials.gov: NCT03670810; registration date: September 12, 2018.

An update on migraine: Current and new treatment options.

ABSTRACT: Migraine headache is a common and potentially debilitating disorder often treated by physician associates/assistants (PAs) and other providers. With the recent advances in new drugs and device technology for the treatment of migraine, the American Headache Society has released a consensus statement on both preventive and acute strategies for clinical practice. The US FDA has recently approved various types of medications and devices for the treatment and prevention of migraine attacks including several calcitonin gene-related peptide (CGRP) receptor inhibitors, a selective serotonin receptor agonist (SSRA), noninvasive vagus nerve stimulation (nVNS), external trigeminal nerve stimulation (e-TNS), and external concurrent occipital and trigeminal neurostimulation (eCOT-NS), among other pharmacologic and nonpharmacologic options. This article provides a review of migraine prevention and acute treatment protocol, highlighting new approaches to both.

Tegaserod: What's Old Is New Again.

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are common gastrointestinal disorders imposing considerable impact on the quality of life and well-being of affected individuals. A paucity of evidence-based treatment options exist for CIC and IBS-C sufferers. Tegaserod, a 5-HT4 agonist, has a substantial body of preclinical and clinical study evidence to support its beneficial role in modulating sensorimotor function of the luminal gastrointestinal tract. Tegaserod was first approved for use by the U.S. Food and Drug Administration for the management of IBS-C and CIC in 2002 and 2004, respectively. Tegaserod enjoyed a successful uptake in the management of these disorders during its first several years of availability in the United States, but was later withdrawn from the market in 2007 over concerns related to adverse cardiovascular events. Since then, additional safety data has been generated, and following a resubmission and review by the Food and Drug Administration, in April 2019, tegaserod was once again approved for use in IBS-C under a more restricted labeling, confining use to women under 65 years of age without heart disease or additional cardiovascular risk factors. This review summarizes the regulatory journey of tegaserod and details the existing pharmacokinetic, physiologic, clinical, and safety data of tegaserod generated over the last 2 decades. The discussion also examines the future of tegaserod in the treatment of these constipation disorders, as well as its potential role in other related disorders of brain-gut interaction.

The 5-HT1A receptor agonist, 8-OH-DPAT, attenuates long-lasting pain in imiquimod-induced psoriasis in mice.

Psoriasis pain is a common symptom underestimated and rarely evaluated in psoriasis clinical trials. This work aimed to investigate whether the development of secondary chronic allodynia and hyperalgesia in the imiquimod (IMQ)-induced psoriasis mice model could be modulated by anti-inflammatory agents and compound 48/80 (C48/80) and to determine whether the activation of 5-HT1A receptor modulates these nociceptive behaviours. C57BL/6 male mice were treated with 5% IMQ for 7 days. The paw withdrawal responses to von Frey filaments (10 and 250 mN) were used to assess the allodynia and hyperalgesia. Nociceptive behaviours were also evaluated using ketorolac 15 mg/kg s.c., adalimumab 10 mg/kg s.c. and C48/80 10 mg/kg i.p. Then, the serum serotonin and the impact of 8-OH-DPAT (1 mg/kg s.c), a 5-HT1A receptor agonist, on long-lasting pain were examined. Mice receiving IMQ showed enhanced nociception, which decreased with all tested compounds. The serum serotonin in the IMQ group showed a significant decrease (947.042 ng/ml) regarding the control group (1143.68 ng/ml). The pretreatment with 8-OH-DPAT alleviated pain-related behaviours. These results suggest that the long-lasting pain resulting from psoriasis inflammation is also associated with the serotonergic system. The 5-HT1A receptor should be further explored as a potential therapeutic target for psoriasis pain modulation.

Lasmiditan efficacy in the acute treatment of migraine was independent of prior response to triptans: Findings from the CENTURION study.

