DNA-PAINT adaptors make for efficient multiplexing.

Multiplexed super-resolution imaging offers a route to spatial proteomics; however, time-efficient mapping of many protein species has been challenging. Two recent works in Cell highlight SUM-PAINT and FLASH-PAINT, methods that leverage adaptor DNA strand design to combine advances in multiplexing with increases in speed of label exchange. These advances permit unbiased omics-style analyses to advance biological insights from super-resolution images.

Trifunctional Linkers Enable Improved Visualization of Actin by Expansion Microscopy.

Expansion microscopy (ExM) revolutionized the field of super-resolution microscopy by allowing for subdiffraction resolution fluorescence imaging on standard fluorescence microscopes. However, it has been found that it is hard to visualize actin filaments efficiently using ExM. To improve actin imaging, multifunctional molecules have been designed with moderate success.

Insulin-like growth factor 1 supplementation supports motor coordination and affects myelination in preterm pigs.

Introduction: Preterm infants have increased risk of impaired neurodevelopment to which reduced systemic levels of insulin-like growth factor 1 (IGF-1) in the weeks after birth may play a role. Hence, we hypothesized that postnatal IGF-1 supplementation would improve brain development in preterm pigs, used as a model for preterm infants.

Methods: Preterm pigs delivered by cesarean section received recombinant human IGF-1/IGF binding protein-3 complex (rhIGF-1/rhIGFBP-3, 2.

Within-Mice Comparison of Microdialysis and Fiber Photometry-Recorded Dopamine Biosensor during Amphetamine Response.

A fundamental concept in neuroscience is the transmission of information between neurons via neurotransmitters, -modulators, and -peptides. For the past decades, the gold standard for measuring neurochemicals in awake animals has been microdialysis (MD). The emergence of genetically encoded fluorescence-based biosensors, as well as optical techniques such as fiber photometry (FP), has introduced technologically distinct means of measuring neurotransmission.

Behavioral encoding across timescales by region-specific dopamine dynamics.

The dorsal (DS) and ventral striatum (VS) receive dopaminergic projections that control motor functions and reward-related behavior. It remains poorly understood how dopamine release dynamics across different temporal scales in these regions are coupled to behavioral outcomes. Here, we employ the dopamine sensor dLight1.

Nanoscopic dopamine transporter distribution and conformation are inversely regulated by excitatory drive and D2 autoreceptor activity.

The nanoscopic organization and regulation of individual molecular components in presynaptic varicosities of neurons releasing modulatory volume neurotransmitters like dopamine (DA) remain largely elusive. Here we show, by application of several super-resolution microscopy techniques to cultured neurons and mouse striatal slices, that the DA transporter (DAT), a key protein in varicosities of dopaminergic neurons, exists in the membrane in dynamic equilibrium between an inward-facing nanodomain-localized and outward-facing unclustered configuration. The balance between these configurations is inversely regulated by excitatory drive and DA D2 autoreceptor activation in a manner dependent on Ca influx via N-type voltage-gated Ca channels.

Modeling the early stages of Alzheimer's disease by administering intracerebroventricular injections of human native Aβ oligomers to rats.

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease characterized by the accumulation of aggregated amyloid beta (Aβ) and hyperphosphorylated tau along with a slow decline in cognitive functions. Unlike advanced AD, the initial steps of AD pathophysiology have been poorly investigated, partially due to limited availability of animal models focused on the early, plaque-free stages of the disease. The aim of this study was to evaluate the early behavioral, anatomical and molecular alterations in wild-type rats following intracerebroventricular injections of human Aβ oligomers (AβOs).

A density-based enrichment measure for assessing colocalization in single-molecule localization microscopy data.

Dual-color single-molecule localization microscopy (SMLM) provides unprecedented possibilities for detailed studies of colocalization of different molecular species in a cell. However, the informational richness of the data is not fully exploited by current analysis tools that often reduce colocalization to a single value. Here, we describe a tool specifically designed for determination of co-localization in both 2D and 3D from SMLM data.

Cholestasis alters brain lipid and bile acid composition and compromises motor function in neonatal piglets.

Infants with neonatal cholestasis are prone to neurodevelopmental deficits, however, the underlying pathogenesis is unclear. Lipid malabsorption and accumulation of potentially neurotoxic molecules in the blood such as bile acids are important yet relatively unexplored pathways. Here, we developed a translational piglet model to understand how the molecular bile acid and lipid composition of the brain is affected by this disease and relates to motor function.

Dissociating reward sensitivity and negative urgency effects on impulsivity in the five-choice serial reaction time task.

Negative urgency describes the tendency for rash and impulsive behaviour during negative emotional states and has been linked to a number of psychiatric disorders. However, there has been limited research on negative urgency as an explanatory mechanism for impulsivity in experimental animals. Such research has important implications for elucidating the neurobiology of negative urgency and thereby the development of future therapeutic interventions.

Coding variants identified in patients with diabetes alter PICK1 BAR domain function in insulin granule biogenesis.

Bin/amphiphysin/Rvs (BAR) domains are positively charged crescent-shaped modules that mediate curvature of negatively charged lipid membranes during remodeling processes. The BAR domain proteins PICK1, ICA69, and the arfaptins have recently been demonstrated to coordinate the budding and formation of immature secretory granules (ISGs) at the trans-Golgi network. Here, we identify 4 coding variants in the PICK1 gene from a whole-exome screening of Danish patients with diabetes that each involve a change in positively charged residues in the PICK1 BAR domain.

Disruption of the PDZ domain-binding motif of the dopamine transporter uniquely alters nanoscale distribution, dopamine homeostasis, and reward motivation.

