Dynamic endocannabinoid-mediated neuromodulation of retinal circadian circuitry.

Circadian rhythms are biological rhythms that originate from the "master circadian clock," called the suprachiasmatic nucleus (SCN). SCN orchestrates the circadian rhythms using light as a chief zeitgeber, enabling humans to synchronize their daily physio-behavioral activities with the Earth's light-dark cycle. However, chronic/ irregular photic disturbances from the retina via the retinohypothalamic tract (RHT) can disrupt the amplitude and the expression of clock genes, such as the period circadian clock 2, causing circadian rhythm disruption (CRd) and associated neuropathologies. The present review discusses neuromodulation across the RHT originating from retinal photic inputs and modulation offered by endocannabinoids as a function of mitigation of the CRd and associated neuro-dysfunction. Literature indicates that cannabinoid agonists alleviate the SCN's ability to get entrained to light by modulating the activity of its chief neurotransmitter, i.e., γ-aminobutyric acid, thus preventing light-induced disruption of activity rhythms in laboratory animals. In the retina, endocannabinoid signaling modulates the overall gain of the retinal ganglion cells by regulating the membrane currents (Ca2+, K+, and Cl- channels) and glutamatergic neurotransmission of photoreceptors and bipolar cells. Additionally, endocannabinoids signalling also regulate the high-voltage-activated Ca2+ channels to mitigate the retinal ganglion cells and intrinsically photosensitive retinal ganglion cells-mediated glutamate release in the SCN, thus regulating the RHT-mediated light stimulation of SCN neurons to prevent excitotoxicity. As per the literature, cannabinoid receptors 1 and 2 are becoming newer targets in drug discovery paradigms, and the involvement of endocannabinoids in light-induced CRd through the RHT may possibly mitigate severe neuropathologies.

Ethical considerations in public engagement: developing tools for assessing the boundaries of research and involvement.

Public engagement with research (PEwR) has become increasingly integral to research practices. This paper explores the process and outcomes of a collaborative effort to address the ethical implications of PEwR activities and develop tools to navigate them within the context of a University Medical School. The activities this paper reflects on aimed to establish boundaries between research data collection and PEwR activities, support colleagues in identifying the ethical considerations relevant to their planned activities, and build confidence and capacity among staff to conduct PEwR projects. The development process involved the creation of a taxonomy outlining key terms used in PEwR work, a self-assessment tool to evaluate the need for formal ethical review, and a code of conduct for ethical PEwR. These tools were refined through iterative discussions and feedback from stakeholders, resulting in practical guidance for researchers navigating the ethical complexities of PEwR. Additionally, reflective prompts were developed to guide researchers in planning and conducting engagement activities, addressing a crucial aspect often overlooked in formal ethical review processes. The paper reflects on the broader regulatory landscape and the limitations of existing approval and governance processes, and prompts critical reflection on the compatibility of formal approval processes with the ethos of PEwR. Overall, the paper offers insights and practical guidance for researchers and institutions grappling with ethical considerations in PEwR, contributing to the ongoing conversation surrounding responsible research practices.

Loss of GPR75 protects against non-alcoholic fatty liver disease and body fat accumulation.

Approximately 1 in 4 people worldwide have non-alcoholic fatty liver disease (NAFLD); however, there are currently no medications to treat this condition. This study investigated the role of adiposity-associated orphan G protein-coupled receptor 75 (GPR75) in liver lipid accumulation. We profiled Gpr75 expression and report that it is most abundant in the brain. Next, we generated the first single-cell-level analysis of Gpr75 and identified a subpopulation co-expressed with key appetite-regulating hypothalamic neurons. CRISPR-Cas9-deleted Gpr75 mice fed a palatable western diet high in fat adjusted caloric intake to remain in energy balance, thereby preventing NAFLD. Consistent with mouse results, analysis of whole-exome sequencing data from 428,719 individuals (UK Biobank) revealed that variants in GPR75 are associated with a reduced likelihood of hepatic steatosis. Here, we provide a significant advance in understanding of the expression and function of GPR75, demonstrating that it is a promising pharmaceutical target for NAFLD treatment.