Probes for INS

Stressful life events induce abnormalities in emotional and cognitive behaviour. The endogenous opioid system plays an essential role in stress adaptation and coping strategies. In particular, the µ-opioid receptor (μR), one of the major opioid receptors, strongly influences memory processing in that alterations in μR signalling are associated with various neuropsychiatric disorders. However, it remains unclear whether μR signalling contributes to memory impairments induced by acute stress. Here, we utilized pharmacological methods and cell-type-selective/non-cell-type-selective μR depletion approaches combined with behavioural tests, biochemical analyses, and in vitro electrophysiological recordings to investigate the role of hippocampal μR signalling in memory-retrieval impairment induced by acute elevated platform (EP) stress in mice. Biochemical and molecular analyses revealed that hippocampal μRs were significantly activated during acute stress. Blockage of hippocampal μRs, non-selective deletion of μRs or selective deletion of μRs on GABAergic neurons (μRGABA) reversed EP-stress-induced impairment of memory retrieval, with no effect on the elevation of serum corticosterone after stress. Electrophysiological results demonstrated that stress depressed hippocampal GABAergic synaptic transmission to CA1 pyramidal neurons, thereby leading to excitation/inhibition (E/I) imbalance in a μRGABA-dependent manner. Pharmaceutically enhancing hippocampal GABAAreceptor-mediated inhibitory currents in stressed mice restored their memory retrieval, whereas inhibiting those currents in the unstressed mice mimicked the stress-induced impairment of memory retrieval. Our findings reveal a novel pathway in which endogenous opioids recruited by acute stress predominantly activate μRGABA to depress GABAergic inhibitory effects on CA1 pyramidal neurons, which subsequently alters the E/I balance in the hippocampus and results in impairment of memory retrieval.

There is an urgent need for better treatments for chronic pain, which affects more than 1 billion people worldwide. Antisense oligonucleotides (ASOs) have proven successful in treating children with spinal muscular atrophy, a severe infantile neurological disorder, and several compounds based on ASOs are currently being tested in clinical trials for various neurological disorders. Here we characterize the pharmacodynamic activity of ASOs in spinal cord and dorsal root ganglia (DRG), key tissues for pain signaling. We demonstrate that the activity of ASOs lasts up to 2 months after a single intrathecal bolus dose in the spinal cord. Interestingly, comparison of subcutaneous, central intracerebroventricular and intrathecal administration shows DRGs are targetable by systemic and central delivery of ASOs, while target reduction in the spinal cord is achieved only after direct central delivery. Upon detailed characterization of ASO activity in individual cell populations in DRG, we observe robust target suppression in all neuronal populations thereby establishing that ASOs are effective in the cell populations involved in pain propagation. Furthermore, we confirm that ASOs are selective and do not modulate basal pain sensation. We also demonstrate that ASOs targeting the sodium channel Nav1.7 induce sustained analgesia up to 4 weeks. Taken together, our findings support the idea that ASOs possess the required pharmacodynamic properties, along with a long duration of action beneficial for treating pain.

Social recognition, the ability to recognize individuals that were previously encountered, requires complex integration of sensory inputs with previous experience. Here, we use a variety of approaches to discern how oxytocin sensitive neurons in the prefrontal cortex (PFC) exert descending control over a circuit mediating social recognition in mice. Using male mice with Cre-recombinase directed to the oxytocin receptor gene (Oxtr), we revealed that the Oxtr is expressed on glutamatergic neurons in the PFC, optogenetic stimulation of which, elicited activation of neurons residing in several mesolimbic brain structures. Optogenetic stimulation of axons in the basolateral amygdala (BLA) arising from Oxtr-expressing neurons in the PFC eliminated the ability to distinguish novel from familiar conspecifics, but remarkably, distinguishing between novel and familiar objects was unaffected. These results suggest that an oxytocin sensitive PFC to BLA circuit is required for social recognition. The implication is that impaired social memory may manifest from dysregulation of this circuit.SIGNIFICANCE STATEMENTUsing mice we demonstrate that optogenetic activation of the neurons in the prefrontal cortex (PFC) that express the oxytocin receptor gene (Oxtr) impairs the ability to distinguish between novel and familiar conspecifics but the ability to distinguish between novel and familiar objects remains intact. Subjects with Autism Spectrum Disorders (ASD) have difficulty identifying a person based on remembering facial features; however, ASD and typical subjects perform similarly when remembering objects. In subjects with ASD, viewing the same face increases neural activity in the PFC, which may be analogous to the optogenetic excitation of Oxtr-expressing neurons in the PFC that impairs social recognition in mice. The implication is that over-activation of Oxtr-expressing neurons in the PFC may contribute to ASD symptomology.

For decades, histopathology with routine hematoxylin and eosin staining has been and remains the gold standard for reaching a morphologic diagnosis in tissue samples from humans and veterinary species. However, within the past decade, there has been exponential growth in advanced techniques for in situ tissue biomarker imaging that bridge the divide between anatomic and molecular pathology. It is now possible to simultaneously observe localization and expression magnitude of multiple protein, nucleic acid, and molecular targets in tissue sections and apply machine learning to synthesize vast, image-derived datasets. As these technologies become more sophisticated and widely available, a team-science approach involving subspecialists with medical, engineering, and physics backgrounds is critical to upholding quality and validity in studies generating these data. The purpose of this manuscript is to detail the scientific premise, tools and training, quality control, and data collection and analysis considerations needed for the most prominent advanced imaging technologies currently applied in tissue sections: immunofluorescence, in situ hybridization, laser capture microdissection, matrix-assisted laser desorption ionization imaging mass spectrometry, and spectroscopic/optical methods. We conclude with a brief overview of future directions for ex vivo and in vivo imaging techniques.