The effects of ventral tegmental administration of GABA(A), GABA(B), NMDA and AMPA receptor agonists on ventral pallidum self-stimulation

The ventral pallidum (VP) is a basal forebrain structure that is interconnected with motor and limbic structures and may be considered as an interface between motivational and effector neural signals. Results from a considerable number of studies suggest that this structure is critically involved in reward-related behavior. The VP shares reciprocal connections with other reward-implicated regions, such as the ventral tegmental area (VTA). This anatomy predicts that drug-induced neuronal alterations in the VTA could profoundly alter the function of the VP. Here, using the curve-shift intracranial self-stimulation method, we studied the effects of muscimol (GABA(A) agonist), baclofen (GABA(B) agonist), NMDA and AMPA, microinjected bilaterally into the VTA on the rewarding efficacy of VP self-stimulation. Central injections of the highest dose of muscimol (0.128 microg) resulted in significant elevations in VP self-stimulation thresholds, indicating a reduction in the rewarding efficacy of the stimulation. Elevations in VP self-stimulation thresholds were also evident after intrategmental injections of higher doses of baclofen (0.12, 0.48 microg). By contrast, intrategmental activation of NMDA and AMPA receptors did not affect reward thresholds. These findings suggest that GABAergic and glutamatergic transmission in the VTA activate different circuits that may mediate different functions. Thus, the VTA--VP projection activated by GABA modulates VP stimulation reward, while the projection activated by glutamate may be involved in reward-unrelated effects, rather than in the processing of reward. The decreased rewarding efficacy of VP self-stimulation following intrategmental injections of muscimol and baclofen may be due to GABAergic modulation of ventral tegmental dopaminergic and nondopaminergic neurons projecting to the VP.     

Pedicled myocutaneous and muscle flaps in the management of complicated cardiothoracic problems.

The purpose of this study was to review our experience with the management of patients with complicated cardiothoracic problems by the use of pedicled myocutaneous or muscle flaps, and discuss the various methods of reconstruction. Over the last 11 years, we have treated 54 patients with complicated cardiothoracic problems by reconstruction with pedicled myocutaneous or muscle flaps. The underlying causes were chest wall tumours (n = 13), radionecrosis of the chest wall (n = 12), deep or chronic sternal infections (n = 25), and bronchopleural fistulas (n = 4). The most commonly used muscles for reconstruction were pectoralis major and the rectus abdominis. Our results compare favourably with those reported elsewhere. We conclude that although the use of pedicled myocutaneous or muscle flaps is not free of complications, it is an effective and reliable method for the management of patients with complicated cardiothoracic problems.     

Primary cilia dynamics instruct tissue patterning and repair of corneal endothelium

Primary cilia are required for several signaling pathways, but their function in cellular morphogenesis is poorly understood. Here we show that emergence of an hexagonal cellular pattern during development of the corneal endothelium (CE), a monolayer of neural crest-derived cells that maintains corneal transparency, depends on a precise temporal control of assembly of primary cilia that subsequently disassemble in adult corneal endothelial cells (CECs). However, cilia reassembly occurs rapidly in response to an in vivo mechanical injury and precedes basal body polarization and cellular elongation in mature CECs neighboring the wound. In contrast, CE from hypomorphic IFT88 mutants (Tg737(orpk)) or following in vivo lentiviral-mediated IFT88 knockdown display dysfunctional cilia and show disorganized patterning, mislocalization of junctional markers, and accumulation of cytoplasmic acetylated tubulin. Our results indicate an active role of cilia in orchestrating coordinated morphogenesis of CECs during development and repair and define the murine CE as a powerful in vivo system to study ciliary-based cellular dynamics.     

From the protein to the graph: how to quantify immunohistochemistry staining of the skin using digital imaging

Quantitative immunohistochemistry is needed in order to reliably and accurately assess the expression of cellular proteins in tissue. Skin is a difficult tissue for automated image analysis due to its heterogeneous composition and its architecture. In the present study we used a psoriatic skin model to compare the expression of p53 and bcl-2 before and after treatment with anti-tumor necrosis factor-alpha using digital image analysis. Digital photomicrographs were acquired and analyzed with Scion image software in order to obtain the fraction of p53 and bcl-2 immunoreactive cells' area out of the total area investigated. Statistical analysis with ANOVA revealed a significant increase of p53 expression and a decrease of bcl-2 expression in all 3 epidermal layers during the course of therapy (p<0.001). The results were in line with the conventional histopathological evaluation using an arbitrary scale to grade the extent and intensity of the staining. So, the estimation of volume fraction of immunohistochemically labelled cells in skin tissue can be performed easily and rapidly using commonly available image analysis software and provides reproducible and unbiased numerical estimations of the amount of cell labelling.     

