Cocaine self-administration in the mouse: A low-cost, chronic catheter preparation

Intravenous drug self-administration is the most valid animal model of human addiction because it allows volitional titration of the drug in the blood based on an individual’s motivational state together with the pharmacokinetic properties of the drug. Here we describe a reliable low-cost mouse self-administration catheter assembly and protocol that that can be used to assess a variety of drugs of abuse with a variety of protocols. We describe a method for intravenous catheter fabrication that allows for efficient and long-lasting intravenous drug delivery. The intravenous catheters remained intact and patent for several weeks allowing us to establish stable maintenance of cocaine acquisition. This was followed by a dose response study in the same mice. For collaborators interested in premade catheters for research please make a request at www.neuro-cloud.net/nature-precedings/pomerenze

High fidelity optogenetic control of individual prefrontal cortical pyramidal neurons in vivo

Precise spatial and temporal manipulation of neural activity in specific genetically defined cell populations is now possible with the advent of optogenetics. The emerging field of optogenetics consists of a set of naturally-occurring and engineered light-sensitive membrane proteins that are able to activate (e.g., channelrhodopsin-2, ChR2) or silence (e.g., halorhodopsin, NpHR) neural activity. Here we demonstrate the technique and the feasibility of using novel adeno-associated viral (AAV) tools to activate (AAV-CaMKll{\alpha}-ChR2-eYFP) or silence (AAV-CaMKll{\alpha}-eNpHR3.0-eYFP) neural activity of rat prefrontal cortical prelimbic (PL) pyramidal neurons in vivo. In vivo single unit extracellular recording of ChR2-transduced pyramidal neurons showed that delivery of brief (10 ms) blue (473 nm) light-pulse trains up to 20 Hz via a custom fiber optic-coupled recording electrode (optrode) induced spiking with high fidelity at 20 Hz for the duration of recording (up to two hours in some cases). To silence spontaneously active neurons we transduced them with the NpHR construct and administered continuous green (532 nm) light to completely inhibit action potential activity for up to 10 seconds with 100% fidelity in most cases. These versatile photosensitive tools combined with optrode recording methods provide experimental control over activity of genetically defined neurons and can be used to investigate the functional relationship between neural activity and complex cognitive behavior.Comment: 4 pages, 4 figures F1000Research articl

Optogenetic control of genetically-targeted pyramidal neuron activity in prefrontal cortex

A salient feature of prefrontal cortex organization is the vast diversity of cell types that support the temporal integration of events required for sculpting future responses. A major obstacle in understanding the routing of information among prefrontal neuronal subtypes is the inability to manipulate the electrical activity of genetically defined cell types over behaviorally relevant timescales and activity patterns. To address these constraints, we present here a simple approach for selective activation of prefrontal excitatory neurons in both in vitro and in vivo preparations. Rat prelimbic pyramidal neurons were genetically targeted to express a light-­activated nonselective cation channel, channelrhodopsin-­2, or a light-­driven inward chloride pump, halorhodopsin, which enabled them to be rapidly and reversibly activated or inhibited by pulses of light. These light responsive tools provide a spatially and temporally precise means of studying how different cell types contribute to information processing in cortical circuits. Our customized optrodes and optical commutators for in vivo recording allow for efficient light delivery and recording and can be requested at www.neuro-­cloud.net/nature-precedings/baratta

Anomalous Temperature Dependence of the Electric Field Gradient at the Y Site in In₀.₁Y₀.₉Ba₂Cu₃O\u3csub\u3e9- δ\u3c/sub\u3e

Perturbed angular correlation (PAC) spectroscopy has been used to measure a well-defined static electric quadrupole interaction in a superconducting ceramic, In0.1Y0.9Ba2Cu3O9-δ. Perturbation functions, Fourier transforms, and the derived PAC parameters are given for data taken at temperatures ranging from 77 to 1070 K. Indirect evidence is presented for the occupation of the Y site by the 111In-111Cd PAC probe. The derived electric field gradients were found to increase linearly with temperature. This result suggests the presence of soft, anisotropic vibrations in the structure. Additional evidence is presented to indicate that O2--ion or O-vacancy transport may not occur in the Y coordination sphere

Use of an immunocapture device to detect cytokine release in discrete brain regions

Production of proinflammatory cytokines in the central nervous system is a key process in the neuroinflammatory response to trauma, infection, and neurodegenerative diseases (Kumar, 2019). These intercellular signaling molecules play multiple roles in the central nervous system immune response including the orchestration of the sickness response to innate immune perturbations in the brain (Dantzer et al., 2008). Brain innate immune cells such as microglia and other macrophages (perivascular, meningeal) are considered a significant source of cytokines (Ransohoff and Cardona, 2010) during neuroinflammatory conditions. Thus, quantification of cytokines in the central nervous system is essential to understanding the neuroimmune mechanisms underpinning neuroinflammatory conditions and to monitor the effects of treatment. However, quantification of brain cytokines has largely been limited to end-point measures of tissue protein levels of cytokines using techniques such as enzyme-linked immunosorbent assay (ELISA), western blot assay, or immunohistochemistry, which fail to discriminate between intracellular and extracellular levels of cytokines. In other words, an experimental change in total tissue levels of cytokines does not necessarily mean that the protein was secreted into the interstitial space within a brain region. Proinflammatory cytokine receptor antagonists as well as germ-line knockouts have been employed to block the behavioral, physiological, and neuroinflammatory response to stress (Goshen and Yirmiya, 2009) and immune challenge (McCusker and Kelley, 2013), which implicates, but does not directly demonstrate cytokine release in the brain. A further limitation of measuring cytokines in whole tissue is that measurements are restricted to a single time point post-mortem. This limitation necessitates using a between-subjects experimental design to conduct time course measurements of cytokines, which introduces error variance due to between-subject variability in biological responses. Notably, inflammatory cytokines such as interleukin (IL)-1&beta; have very short half-lives (Liu et al., 2021). Thus, methods that are limited to measuring single time points post-immune challenge lack the temporal resolution to capture the rapid kinetic changes in inflammatory cytokines. In this Perspective piece, we explore a recent technological advance that allowed us to serially quantify cytokines within the interstitial space of discrete brain regions of freely behaving rodents. This approach not only permits quantification of cytokine release into the extracellular space, but also provides increased spatial and temporal resolution of cytokine release in the brain under neuroinflammatory conditions. &nbsp;</p