BACKGROUND: A significant proportion of triptan users exhibit an insufficient response or inadequate tolerability to a triptan, and some may develop a contraindication. Lasmiditan, a selective 5-HT1F receptor agonist, may be an option for these individuals. We assessed lasmiditan efficacy in a subgroup of patients in CENTURION (Phase 3 migraine consistency study) who exhibited an insufficient response to triptans, including a subgroup with insufficient response due to efficacy only. METHODS: Patients were randomized to lasmiditan 200 mg for four attacks, lasmiditan 100 mg for four attacks, or placebo for three and lasmiditan 50 mg for one attack. Triptan insufficient responders were pre-defined as patients with insufficient efficacy or tolerability, or who developed a contraindication. RESULTS: In triptan insufficient responders, lasmiditan was superior to placebo (p < 0.05) for pain freedom beginning at 1 h (both doses); pain relief beginning at 0.5 (200 mg) or 1 h (100 mg); migraine-related disability freedom, much/very much better on the Patient Global Impression of Change, and most bothersome symptom freedom at 2 h; sustained pain freedom; and need for rescue medication. Lasmiditan showed benefit for consistency of effect across attacks for 2-h pain freedom and pain relief. Findings were similar in triptan responders and triptan naïve patients and when the triptan insufficient response definition was based on efficacy only. CONCLUSIONS: Lasmiditan was efficacious across multiple clinically relevant endpoints in the acute treatment of migraine independent of prior response to triptans.Trial Registration: CENTURION (NCT03670810); SAMURAI (NCT02439320); SPARTAN (NCT02605174).

Ditans: a new prospective for the therapy of migraine attack?

INTRODUCTION: Migraine attack is characterized by disabling pain and associated symptoms. Triptans represent the "gold standard" therapy, but cardiac subjects have significant limitations for this approach. New drug families are under consideration to expand therapeutic offerings, especially in the presence of contraindications or for non-responsive patients. This review aimed to analyze studies related to the category of "ditans," with a focus on lasmiditan, which is available for human use. MATERIALS AND METHODS: We consulted PubMed/MEDLINE, Web of Science, and www. CLINICALTRIALS: gov to find both original and review articles on the mechanism of action of 5-HT1F agonists in migraine, and for randomized, double-blind, placebo-controlled trials (RCTs) on the family of drugs called "ditans," with a focus on "lasmiditan," published in the time frame of 01-Jan-2010 to 31-Mar-2022. Only studies conducted in human subjects and published in English were included in this review. RESULTS: We retrieved four RCTs (named SAMURAI, SPARTAN, GLADIATOR, and CENTURION) and several studies that analyzed the efficacy and safety of lasmiditan. Lasmiditan at increasing doses showed significant improvement in pain and most other troublesome symptoms at 2 h. Adverse events were mild and mainly represented by dizziness, vertigo, drowsiness, and fatigue. No vasoconstrictive effects were described, suggesting the use of ditans as a safe option in chronic cardio- and cerebro-vascular disease. DISCUSSION: Lasmiditan could be a viable alternative to triptans, although further RCT studies and real-world evidence are needed to better understand its potential and possible adverse events in a larger population.

Tegaserod for Irritable Bowel Syndrome With Constipation in Women Younger Than 65 Years Without Cardiovascular Disease: Pooled Analyses of 4 Controlled Trials.

INTRODUCTION: Tegaserod was the first US Food and Drug Administration-approved drug for irritable bowel syndrome with constipation (IBS-C) in women and was recently reapproved for use. Recognizing that clinical trials were performed almost 20 years ago, we performed an integrated analysis on patient-reported outcomes relevant to current practice including previously unpublished data. METHODS: Data from 4 12-week, randomized, placebo-controlled trials evaluating tegaserod 6 mg b.i.d. in patients with IBS-C were pooled. We analyzed 2 groups: all women (overall population) and women younger than 65 years without a history of cardiovascular ischemic events (indicated population). The primary end point was subjective global assessment of IBS-C symptom relief. Responders rated themselves as "considerably" or "completely" relieved ≥50% of the time or at least "somewhat relieved" 100% of the time over the last 4 weeks. RESULTS: The overall and indicated populations included 2,939 (tegaserod [n = 1,478]; placebo [n = 1,461]) and 2,752 (tegaserod [n = 1,386]; placebo [n = 1,366]) participants, respectively. The pooled odds ratios (95% confidence interval) for clinical response during the last 4 weeks in the overall and indicated populations with tegaserod were 1.37 (1.18, 1.59; P < 0.001) and 1.38 (1.18, 1.61; P < 0.001). In the overall and indicated populations, clinical response rates for tegaserod during the last 4 weeks were 43.3% and 44.1% versus 35.9% and 36.5% with placebo (P < 0.001). Adverse events were similar between groups. No significant cardiovascular events related to tegaserod were observed in patients with ≤1 cardiac risk factor. DISCUSSION: Tegaserod 6 mg b.i.d. reduced IBS-C symptoms in overall and US Food and Drug Administration-indicated populations (women aged <65 years with no history of cardiovascular ischemic events).

