The effects of microinjections of adrenergic receptors agonists and antagonists into the median raphe nucleus (MR) on behavior and serotonin (5HT) metabolism was examined in rats. Administration of adrenergic alpha 1 and alpha 2 receptor agonists (noradrenaline, phenylephrine, clonidine) produced behavioral excitation in the open field test and a tendency to decrease the forebrain 5-hydroxyindolo-acetic acid (5HIAA) concentration. Opposite effects were seen after microinjection of adrenergic alpha receptor antagonists (phenoxybenzamine, phentolamine but not yohimbine). A significant negative correlation was found between the effects on locomotor activity and 5HIAA levels in these rats. No effect was present after injection of beta receptor agonist salbutamol or antagonist propranolol. It is suggested that noradrenaline released from noradrenergic terminals in the MR tonically inhibits the activity of 5HT neurons thus producing symptoms of 5HT deficiency and that this action of noradrenaline is probably limited to the effects on alpha 1 but not alpha 2 nor beta adrenoceptors in this brain region.
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http://dx.doi.org/10.1016/0091-3057(83)90306-4 | DOI Listing |
Alzheimers Dement
December 2024
Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Background: Calcineurin, a protein involved in functions such as synaptic plasticity and neuronal survival, plays an important role in the pathophysiology of Alzheimer's disease. This study, randomized, investigated the effects of FK506 (FK), a calcineurin inhibitor, on the behavioral, histological, and biochemical alterations observed in models of neurotoxicity induced by NMDA or Aβ and in a transgenic model for AD, in addition to the organotypic culture model stimulated with NMDA.
Methods: This study involved models for AD to experiment injecting NMDA or Aβ1-42 into the hippocampus of male C57Bl/6 mice aged 8-12 weeks to induce a neurotoxicity model, treating double-transgenic APP/PS1 mice, expressing both mouse/human APP and mutant human PS1, with chronic FK506 for AD, in which, to enable NMDA or Aβ1-42 microinjections, another experiment including a stereotaxic surgery was performed on the C57Bl/6 mice.
CNS Neurosci Ther
January 2025
Department of Pharmacy, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
Aims: Stroke is a major public health concern leading to high rates of death and disability worldwide, unfortunately with no effective treatment available for stroke recovery during the repair phase.
Methods: Photothrombotic stroke was induced in mice. Adeno-associated viruses (AAV) were microinjected into the peri-infarct cortex immediately after photothrombotic stroke.
J Neurophysiol
December 2024
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA.
The dorsolateral prefrontal cortex (DLPFC) plays a crucial role in primate cognition, integrating multimodal information to generate top-down signals for cognitive control. During cognitive tasks, the DLPFC displays activity patterns of exceptional complexity and duration not observed in other cortical areas or species. These activity patterns are likely associated with the unique physiological and morphological properties of primate DLPFC pyramidal neurons (PNs).
View Article and Find Full Text PDFSci Rep
December 2024
School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.
Microtextured microneedles are tiny needle-like structures with micron-scale microtextures, and the drugs stored in the microtextures can be released after entering the skin to achieve the effect of precise drug delivery. In this study, the skin substitution model of Ogden's hyperelastic model and the microneedle array and microtexture models with different geometrical parameters were selected to simulate and analyse the flow of the microtexture microneedle arrays penetrating the skin by the finite-element method, and the length of the microneedles was determined to be 200 μm, the width 160 μm, and the value of the gaps was determined to be 420 μm. A four-pronged cone was chosen as the shape of microneedles, and a rectangle was chosen as the shape of the drug-carrying microneedle.
View Article and Find Full Text PDFSheng Wu Gong Cheng Xue Bao
December 2024
State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China.
The effects of host factors ADP-ribosylation factor 4 (ARF4) and ADP-ribosylation factor 5 (ARF5) upon Zika virus (ZIKV) infection were characterized by construction of gene knockout mice via CRISPR-Cas9. Firstly, and genes were modified by the CRISPR-Cas9 system and then microinjected into the fertilized eggs of C57BL/6JGpt mice. Fertilized eggs were transplanted to obtain or knockout (ARF4KO or ARF5KO) mice, and / double knockout mice were achieved by the mating between ARF4KO and ARF5KO mice (ARF4KO/ARF5KO).
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