Selective small molecule induced degradation of the BET bromodomain protein BRD4

The Bromo- and Extra-Terminal (BET) proteins BRD2, BRD3, and BRD4 play important roles in transcriptional regulation, epigenetics, and cancer and are the targets of pan-BET selective bromodomain inhibitor JQ1. However, the lack of intra-BET selectivity limits the scope of current inhibitors as probes for target validation and could lead to unwanted side effects or toxicity in a therapeutic setting. We designed Proteolysis Targeted Chimeras (PROTACs) that tether JQ1 to a ligand for the E3 ubiquitin ligase VHL, aimed at triggering the intracellular destruction of BET proteins. Compound MZ1 potently and rapidly induces reversible, long-lasting, and unexpectedly selective removal of BRD4 over BRD2 and BRD3. The activity of MZ1 is dependent on binding to VHL but is achieved at a sufficiently low concentration not to induce stabilization of HIF-1α. Gene expression profiles of selected cancer-related genes responsive to JQ1 reveal distinct and more limited transcriptional responses induced by MZ1, consistent with selective suppression of BRD4. Our discovery opens up new opportunities to elucidate the cellular phenotypes and therapeutic implications associated with selective targeting of BRD4

Anesthesia clinical workload estimated from electronic health record documentation vs billed relative value units

IMPORTANCE: Accurate measurements of clinical workload are needed to inform health care policy. Existing methods for measuring clinical workload rely on surveys or time-motion studies, which are labor-intensive to collect and subject to biases. OBJECTIVE: To compare anesthesia clinical workload estimated from electronic health record (EHR) audit log data vs billed relative value units. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study of anesthetic encounters occurring between August 26, 2019, and February 9, 2020, used data from 8 academic hospitals, community hospitals, and surgical centers across Missouri and Illinois. Clinicians who provided anesthetic services for at least 1 surgical encounter were included. Data were analyzed from January 2022 to January 2023. EXPOSURE: Anesthetic encounters associated with a surgical procedure were included. Encounters associated with labor analgesia and endoscopy were excluded. MAIN OUTCOMES AND MEASURES: For each encounter, EHR-derived clinical workload was estimated as the sum of all EHR actions recorded in the audit log by anesthesia clinicians who provided care. Billing-derived clinical workload was measured as the total number of units billed for the encounter. A linear mixed-effects model was used to estimate the relative contribution of patient complexity (American Society of Anesthesiology [ASA] physical status modifier), procedure complexity (ASA base unit value for the procedure), and anesthetic duration (time units) to EHR-derived and billing-derived workload. The resulting β coefficients were interpreted as the expected effect of a 1-unit change in each independent variable on the standardized workload outcome. The analysis plan was developed after the data were obtained. RESULTS: A total of 405 clinicians who provided anesthesia for 31 688 encounters were included in the study. A total of 8 288 132 audit log actions corresponding to 39 131 hours of EHR use were used to measure EHR-derived workload. The contributions of patient complexity, procedural complexity, and anesthesia duration to EHR-derived workload differed significantly from their contributions to billing-derived workload. The contribution of patient complexity toward EHR-derived workload (β = 0.162; 95% CI, 0.153-0.171) was more than 50% greater than its contribution toward billing-derived workload (β = 0.106; 95% CI, 0.097-0.116; P \u3c .001). In contrast, the contribution of procedure complexity toward EHR-derived workload (β = 0.033; 95% CI, 0.031-0.035) was approximately one-third its contribution toward billing-derived workload (β = 0.106; 95% CI, 0.104-0.108; P \u3c .001). CONCLUSIONS AND RELEVANCE: In this cross-sectional study of 8 hospitals, reimbursement for anesthesiology services overcompensated for procedural complexity and undercompensated for patient complexity. This method for measuring clinical workload could be used to improve reimbursement valuations for anesthesia and other specialties

From helplessness to controllability: toward a neuroscience of resilience

&ldquo;Learned helplessness&rdquo; refers to debilitating outcomes, such as passivity and increased fear, that follow an uncontrollable adverse event, but do not when that event is controllable. The original explanation argued that when events are uncontrollable the animal learns that outcomes are independent of its behavior, and that this is the active ingredient in producing the effects. Controllable adverse events, in contrast, fail to produce these outcomes because they lack the active uncontrollability element. Recent work on the neural basis of helplessness, however, takes the opposite view. Prolonged exposure to aversive stimulation per se produces the debilitation by potent activation of serotonergic neurons in the brainstem dorsal raphe nucleus. Debilitation is prevented with an instrumental controlling response, which activates prefrontal circuitry detecting control and subsequently blunting the dorsal raphe nucleus response. Furthermore, learning control alters the prefrontal response to future adverse events, thereby preventing debilitation and producing long-term resiliency. The general implications of these neuroscience findings may apply to psychological therapy and prevention, in particular by suggesting the importance of cognitions and control, rather than habits of control. &nbsp;</p