scholarly journals A Novel Assay Allowing Drug Self-Administration, Extinction, and Reinstatement Testing in Head-Restrained Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Kelsey M. Vollmer ◽  
Elizabeth M. Doncheck ◽  
Roger I. Grant ◽  
Kion T. Winston ◽  
Elizaveta V. Romanova ◽  
...  
Keyword(s):  
Oral Delivery ◽  
New Technologies ◽  
Multiphoton Microscopy ◽  
Abuse Liability ◽  
Behavioral Repertoire ◽  
Self Administration ◽  
Multiphoton Imaging ◽  
Head Restraint ◽  
Behavioral Paradigm ◽  
Neural Underpinnings

Multiphoton microscopy is one of several new technologies providing unprecedented insight into the activity dynamics and function of neural circuits. Unfortunately, some of these technologies require experimentation in head-restrained animals, limiting the behavioral repertoire that can be integrated and studied. This issue is especially evident in drug addiction research, as no laboratories have coupled multiphoton microscopy with simultaneous intravenous drug self-administration, a behavioral paradigm that has predictive validity for treatment outcomes and abuse liability. Here, we describe a new experimental assay wherein head-restrained mice will press an active lever, but not inactive lever, for intravenous delivery of heroin or cocaine. Similar to freely moving animals, we find that lever pressing is suppressed through daily extinction training and subsequently reinstated through the presentation of relapse-provoking triggers (drug-associative cues, the drug itself, and stressors). Finally, we show that head-restrained mice will show similar patterns of behavior for oral delivery of a sucrose reward, a common control used for drug self-administration experiments. Overall, these data demonstrate the feasibility of combining drug self-administration experiments with technologies that require head-restraint, such as multiphoton imaging. The assay described could be replicated by interested labs with readily available materials to aid in identifying the neural underpinnings of substance use disorder.

scholarly journals Drug self-administration in head-restrained mice for simultaneous multiphoton imaging

2020 ◽  
Author(s):  
Kelsey M. Vollmer ◽  
Elizabeth M. Doncheck ◽  
Roger I. Grant ◽  
Kion T. Winston ◽  
Elizaveta V. Romanova ◽  
...  
Keyword(s):  
Drug Addiction ◽  
New Technologies ◽  
Drugs Of Abuse ◽  
Neural Circuit ◽  
Multiphoton Microscopy ◽  
Behavioral Repertoire ◽  
Self Administration ◽  
Multiphoton Imaging ◽  
Longitudinal Tracking ◽  
Insight Into

ABSTRACTMultiphoton microscopy is one of several new technologies providing unprecedented insight into the activity dynamics and function of neural circuits. Unfortunately, many of these technologies require experimentation in head-restrained animals, greatly limiting the behavioral repertoire that can be studied with each approach. This issue is especially evident in drug addiction research, as no laboratories have coupled multiphoton microscopy with simultaneous intravenous drug self-administration, the gold standard of behavioral paradigms for investigating the neural mechanisms of drug addiction. Such experiments would be transformative for addiction research as one could measure or perturb an array of behavior and drug-related adaptations in precisely defined neural circuit elements over time, including but not limited to dendritic spine plasticity, neurotransmitter release, and neuronal activity. Here, we describe a new experimental assay wherein mice self-administer drugs of abuse while head-restrained, allowing for simultaneous multiphoton imaging. We demonstrate that this approach enables longitudinal tracking of activity in single neurons from the onset of drug use to relapse. The assay can be easily replicated by interested labs for relatively little cost with readily available materials and can provide unprecedented insight into the neural underpinnings of substance use disorder.

Evaluation of abuse liability using self-administration, extinction and reinstatement in the monkey using cocaine and fentanyl

2012 ◽  
Vol 66 (2) ◽  
pp. 167
Author(s):  
David A. Hygate ◽  
Rex Manguiat ◽  
Wei Jie Wong ◽  
Sonali Medakkar ◽  
Daniel M. Hutcheson
Keyword(s):  
Abuse Liability ◽  
Self Administration

scholarly journals Hindlimb heating increases vascular access of large molecules to murine tibial growth plates measured by in vivo multiphoton imaging

