An acetylcholine alpha7 positive allosteric modulator rescues a schizophrenia-associated brain endophenotype in the 15q13.3 microdeletion, encompassing CHRNA7

The 15q13.3 microdeletion copy number variation is strongly associated with schizophrenia and epilepsy. The CHRNA7 gene, encoding nicotinic acetylcholine alpha 7 receptors (nAChA7Rs), is hypothesized to be one of the main genes in this deletion causing the neuropsychiatric phenotype. Here we used a recently developed 15q13.3 microdeletion mouse model to explore whether an established schizophrenia-associated connectivity phenotype is replicated in a murine model, and whether positive modulation of nAChA7 receptor might pharmacologically normalize the connectivity patterns. Resting-state fMRI data were acquired from male mice carrying a hemizygous 15q13.3 microdeletion (N=9) and from wild-type mice (N=9). To study the connectivity profile of 15q13.3 mice and test the effect of nAChA7 positive allosteric modulation, the 15q13.3 mice underwent two imaging sessions, one week apart, receiving a single intraperitoneal injection of either 15 mg/kg Lu AF58801 or saline. The control group comprised wild-type mice treated with saline. We performed seed-based functional connectivity analysis to delineate aberrant connectivity patterns associated with the deletion (15q13.3 mice (saline treatment) versus wild-type mice (saline treatment)) and their modulation by Lu AF58801 (15q13.3 mice (Lu AF58801 treatment) versus 15q13.3 mice (saline treatment)). Compared to wild-type mice, 15q13.3 mice evidenced a predominant hyperconnectivity pattern. The main effect of Lu AF58801 was a normalization of elevated functional connectivity between prefrontal and frontal, hippocampal, striatal, thalamic and auditory regions. The strongest effects were observed in brain regions expressing nAChA7Rs, namely hippocampus, cerebral cortex and thalamus. These effects may underlie the antiepileptic, pro-cognitive and auditory gating deficit-reversal effects of nAChA7R stimulation

Brexpiprazole II: Antipsychotic-Like and Procognitive Effects of a Novel Serotonin-Dopamine Activity Modulator

ABSTRACT Brexpiprazole piperazin-1-yl]butoxy}quinolin-2(1H)-one) is a novel serotonin-dopamine activity modulator with partial agonist activity at serotonin 1A (5-HT 1A ) and D 2/3 receptors, combined with potent antagonist effects on 5-HT 2A , a 1B -, and a 2C -adrenergic receptors. Brexpiprazole inhibited conditioned avoidance response (ED 50 = 6.0 mg/kg), apomorphine-or D-amphetamine-induced hyperactivity (ED 50 = 2.3 and 0.90, respectively), and apomorphine-induced stereotypy (ED 50 = 2.9) in rats at clinically relevant D 2 receptor occupancies. Brexpiprazole also potently inhibited apomorphine-induced eye blinking in monkeys. The results suggest that brexpiprazole has antipsychotic potential. Brexpiprazole induced catalepsy (ED 50 = 20) well above clinically relevant D 2 receptor occupancies, suggesting a low risk for extrapyramidal side effects. Subchronic treatment with phencyclidine (PCP) induced cognitive impairment in both novel object recognition (NOR) and attentional set-shifting (ID-ED) tests in rats. Brexpiprazole reversed the PCP-induced cognitive impairment in the NOR test at 1.0 and 3.0 mg/kg, and in the ID-ED test at 1.0 mg/kg. However, aripiprazole (10 mg/kg) was ineffective in both tests, despite achieving relevant D 2 occupancies. In the NOR test

Incidence, Clinical Presentation and Trends in Indication for Diagnostic Work-Up of Small Intestinal and Pancreatic Neuroendocrine Tumors