TPN672: A Novel Serotonin-Dopamine Receptor Modulator for the Treatment of Schizophrenia.

TPN672 [7-(2-(4-(benzothiophen-4-yl) piperazin-1-yl)ethyl)quinolin-2(1H)-one maleate] is a novel antipsychotic candidate with high affinity for serotonin and dopamine receptors that is currently in clinical trial for the treatment of psychiatric disorders. In vitro binding study showed that TPN672 exhibited extremely high affinity for serotonin 1A receptor (5-HT1AR) (K i = 0.23 nM) and 5-HT2AR (K i = 2.58 nM) as well as moderate affinity for D3R (K i = 11.55 nM) and D2R (K i = 17.91 nM). In vitro functional assays demonstrated that TPN672 acted as a potent 5-HT1AR agonist, D2R/D3R partial agonist, and 5-HT2AR antagonist. TPN672 displayed robust antipsychotic efficacy in rodent models (e.g., blocking phencyclidine-induced hyperactivity), significantly better than aripiprazole, and ameliorated negative symptoms and cognitive deficits in the sociability test, dark avoidance response, Morris water maze test, and novel object recognition test. The results of electrophysiological experiments showed that TPN672 might inhibit the excitability of the glutamate system through activating 5-HT1AR in medial prefrontal cortex, thereby improving cognitive and negative symptoms. Moreover, the safety margin (the ratio of minimum catalepsy-inducing dose to minimum effective dose) of TPN672 was about 10-fold, which was superior to aripiprazole. In conclusion, TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having lower risk of extrapyramidal symptoms and hyperprolactinemia. SIGNIFICANCE STATEMENT: TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having a lower risk of extrapyramidal symptoms and hyperprolactinemia. A phase I clinical trial is now under way to test its tolerance, pharmacokinetics, and pharmacodynamic effects in human volunteers. Accordingly, the present results will have significant impact on the development of new antischizophrenia drugs.

Chemical update on the potential for serotonin 5-HT6 and 5-HT7 receptor agents in the treatment of Alzheimer's disease.

Despite the better understanding of the mechanisms underlying Alzheimer's Disease (AD) and launched clinical trials, no AD-modifying treatment based on a synthetic drug has been introduced for almost twenty years. The serotonin 5-HT6 and 5-HT7 receptors turned out to be promising biological targets for modulation of central nervous system dysfunctions including cognitive impairment. Within this paper, we evaluate the pharmacological potency of both, 5-HT6R and 5-HT7R, agents in search for novel AD treatment. An overview of chemical structures of the 5-HTRs ligands with simultaneous procognitive action which have undergone preclinical and clinical studies within the last 10 years has been performed.

Effectiveness of medication in cluster headache.

BACKGROUND: The aim of this work is to analyze the reports on cluster headache attacks collected online in the citizen science project CLUE with respect to the effectiveness of drugs taken during the attacks. The collection of data within the framework of citizen science projects opens up the possibility of investigating the effectiveness of acute medication on the basis of a large number of individual attacks instead of a simple survey of patients. METHODS: Data from 8369 cluster headache attacks, containing information about acute medication taken and the assessment of its effect, were collected from 133 participants using an online platform and a smartphone app. Chi-square tests were used to investigate whether the effect of the three recommended acute drugs differs when distinguishing between participants with chronic or episodic cluster headache. Furthermore, it was investigated whether there are differences between smokers and non-smokers in the assessment of the effect of the acute medication. RESULTS: Our participants rated the effectiveness of sumatriptan 6 mg s.c. as significantly better than oxygen and zolmitriptan nasal spray. Oxygen is considered to be significantly better in episodic versus chronic cluster headache, and sumatriptan is considered to be significantly better in chronic versus episodic cluster headache. Smokers rate the effect of oxygen as significantly better than non-smokers. CONCLUSIONS: Despite some methodological limitations, web-based data collection is able to support findings from clinical trials in a real world setting about effectiveness of acute cluster headache treatment in several situations.

