scholarly journals Cognitive deficits and increases in creatine precursors in a brain-specific knockout of the creatine transporter gene Slc6a8

2017 ◽  
Author(s):  
Kenea C. Udobi ◽  
Amanda N. Kokenge ◽  
Emily R. Hautman ◽  
Gabriela Ullo ◽  
Julie Coene ◽  
...  

AbstractCreatine transporter (CrT; SLC6A8) deficiency (CTD) is an X-linked disorder characterized by severe cognitive deficits, impairments in language, and an absence of brain creatine (Cr). In a previous study, we generated floxed Slc6a8 (Slc6a8flox) mice to create ubiquitous Slc6a8 knockout (Slc6a8-/y) mice. Slc6a8-/y mice lacked whole body Cr and exhibited cognitive deficits. While Slc6a8-/y mice have a similar biochemical phenotype to CTD patients, they also showed a reduction in size and reductions in swim speed that may have contributed to the observed deficits. To address this, we created brain-specific Slc6a8 knockout (bKO) mice by crossing Slc6a8Flox mice with Nestin-cre mice. bKO mice had reduced cerebral Cr levels while maintaining normal Cr levels in peripheral tissue. Interestingly, brain concentrations of the Cr synthesis precursor guanidinoacetic acid were increased in bKO mice. bKO mice had longer latencies and path lengths in the Morris water maze, without reductions in swim speed. In accordance with data from Slc6a8-/y mice, bKO mice showed deficits in novel object recognition as well as contextual and cued fear conditioning. bKO mice were also hyperactive, in contrast with data from the Slc6a8-/ymice. The results demonstrate that the loss of cerebral Cr is responsible for the learning and memory deficits seen in ubiquitous Slc6a8-/y mice.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olusegun G. Adebayo ◽  
Samuel A. Onasanwo ◽  
Abayomi M. Ajayi ◽  
Wadioni Aduema ◽  
Oyetola T. Oyebanjo ◽  
...  

Abstract Objectives Cnidoscolus aconitifolius have been investigated to have abundant phytochemicals. However, study on the effect of Cnidoscolus aconitifolius on neurobehavioral performance when supplemented with diet is lacking. The study is aimed at investigating the memory-enhancing effect of Cnidoscolus aconitifolius-supplemented diet (CAD) using Morris water maze and Novel object recognition test. Methods Ninety male Wistar rats (80–100 g) were fed with CAD (1, 2.5, 5 and 10%) continuously for a period of 4, 8 and 12 weeks respectively. Six animals per group were used for assessment of memory performance (Morris water maze [MWM] and Novel object recognition test [NORT]); afterwards the brain tissues were harvested for malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) estimation. Acetylcholinesterase (AChE) concentration was also determined. Hippocampal architectural change in the neuron was examined using hematoxylin and eosin (H&E) and cresyl fast violet (Nissl) stain. Results Higher percentage of CAD significantly (p<0.05) improve memory performance with time-dependent effects in rats fed with CAD on MMW and NORT. MDA significantly (p<0.05) reduce in 1 and 2.5% CAD groups at 4th weeks and in 2.5 and 5% CAD groups at 8th weeks while GSH concentration significantly (p<0.05) increase at 12th weeks in 2.5 and 10% CAD groups. However, CAT concentration significantly (p<0.05) increase in 2.5, and 5%, CAD groups, 1, 5, and 10% CAD groups and in 5, and 10% CAD groups at 4th, 8th and 12th weeks. AChE significantly (p<0.05) reduce at 4th and 12th weeks. Histological assessment reveals no neuronal and pyramidal degeneration (chromatolysis) at the hippocampal Cornu Ammonis 3 (CA3) region. Conclusions The results suggest that CAD boost memory performance in rats through positive modulation of oxidative stress, cholinergic system and degeneration of hippocampal neurons.


2020 ◽  
Vol 178 (2) ◽  
pp. 347-357
Author(s):  
Muhammad M Hossain ◽  
Abdelmadjid Belkadi ◽  
Sara Al-Haddad ◽  
Jason R Richardson

Abstract Deficits in learning and memory are often associated with disruption of hippocampal neurogenesis, which is regulated by numerous processes, including precursor cell proliferation, survival, migration, and differentiation to mature neurons. Recent studies demonstrate that adult born neurons in the dentate gyrus (DG) in the hippocampus can functionally integrate into the existing neuronal circuitry and contribute to hippocampal-dependent learning and memory. Here, we demonstrate that relatively short-term deltamethrin exposure (3 mg/kg every 3 days for 1 month) inhibits adult hippocampal neurogenesis and causes deficits in learning and memory in mice. Hippocampal-dependent cognitive functions were evaluated using 2 independent hippocampal-dependent behavioral tests, the novel object recognition task and Morris water maze. We found that deltamethrin-treated mice exhibited profound deficits in novel object recognition and learning and memory in water maze. Deltamethrin exposure significantly decreased bromodeoxyuridine (BrdU)-positive cells (39%) and Ki67+ cells (47%) in the DG of the hippocampus, indicating decreased cellular proliferation. In addition, deltamethrin-treated mice exhibited a 44% decrease in nestin-expressing neural progenitor cells and a 38% reduction in the expression of doublecortin (DCX), an early neuronal differentiation marker. Furthermore, deltamethrin-exposed mice exhibited a 25% reduction in total number of granule cells in the DG. These findings indicate that relatively short-term exposure to deltamethrin causes significant deficits in hippocampal neurogenesis that is associated with impaired learning and memory.