The dopamine (DA) transporter (DAT) is part of a presynaptic multiprotein network involving interactions with scaffold proteins via its C-terminal PDZ domain-binding sequence. Using a mouse model expressing DAT with mutated PDZ-binding sequence (DAT-AAA), we previously demonstrated the importance of this binding sequence for striatal expression of DAT. Here, we show by application of direct stochastic reconstruction microscopy not only that the striatal level of transporter is reduced in DAT-AAA mice but also that the nanoscale distribution of this transporter is altered with a higher propensity of DAT-AAA to localize to irregular nanodomains in dopaminergic terminals.

Identifying dominant-negative actions of a dopamine transporter variant in patients with parkinsonism and neuropsychiatric disease.

Dysfunctional dopaminergic neurotransmission is central to movement disorders and mental diseases. The dopamine transporter (DAT) regulates extracellular dopamine levels, but the genetic and mechanistic link between DAT function and dopamine-related pathologies is not clear. Particularly, the pathophysiological significance of monoallelic missense mutations in DAT is unknown.

Rab2 drives axonal transport of dense core vesicles and lysosomal organelles.

Fast axonal transport of neuropeptide-containing dense core vesicles (DCVs), endolysosomal organelles, and presynaptic components is critical for maintaining neuronal functionality. How the transport of DCVs is orchestrated remains an important unresolved question. The small GTPase Rab2 mediates DCV biogenesis and endosome-lysosome fusion.

Novel Fluorescent Ligands Enable Single-Molecule Localization Microscopy of the Dopamine Transporter.

The dopamine transporter (DAT) is critical for spatiotemporal control of dopaminergic neurotransmission and is the target for therapeutic agents, including ADHD medications, and abused substances, such as cocaine. Here, we develop new fluorescently labeled ligands that bind DAT with high affinity and enable single-molecule detection of the transporter. The cocaine analogue MFZ2-12 () was conjugated to novel rhodamine-based Janelia Fluorophores (JF and JF).

An Amphipathic Helix Directs Cellular Membrane Curvature Sensing and Function of the BAR Domain Protein PICK1.

BAR domains are dimeric protein modules that sense, induce, and stabilize lipid membrane curvature. Here, we show that membrane curvature sensing (MCS) directs cellular localization and function of the BAR domain protein PICK1. In PICK1, and the homologous proteins ICA69 and arfaptin2, we identify an amphipathic helix N-terminal to the BAR domain that mediates MCS.

Super-resolution microscopy reveals functional organization of dopamine transporters into cholesterol and neuronal activity-dependent nanodomains.

Dopamine regulates reward, cognition, and locomotor functions. By mediating rapid reuptake of extracellular dopamine, the dopamine transporter is critical for spatiotemporal control of dopaminergic neurotransmission. Here, we use super-resolution imaging to show that the dopamine transporter is dynamically sequestrated into cholesterol-dependent nanodomains in the plasma membrane of presynaptic varicosities and neuronal projections of dopaminergic neurons.

Disruption of hippocampal synaptic transmission and long-term potentiation by psychoactive synthetic cannabinoid 'Spice' compounds: comparison with Δ -tetrahydrocannabinol.

There has been a marked increase in the availability of synthetic drugs designed to mimic the effects of marijuana. These cannabimimetic drugs, sold illicitly as 'Spice' and related products, are associated with serious medical complications in some users. In vitro studies suggest that synthetic cannabinoids in these preparations are potent agonists at central cannabinoid CB1 receptors (CB1Rs), but few investigations have delineated their cellular effects, particularly in comparison with the psychoactive component of marijuana, Δ -tetrahydrocannabinol (Δ -THC).

Wheel running exercise attenuates vulnerability to self-administer nicotine in rats.

Background: Preventing or postponing tobacco use initiation could greatly reduce the number of tobacco-related deaths. While evidence suggests that exercise is a promising treatment for tobacco addiction, it is not clear whether exercise could prevent initial vulnerability to tobacco use. Thus, using an animal model, we examined whether exercise attenuates vulnerability to the use and reinforcing effects of nicotine, the primary addictive chemical in tobacco.

Acute and chronic administration of a low-dose combination of topiramate and ondansetron reduces ethanol's reinforcing effects in male alcohol preferring (P) rats.

Topiramate (a GABA/glutamate modulator) and ondansetron (a serotonin-3 antagonist) have shown promise as treatments for alcohol use disorders (AUDs), although efficacy is modest/variable for both medications. We recently showed in animal models of consumption and relapse that acute treatment with a combination of these medications was more efficacious than either alone. To determine whether the mechanism for its beneficial effects is through modulation of ethanol's reinforcing effects, we measured the effect of this combination in male alcohol preferring (P) rats (N = 22) responding for ethanol under a progressive-ratio (PR) schedule.

Diminished role of dopamine D1-receptor signaling with the development of an addicted phenotype in rats.

Background: Although considerable evidence implicates dopamine D1-receptor signaling in the nucleus accumbens in motivation for cocaine during early stages of addiction, less is known with regard to its role after the development of addiction. Here, we examined its role in the development of an addicted phenotype in intact male and female rats, and in female rats that were either resistant or vulnerable to developing this phenotype.

Methods: Intact males, females, and ovariectomized (OVX) females with and without estradiol (vulnerable, OVX+E; resistant, OVX+Veh) were given either short access (ShA) (three fixed-ratio 1 sessions, maximum of 20 infusions) or 24-hour extended access (ExA) to cocaine for 10 days (4 trials/hour).