Phase 2 randomized placebo-controlled study of lasmiditan for the acute treatment of migraine in Japanese patients.

OBJECTIVE: To evaluate the efficacy and safety of lasmiditan in Japanese adults with migraine. BACKGROUND: Global clinical studies have demonstrated the efficacy and safety of lasmiditan in the acute treatment of migraine. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, phase 2 study in Japan (NCT03962738), which enrolled adults with migraine with or without aura. Participants were randomized 7:3:7:6 to placebo, lasmiditan 50 mg, 100 mg, or 200 mg to be self-administered orally within 4 h of onset of a single moderate-to-severe migraine attack. Participants recorded their response to treatment prior to dosing and for 48 h postdose. The primary endpoint was headache pain freedom at 2 h postdose. RESULTS: Participants (N = 846) were randomized and treated (N = 691, safety; N = 682, modified intent-to-treat). At 2 h postdose, a significantly higher proportion of participants were headache pain-free in the lasmiditan 200 mg (40.8%, 73/179; odds ratio 3.46 [95% confidence interval 2.17 to 5.54]; p < 0.001; primary objective) and 100 mg groups (32.4%, 67/207; odds ratio 2.41 [1.51 to 3.83]; p < 0.001) compared with the placebo group (16.6%, 35/211), whereas the lasmiditan 50 mg group had a numerically higher proportion of participants headache pain-free (23.5%, 20/85; odds ratio 1.55 [0.83 to 2.87]; p = 0.167) compared with placebo. A statistically significant linear dose-response relationship for pain freedom was achieved at 2 h by a Cochran-Armitage trend test (p < 0.001). Lasmiditan treatment was also associated with headache pain relief, most bothersome symptom freedom, and improvement on disability and Patient Global Impression of Change outcomes. The majority of treatment-emergent adverse events were mild and of short duration, the most common of which were dizziness (39.4%; 188/477), somnolence (19.3%; 92/477), and malaise (10.5%; 50/477) in all lasmiditan groups, with no serious adverse events reported. CONCLUSIONS: Lasmiditan was well tolerated and effective for the acute treatment of Japanese patients with migraine, consistent with global phase 3 studies.

The American Headache Society Consensus Statement: Update on integrating new migraine treatments into clinical practice.

OBJECTIVE: To incorporate recent research findings, expert consensus, and patient perspectives into updated guidance on the use of new acute and preventive treatments for migraine in adults. BACKGROUND: The American Headache Society previously published a Consensus Statement on the use of newly introduced treatments for adults with migraine. This update, which is based on the expanded evidence base and emerging expert consensus concerning postapproval usage, provides practical recommendations in the absence of a formal guideline. METHODS: This update involved four steps: (1) review of data about the efficacy, safety, and clinical use of migraine treatments introduced since the previous Statement was published; (2) incorporation of these data into a proposed update; (3) review and commentary by the Board of Directors of the American Headache Society and patients and advocates associated with the American Migraine Foundation; (4) consideration of these collective insights and integration into an updated Consensus Statement. RESULTS: Since the last Consensus Statement, no evidence has emerged to alter the established principles of either acute or preventive treatment. Newly introduced acute treatments include two small-molecule calcitonin gene-related peptide (CGRP) receptor antagonists (ubrogepant, rimegepant); a serotonin (5-HT1F ) agonist (lasmiditan); a nonsteroidal anti-inflammatory drug (celecoxib oral solution); and a neuromodulatory device (remote electrical neuromodulation). New preventive treatments include an intravenous anti-CGRP ligand monoclonal antibody (eptinezumab). Several modalities, including neuromodulation (electrical trigeminal nerve stimulation, noninvasive vagus nerve stimulation, single-pulse transcranial magnetic stimulation) and biobehavioral therapy (cognitive behavioral therapy, biofeedback, relaxation therapies, mindfulness-based therapies, acceptance and commitment therapy) may be appropriate for either acute and/or preventive treatment; a neuromodulation device may be appropriate for acute migraine treatment only (remote electrical neuromodulation). CONCLUSIONS: The integration of new treatments into clinical practice should be informed by the potential for benefit relative to established therapies, as well as by the characteristics and preferences of individual patients.

Serotonin 1A agonist and cardiopulmonary improvements with whole-body exercise in acute, high-level spinal cord injury: a retrospective analysis.

