First-in-man study to investigate safety, pharmacokinetics and exploratory pharmacodynamics of HTL0018318, a novel M -receptor partial agonist for the treatment of dementias.

Aims: HTL0018318 is a selective M receptor partial agonist currently under development for the symptomatic treatment of cognitive and behavioural symptoms in Alzheimer's disease and other dementias. We investigated safety, tolerability, pharmacokinetics and exploratory pharmacodynamics (PD) of HTL0018318 following single ascending doses.

Methods: This randomized, double-blind, placebo-controlled study in 40 healthy younger adult and 57 healthy elderly subjects, investigated oral doses of 1-35 mg HTL0018318.

New approaches in psychiatric drug development.

Numerous novel neuroscience-based drug targets have been identified in recent years. However, it remains unclear how these targets relate to the expression of symptoms in central nervous system (CNS) disorders in general and psychiatric disorders in particular. To discuss this issue, a New Frontiers Meetings of European College of Neuropsychopharmacology (ECNP) was organized to address the challenges in translational neuroscience research that are impeding the effective development of new treatments.

Human Dosimetry of the -Methyl-d-Aspartate Receptor Ligand C-GMOM.

The methylguanidine derivative C-GMOM (C-labeled -(2-chloro-3-thiomethylphenyl)-'-(3-methoxyphenyl)-'-methylguanidine) has been used successfully to quantify -methyl-d-aspartate (NMDA) receptor binding in humans. The purpose of the present study was to estimate the C-GMOM radiation dose in healthy humans. After C-GMOM injection, 3 female and 2 male subjects underwent 10 consecutive whole-body PET scans in approximately 77 min.

In vivo (R)-[(11)C]PK11195 PET imaging of 18kDa translocator protein in recent onset psychosis.

Evidence is accumulating that immune dysfunction is involved in the pathophysiology of schizophrenia. It has been hypothesized that microglia activation is present in patients with schizophrenia. Various in vivo and post-mortem studies have investigated this hypothesis, but as yet with inconclusive results.

Quantification of the novel N-methyl-d-aspartate receptor ligand [11C]GMOM in man.

[(11)C]GMOM (carbon-11 labeled N-(2-chloro-5-thiomethylphenyl)-N'-(3-[(11)C]methoxy-phenyl)-N'-methylguanidine) is a PET ligand that binds to the N-methyl-d-aspartate receptor with high specificity and affinity. The purpose of this first in human study was to evaluate kinetics of [(11)C]GMOM in the healthy human brain and to identify the optimal pharmacokinetic model for quantifying these kinetics, both before and after a pharmacological dose of S-ketamine. Dynamic 90 min [(11)C]GMOM PET scans were obtained from 10 subjects.

Assessing brain immune activation in psychiatric disorders: clinical and preclinical PET imaging studies of the 18-kDa translocator protein.

Accumulating evidence from different lines of research suggests an involvement of the immune system in the pathophysiology of several psychiatric disorders. During recent years, a series of positron emission tomography (PET) studies have been published using radioligands for the translocator protein (TSPO) to study microglia activation in schizophrenia, bipolar I disorder, major depression, autism spectrum disorder, and drug abuse. The results have been somewhat conflicting, which could be due to differences both in patient sample characteristics and in PET methods.

Dopaminergic activity in Tourette syndrome and obsessive-compulsive disorder.

Tourette syndrome (TS) and obsessive-compulsive disorder (OCD) both are neuropsychiatric disorders associated with abnormalities in dopamine neurotransmission. Aims of this study were to quantify striatal D2/3 receptor availability in TS and OCD, and to examine dopamine release and symptom severity changes in both disorders following amphetamine challenge. Changes in [(11)C]raclopride binding potential (BP(ND)) were assessed using positron emission tomography before and after administration of d-amphetamine (0.

Microglial activation in Alzheimer's disease: an (R)-[¹¹C]PK11195 positron emission tomography study.

Unlabelled: Inflammatory mechanisms, like microglial activation, could be involved in the pathogenesis of Alzheimer's disease (AD). (R)-[(11)C]PK11195 (1-(2-chlorophenyl)-N-methyl-N-1(1-methylpropyl)-3-isoquinolinecarboxamide), a positron emission tomography (PET) ligand, can be used to quantify microglial activation in vivo. The purpose of this study was to assess whether increased (R)-[(11)C]PK11195 binding is present in AD and mild cognitive impairment (MCI), currently also known as "prodromal AD.

Microglial activation in healthy aging.

Healthy brain aging is characterized by neuronal loss and decline of cognitive function. Neuronal loss is closely associated with microglial activation and postmortem studies have indeed suggested that activated microglia may be present in the aging brain. Microglial activation can be quantified in vivo using (R)-[(11)C]PK11195 and positron emission tomography.