Label-free imaging of fibroblast membrane interfaces and protein signatures with vibrational infrared photothermal and phase signals: publisher’s note

This publisher’s notes amends the funding of [Biomed. Opt. Express 12, 303 (2021) 10.1364/BOE.411888 [PMC free article] [PubMed] [CrossRef] [Google Scholar]].

In [1], a grant number was added in the Funding section. The paper was corrected online on 26 July 2021.     

Obstructive sleep apnea and multiple facets of a neuroinflammatory response: a narrative review

BackgroundObstructive sleep apnea (OSA) is a chronic, highly prevalent, multi-system and sleep disorder, which may contribute to cognitive impairment and a variety of structural and neurophysiologic changes. The focus on OSA is warranted given its recognized links with major psychiatric and neurologic disorders, including Alzheimer’s disease. Some preliminary studies suggest a dual effect of the inflammatory response in OSA. Neuroinflammation may present with initial, potentially adaptive and homeostatic, and later, a more distinctly maladaptive, precipitating and perpetuating role.ObjectiveWe here propose and argue in favour of the inflammatory process in the brain as a likely binding mechanism behind at least some effects that OSA may have on the brain and its function. Several OSA-triggered molecular and cellular events, that could lead to a neurodegenerative cascade, are similarly discussed.MethodsThis perspective reviews the body of literature that investigates potential links between the inflammatory processes in the brain and the OSA. A special emphasis is placed on a potential role for neuroplastin, a novel transmembrane synaptic protein involved in the neuroplasticity and known to be differentially regulated in the OSA.ConclusionsThe intricate interplay between neuroinflammation and other mechanistic correlates of OSA add to the evidence that neuroinflammation may be a key target for future therapeutic strategies in a number of comorbid disorders. The future studies will need to answer whether it is sleep fragmentation (SF) or intermittent hypoxia (IH) which may drive any such neuroinflammation.     

Condition-independent sensitization of locomotor stimulation and mesocortical dopamine release following chronic nicotine treatment in the rat

Chronic nicotine (NIC) pretreatment has been shown to enhance NIC-induced locomotor stimulation, an effect that seems critically dependent on activation of brain dopamine (DA) systems. In the present study the effects of chronic, intermittent NIC treatment were examined in the rat to establish whether such behavioral sensitization is associated with specific, regional changes in brain dopaminergic activity. Male rats received daily injections in their home cage with either saline (SAL) or NIC (0.5 mg/kg, s.c.) for 12 days. Twenty-four hours later, the locomotor activity of the animals subjected to NIC challenge as well as the functional responsiveness of the mesolimbocortical dopaminergic system were assessed. To this end, microdialysis experiments were performed in awake animals, measuring extracellular concentrations of DA and its metabolites in the prefrontal cortex (PFC) and the nucleus accumbens (NAC). Extracellular single cell recordings from DA neurons in the ventral tegmental area (VTA) were also performed in anesthetized animals. NIC (0.5 mg/kg, s.c.) increased all measured parameters of locomotor activity, with the exception of rearing, in SAL-pretreated animals; these effects were substantially enhanced after pretreatment with NIC. Nicotine (0.5 mg/kg, s.c.) increased DA release in both the PFC and the NAC in SAL-treated animals. Nicotine pretreatment significantly enhanced this effect in the PFC, whereas it did not affect the response in the NAC. Low doses of intravenously administered NIC dose-dependently increased burst activity, starting at 12 μg/kg in the SAL pretreated animals and at 6 μg/kg in the NIC-pretreated animals, and also dose-dependently increased firing rate in SAL as well as NIC-pretreated animals, although starting at a higher dose level, i.e., 25 μg/kg. These results demonstrate that behavioral sensitization after chronic NIC treatment is accompanied by an enhanced dopamine release specifically within the PFC. This phenomenon may be highly significant for the dependence-producing effects of NIC, particularly in association with major psychiatric disorder, such as schizophrenia. © 1996 Wiley-Liss, Inc.