PURPOSE: High-level spinal cord injury (SCI) can result in spinal and supraspinal respiratory control deficits leading to insufficient ventilatory responses to exercise and training-related adaptations. We hypothesized a serotonin agonist, known to improve respiratory function in animal models, would improve adaptations to whole-body functional electrical stimulation (FES) exercise training in patients with acute high-level SCI. METHODS: We identified 10 patients (< 2 years of injury with SCI from C4 to T3) in our program who had performed 6 months of FES-row training while on Buspirone (29 ± 17 mg/day) between 2012 and 2018. We also identified well-matched individuals who trained for six months but not on Buspirone (n = 11). A peak incremental FES-rowing exercise test and resting pulmonary function test had been performed before and after training. RESULTS: Those on Buspirone demonstrated greater increases in peak oxygen consumption (VO2peak: + 0.24 ± 0.23 vs. + 0.10 ± 0.13 L/min, p = 0.08) and peak ventilation (VEpeak: + 6.5 ± 8.1 vs. - 0.7 ± 6.9 L/min, p < 0.05) compared to control. In addition, changes in VO2peak and VEpeak were correlated across all patients (r = 0.63, p < 0.01), but most strongly in those on Buspirone (r = 0.85, p < 0.01). Furthermore, changes in respiratory function correlated with increased peak tidal volume in the Buspirone group (r > 0.66, p < 0.05). CONCLUSION: These results suggest Buspirone improves cardiorespiratory adaptations to FES-exercise training in individuals with acute, high-level SCI. The strong association between increases in ventilatory and aerobic capacities suggests improved respiratory function is a mechanism; however, controlled studies are needed to determine if this preliminary finding is reproducible.

Acute Treatments for Episodic Migraine in Adults: A Systematic Review and Meta-analysis.

Importance: Migraine is common and can be associated with significant morbidity, and several treatment options exist for acute therapy. Objective: To evaluate the benefits and harms associated with acute treatments for episodic migraine in adults. Data Sources: Multiple databases from database inception to February 24, 2021. Study Selection: Randomized clinical trials and systematic reviews that assessed effectiveness or harms of acute therapy for migraine attacks. Data Extraction and Synthesis: Independent reviewers selected studies and extracted data. Meta-analysis was performed with the DerSimonian-Laird random-effects model with Hartung-Knapp-Sidik-Jonkman variance correction or by using a fixed-effect model based on the Mantel-Haenszel method if the number of studies was small. Main Outcomes and Measures: The main outcomes included pain freedom, pain relief, sustained pain freedom, sustained pain relief, and adverse events. The strength of evidence (SOE) was graded with the Agency for Healthcare Research and Quality Methods Guide for Effectiveness and Comparative Effectiveness Reviews. Findings: Evidence on triptans and nonsteroidal anti-inflammatory drugs was summarized from 15 systematic reviews. For other interventions, 115 randomized clinical trials with 28 803 patients were included. Compared with placebo, triptans and nonsteroidal anti-inflammatory drugs used individually were significantly associated with reduced pain at 2 hours and 1 day (moderate to high SOE) and increased risk of mild and transient adverse events. Compared with placebo, calcitonin gene-related peptide receptor antagonists (low to high SOE), lasmiditan (5-HT1F receptor agonist; high SOE), dihydroergotamine (moderate to high SOE), ergotamine plus caffeine (moderate SOE), acetaminophen (moderate SOE), antiemetics (low SOE), butorphanol (low SOE), and tramadol in combination with acetaminophen (low SOE) were significantly associated with pain reduction and increase in mild adverse events. The findings for opioids were based on low or insufficient SOE. Several nonpharmacologic treatments were significantly associated with improved pain, including remote electrical neuromodulation (moderate SOE), transcranial magnetic stimulation (low SOE), external trigeminal nerve stimulation (low SOE), and noninvasive vagus nerve stimulation (moderate SOE). No significant difference in adverse events was found between nonpharmacologic treatments and sham. Conclusions and Relevance: There are several acute treatments for migraine, with varying strength of supporting evidence. Use of triptans, nonsteroidal anti-inflammatory drugs, acetaminophen, dihydroergotamine, calcitonin gene-related peptide antagonists, lasmiditan, and some nonpharmacologic treatments was associated with improved pain and function. The evidence for many other interventions, including opioids, was limited.