2014 ◽  
Vol 116 (4) ◽  
pp. 425-438 ◽  
Author(s):  
Maria A. Serrat ◽  
Morgan L. Efaw ◽  
Rebecca M. Williams
Keyword(s):  
Growth Plate ◽  
Vascular Access ◽  
Multiphoton Microscopy ◽  
Molecular Transport ◽  
Vessel Diameter ◽  
Cartilage Growth ◽  
Multiphoton Imaging ◽  
Growth Plates ◽  
Large Molecules

Advances in understanding the molecular regulation of longitudinal growth have led to development of novel drug therapies for growth plate disorders. Despite progress, a major unmet challenge is delivering therapeutic agents to avascular-cartilage plates. Dense extracellular matrix and lack of penetrating blood vessels create a semipermeable “barrier,” which hinders molecular transport at the vascular-cartilage interface. To overcome this obstacle, we used a hindlimb heating model to manipulate bone circulation in 5-wk-old female mice ( n = 22). Temperatures represented a physiological range of normal human knee joints. We used in vivo multiphoton microscopy to quantify temperature-enhanced delivery of large molecules into tibial growth plates. We tested the hypothesis that increasing hindlimb temperature from 22°C to 34°C increases vascular access of large systemic molecules, modeled using 10, 40, and 70 kDa dextrans that approximate sizes of physiological regulators. Vascular access was quantified by vessel diameter, velocity, and dextran leakage from subperichondrial plexus vessels and accumulation in growth plate cartilage. Growth plate entry of 10 kDa dextrans increased >150% at 34°C. Entry of 40 and 70 kDa dextrans increased <50%, suggesting a size-dependent temperature enhancement. Total dextran levels in the plexus increased at 34°C, but relative leakage out of vessels was not temperature dependent. Blood velocity and vessel diameter increased 118% and 31%, respectively, at 34°C. These results demonstrate that heat enhances vascular carrying capacity and bioavailability of large molecules around growth plates, suggesting that temperature could be a noninvasive strategy for modulating delivery of therapeutics to impaired growth plates of children.

scholarly journals Multiphoton imaging reveals axial differences in metabolic autofluorescence signals along the kidney proximal tubule

2018 ◽  
Vol 315 (6) ◽  
pp. F1613-F1625 ◽  
Author(s):  
Milica Bugarski ◽  
Joana Raquel Martins ◽  
Dominik Haenni ◽  
Andrew M. Hall
Keyword(s):  
Mitochondrial Function ◽  
Redox State ◽  
Kidney Diseases ◽  
Multiphoton Microscopy ◽  
Kidney Tissue ◽  
Kidney Cortex ◽  
Label Free ◽  
Multiphoton Imaging ◽  
Imaging Approach ◽  
Lactate And Pyruvate

Kidney proximal tubules (PTs) are densely packed with mitochondria, and defects in mitochondrial function are implicated in many kidney diseases. However, little is known about intrinsic mitochondrial function within PT cells. Here, using intravital multiphoton microscopy and live slices of mouse kidney cortex, we show that autofluorescence signals provide important functional readouts of redox state and substrate metabolism and that there are striking axial differences in signals along the PT. Mitochondrial NAD(P)H intensity was similar in both PT segment (S)1 and S2 and was sensitive to changes in respiratory chain (RC) redox state, whereas cytosolic NAD(P)H intensity was significantly higher in S2. Mitochondrial NAD(P)H increased in response to lactate and butyrate but decreased in response to glutamine and glutamate. Cytosolic NAD(P)H was sensitive to lactate and pyruvate and decreased dramatically in S2 in response to inhibition of glucose metabolism. Mitochondrial flavoprotein (FP) intensity was markedly higher in S2 than in S1 but was insensitive to changes in RC redox state. Mitochondrial FP signal increased in response to palmitate but decreased in response to glutamine and glutamate. Fluorescence lifetime decays were similar in both S1 and S2, suggesting that intensity differences are explained by differences in abundance of the same molecular species. Expression levels of known fluorescent mitochondrial FPs were higher in S2 than S1. In summary, substantial metabolic information can be obtained in kidney tissue using a label-free live imaging approach, and our findings suggest that metabolism is tailored to the specialized functions of S1 and S2 PT segments.

scholarly journals An animal-actuated rotational head-fixation system for 2-photon imaging during 2-d navigation