Background: The incidence of small intestinal (SI) and pancreatic neuroendocrine tumors (siNETs and pNETs) seems to have increased. The increased frequency of incidental findings might be a possible explanation. The study aimed to examine (1) changes in incidence and the stage at diagnosis (2010–2011 vs. 2019–2020), (2) changes in the initial indication for diagnostic workup and 3) the differences in stage between incidentally discovered vs. symptomatic disease during the entire study period. Methods: We performed a retrospective study, that includes consecutive siNET and pNET patients referred to the Copenhagen ENETS center of excellence in 2010–2011 and 2019–2020. Results: The annual incidence of siNET per 100,000 increased from 1.39 to 1.84, (p = 0.05). There was no change in the stage at diagnosis, and in both periods approximately 30% of patients were incidentally diagnosed (p = 0.62). Dissemination was found in 72/121 (60%) of symptomatic vs. 22/50 (44%) of incidentally discovered SI tumors in the entire cohort, (p = 0.06). The annual incidence of pNET increased from 0.42 to 1.39 per 100,000, (p < 0.001). The proportion of patients with disseminated disease decreased from 8/21 (38%) to 12/75 (16%), (p = 0.02) and the number of incidental findings increased from 4/21 (19%) to 43/75 (57%), (p = 0.002). More symptomatic patients had disseminated disease compared to patients with incidentally discovered tumors (15/49 (31%) vs. 5/47 (11%), (p = 0.01)). Conclusion: The incidence of siNET and pNETs increased over the past decade. For siNETs, the stage of disease and the distribution of symptomatic vs. incidentally discovered tumors were unchanged between the two periods. Patients with pNETs presented with more local and incidentally discovered tumors in the latter period. Patients with incidentally discovered siNETs had disseminated disease in 44% of the overall cases. The vast majority of incidentally found pNETs were localized

Pharmacological Effects of Lu AA21004A Novel Multimodal Compound for the Treatment of Major Depressive Disorder

1-[2-(2,4-Dimethylphenyl-sulfanyl)-phenyl]-piperazine (Lu AA21004) is a human (h) serotonin (5-HT) 3A receptor antagonist (K i = 3.7 nM), h5-HT 7 receptor antagonist (K i = 19 nM), h5-HT 1B receptor partial agonist (K i = 33 nM), h5-HT 1A receptor agonist (K i = 15 nM), and a human 5-HT transporter (SERT) inhibitor (K i = 1.6 nM) (J Med Chem 54:3206-3221, 2011). Here, we confirm that Lu AA21004 is a partial h5-HT 1B receptor agonist [EC 50 = 460 nM, intrinsic activity = 22%] using a whole-cell cAMP-based assay and demonstrate that Lu AA21004 is a rat (r) 5-HT 7 receptor antagonist (K i = 200 nM and IC 50 = 2080 nM). In vivo, Lu AA21004 occupies the r5-HT 1B receptor and rSERT (ED 50 = 3.2 and 0.4 mg/kg, respectively) after subcutaneous administration and is a 5-HT 3 receptor antagonist in the Bezold-Jarisch reflex assay (ED 50 = 0.11 mg/kg s.c.). In rat microdialysis experiments, Lu AA21004 (2.5-10.0 mg/kg s.c.) increased extracellular 5-HT, dopamine, and noradrenaline in the medial prefrontal cortex and ventral hippocampus. Lu AA21004 (5 mg/kg per day for 3 days; minipump subcutaneously), corresponding to 41% rSERT occupancy, significantly increased extracellular 5-HT in the ventral hippocampus. Furthermore, the 5-HT 3 receptor antagonist, ondansetron, potentiated the increase in extracellular levels of 5-HT induced by citalopram. Lu AA21004 has antidepressant- and anxiolytic- like effects in the rat forced swim (Flinders Sensitive Line) and social interaction and conditioned fear tests (minimal effective doses: 7.8, 2.0, and 3.9 mg/kg). In conclusion, Lu AA21004 mediates its pharmacological effects via two pharmacological modalities: SERT inhibition and 5-HT receptor modulation. In vivo, this results in enhanced release of several neurotransmitters and antidepressant- and anxiolytic-like profiles at doses for which targets in addition to the SERT are occupied. The multimodal activity profile of Lu AA21004 is distinct from that of current antidepressants