Chronic Lorcaserin Treatment Reverses the Nicotine Withdrawal-Induced Disruptions to Behavior and Maturation in Developing Neurons in the Hippocampus of Rats.

Preclinical data have shown that treatment with serotonin (5-HT)2C receptor agonists inhibits the behavioral effects of nicotine, including self-administration, reinstatement, and locomotor responses to nicotine. Since the data on the effects of 5-HT2C receptor agonism on nicotine withdrawal signs are limited, we aimed to investigate whether 5-HT2C receptor agonism alleviated the behavioral and neurobiochemical (hippocampal neurogenesis) consequences of nicotine withdrawal in Sprague-Dawley rats. Our data indicate that withdrawal from nicotine self-administration induced locomotor hyperactivity, lengthened immobility time (the forced swim test), induced 'drug-seeking' behavior and deficits in cognition-like behavior (the novel object recognition task). A two-week exposure to the 5-HT2C receptor agonist lorcaserin attenuated locomotor hyperactivity and induced recovery from depression-like behavior. Analyses of brain slices from nicotine-withdrawn animals revealed that lorcaserin treatment recovered the reduced number of doublecortin (DCX)-positive cells, but it did not affect the number of Ki-67- or 5-bromo-2'-deoxyuridine (BrdU)-positive cells or the maturation of proliferating neurons in drug-weaned rats. To summarize, we show that lorcaserin alleviated locomotor responses and depression-like state during nicotine withdrawal. We propose that the modulatory effect of lorcaserin on the 'affective' aspects of nicotine cessation may be linked to the positive changes caused by the compound in hippocampal neurogenesis during nicotine withdrawal.

Serotonergic-Muscarinic Interaction within the Prefrontal Cortex as a Novel Target to Reverse Schizophrenia-Related Cognitive Symptoms.

Recent studies revealed that the activation of serotonergic 5-HT1A and muscarinic M1, M4, or M5 receptors prevent MK-801-induced cognitive impairments in animal models. In the present study, the effectiveness of the simultaneous activation of 5-HT1A and muscarinic receptors at preventing MK-801-induced cognitive deficits in novel object recognition (NOR) or Y-maze tests was investigated. Activators of 5-HT1A (F15599), M1 (VU0357017), M4 (VU0152100), or M5 (VU0238429) receptors administered at top doses for seven days reversed MK-801-induced deficits in the NOR test, similar to the simultaneous administration of subeffective doses of F15599 (0.05 mg/kg) with VU0357017 (0.15 mg/kg), VU0152100 (0.05 mg/kg), or VU0238429 (1 mg/kg). The compounds did not prevent the MK-801-induced impairment when administered acutely. Their activity was less evident in the Y-maze. Pharmacokinetic studies revealed high brain penetration of F15599 (brain/plasma ratio 620%), which was detected in the frontal cortex (FC) up to 2 h after administration. Decreases in the brain penetration properties of the compounds were observed after acute administration of the combinations, which might have influenced behavioral responses. This negative effect on brain penetration was not observed when the compounds were administered repeatedly. Based on our results, prolonged administration of a 5-HT1A activator with muscarinic receptor ligands may be effective at reversing cognitive decline related to schizophrenia, and the FC may play a critical role in this interaction.

Modulation of Serotonin Receptors in Neurodevelopmental Disorders: Focus on 5-HT7 Receptor.

Since neurodevelopmental disorders (NDDs) influence more than 3% of children worldwide, there has been intense investigation to understand the etiology of disorders and develop treatments. Although there are drugs such as aripiprazole, risperidone, and lurasidone, these medications are not cures for the disorders and can only help people feel better or alleviate their symptoms. Thus, it is required to discover therapeutic targets in order to find the ultimate treatments of neurodevelopmental disorders. It is suggested that abnormal neuronal morphology in the neurodevelopment process is a main cause of NDDs, in which the serotonergic system is emerging as playing a crucial role. From this point of view, we noticed the correlation between serotonin receptor subtype 7 (5-HT7R) and NDDs including autism spectrum disorder (ASD), fragile X syndrome (FXS), and Rett syndrome (RTT). 5-HT7R modulators improved altered behaviors in animal models and also affected neuronal morphology via the 5-HT7R/G12 signaling pathway. Through the investigation of recent studies, it is suggested that 5-HT7R could be a potential therapeutic target for the treatment of NDDs.