2018 ◽  
Author(s):  
Jakob Voigts ◽  
Mark T. Harnett
Keyword(s):  
Large Scale ◽  
Pyramidal Neurons ◽  
Imaging Techniques ◽  
Retrosplenial Cortex ◽  
Body Motion ◽  
Behavioral Repertoire ◽  
Head Restraint ◽  
Head Fixation ◽  
Photon Imaging ◽  
Fixation System

AbstractUnderstanding how the biology of the brain gives rise to the computations that drive behavior requires high fidelity, large scale, and subcellular measurements of neural activity. 2-photon microscopy is the primary tool that satisfies these requirements, particularly for measurements during behavior. However, this technique requires rigid head-fixation, constraining the behavioral repertoire of experimental subjects. Increasingly, complex task paradigms are being used to investigate the neural substrates of complex behaviors, including navigation of complex environments, resolving uncertainty between multiple outcomes, integrating unreliable information over time, and/or building internal models of the world. In rodents, planning and decision making processes are often expressed via head and body motion. This produces a significant limitation for head-fixed two-photon imaging. We therefore developed a system that overcomes a major problem of head-fixation: the lack of rotational vestibular input. The system measures rotational strain exerted by mice on the head restraint, which consequently drives a motor, rotating the constraint system and dissipating the strain. This permits mice to rotate their heads in the azimuthal plane with negligible inertia and friction. This stable rotating head-fixation system allows mice to explore physical or virtual 2-D environments. To demonstrate the performance of our system, we conducted 2-photon GCaMP6f imaging in somas and dendrites of pyramidal neurons in mouse retrosplenial cortex. We show that the subcellular resolution of the system’s 2-photon imaging is comparable to that of conventional head-fixed experiments. Additionally, this system allows the attachment of heavy instrumentation to the animal, making it possible to extend the approach to large-scale electrophysiology experiments in the future. Our method enables the use of state-of-the-art imaging techniques while animals perform more complex and naturalistic behaviors than currently possible, with broad potential applications in systems neuroscience.

scholarly journals In vivo multiphoton fluorescence imaging with polymer dots

2017 ◽  
Author(s):  
Ahmed M. Hassan ◽  
Xu Wu ◽  
Jeremy W. Jarrett ◽  
Shihan Xu ◽  
David R. Miller ◽  
...  
Keyword(s):  
Multiphoton Microscopy ◽  
Multiphoton Imaging ◽  
Two Photon ◽  
Photon Excitation ◽  
Deep Imaging ◽  
Polymer Dots ◽  
Versatile Tool ◽  
Cortical Imaging ◽  
Semiconducting Polymer Dots

AbstractDeep in vivo imaging of vasculature requires small, bright, and photostable fluorophores suitable for multiphoton microscopy (MPM). Although semiconducting polymer dots (pdots) are an emerging class of highly fluorescent contrast agents with favorable advantages for the next generation of in vivo imaging, their use for deep multiphoton imaging has never before been demonstrated. Here we characterize the multiphoton properties of three pdot variants (CNPPV, PFBT, and PFPV) and demonstrate deep imaging of cortical microvasculature in C57 mice. Specifically, we measure the two-versus three-photon power dependence of these pdots and observe a clear three-photon excitation signature at wavelengths longer than 1300 nm, and a transition from two-photon to three-photon excitation within a 1060 – 1300 nm excitation range. Furthermore, we show that pdots enable in vivo two-photon imaging of cerebrovascular architecture in mice up to 850 μm beneath the pial surface using 800 nm excitation. In contrast with traditional multiphoton probes, we also demonstrate that the broad multiphoton absorption spectrum of pdots permits imaging at longer wavelengths (λex = 1,060 and 1225 nm). These wavelengths approach an ideal biological imaging wavelength near 1,300 nm and confer compatibility with a high-power ytterbium-fiber laser and a high pulse energy optical parametric amplifier, resulting in substantial improvements in signal-to-background ratio (>3.5-fold) and greater cortical imaging depths of 900 μm and 1300 μm. Ultimately, pdots are a versatile tool for MPM due to their extraordinary brightness and broad absorption, which will undoubtedly unlock the ability to interrogate deep structures in vivo.

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