2019 ◽  
Vol 42 (5) ◽  
pp. 966-974 ◽  
Author(s):  
Kenea C. Udobi ◽  
Nicholas Delcimmuto ◽  
Amanda N. Kokenge ◽  
Zuhair I. Abdulla ◽  
Marla K. Perna ◽  
...  

2006 ◽  
Vol 553 (1-3) ◽  
pp. 109-119 ◽  
Author(s):  
Warren D. Hirst ◽  
Tania O. Stean ◽  
Derek C. Rogers ◽  
David Sunter ◽  
Pippa Pugh ◽  
...  

2016 ◽  
Vol 10 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Orla Moriarty ◽  
Claire L. Gorman ◽  
Fiona McGowan ◽  
Gemma K. Ford ◽  
Michelle Roche ◽  
...  

AbstractBackground and aimsAlthough neuropathic pain is known to negatively affect cognition, the neural mechanisms involved are poorly understood. Chronic pain is associated with changes in synaptic plasticity in the brain which may impact on cognitive functioning. The aim of this study was to model neuropathic pain in mid-aged rats using spinal nerve ligation (SNL). Following establishment of allodynia and hyperalgesia, behaviour was assessed in a battery of cognitive tests. Expression of the presynaptic protein, synaptophysin, and its colocalisation with the vesicular GABA and glutamate transporters (vGAT and vGLUT, respectively), was investigated in the medial prefrontal cortex (mPFC) and hippocampus.MethodsNine month old male Sprague Dawley rats underwent L5-L6 spinal nerve ligation or a sham procedure. Mechanical and cold allodynia and thermal hyperalgesia were assessed using von Frey, acetone and Hargreaves tests, respectively. Cognition was assessed in the novel-object recognition, air-puff passive avoidance and Morris water maze behavioural tasks. Immunohistochemistry was used to examine the expression of synaptophysin in the mPFC and CA1 region of the hippocampus and double labelling of synaptophysin and the vesicular transporters vGAT and vGlut was used to investigate the distribution of synaptophysin on GABAergic and glutamatergic neurons.ResultsSNL rats displayed impaired performance in the novel-object recognition task. Passive-avoidance responding, and spatial learning and memory in the Morris water maze, were unaffected by SNL surgery. However, in the water maze reversal task, pain-related impairments were evident during training and probe trials. SNL surgery was not associated with any differences in the expression of synaptophysin or its colocalisation with vGAT or vGLUT in the mPFC or the hippocampal CA1 region.ConclusionsThese results suggest that the SNL model of neuropathic pain is associated with deficits in recognition memory and cognitive flexibility, but these deficits are not associated with altered synaptophysin expression or distribution in the mPFC and CA1.ImplicationsCognitive complaints are common amongst chronic pain patients. Here we modelled cognitive impairment in a well-established animal model of neuropathic pain and investigated the neural mechanisms involved. A better understanding of this phenomenon is an important prerequisite for the development of improved treatment of patients affected.


2017 ◽  
Vol 04 (01) ◽  
pp. 036-045
Author(s):  
Gregory Smith ◽  
Nowrin Ahmed ◽  
Erin Arbuckle ◽  
Joaquin Lugo

Abstract Background One of the most devastating aspects of developmental epilepsy is the long-term impact on behavior. Children with epilepsy show a high co-morbidity with anxiety disorders and autism. Methods To examine whether early-life status epilepticus results in altered anxiety, repetitive behavior, social behavior, and learning and memory, we induced status epilepticus in male C57BL/6 mice on postnatal day (PD) 10. The mice received intraperitoneal injections of either kainic acid (2 mg/kg) or 0.9% normal saline. We also included a nontreated control group. Kainic acid induced status epilepticus for approximately 1.5 h. At PD60, the adult mice were then tested in a battery of behavioral tasks, including open field activity, elevated-plus maze, light-dark test, marble burying, social chamber, social partition, conditioned fear, novel object recognition, and Morris water maze. Results The early-life seizure group showed consistent increases in anxiety in the open field test (p < 0.05), elevated plus maze (p < 0.05), and light-dark task (p < 0.01). The seizure group showed significant (p < 0.01) impairment in the Morris water maze. There were no differences observed in marble burying, social partition, social chamber, novel object recognition, or delay fear conditioning tasks. Conclusions These results demonstrate that a single insult of status epilepticus during the neonatal period is sufficient to cause specific, long-term impairments in anxiety and spatial learning.


2021 ◽  
Author(s):  
◽  
Miriam Collins

<p>Previous research has demonstrated that ethanol produces differential effects on non-spatial or recognition memory and spatial memory; spatial memory deficits were consistently found to be more persistent than non-spatial memory deficits. Ethanol-produced deficits have also been found to be dependent on age at exposure, and exposure during adolescence produced more persistent deficits than when exposure was experienced by older subjects.  The current study investigated the effects of a “binge-like’ 5 day episode of ethanol exposure (1.0g/kg x 5) on performance in non-spatial and spatial forms of the novel object recognition (NOR) task. Subjects were exposed either during adolescence or following maturity. Tests were conducted 2 or 9 days following exposure. NOR was tested following inter-trial intervals of 1, 3, or 5 minutes. Data from mature rats could not be obtained or analysed due to procedural issues that precluded NOR measurement. Control rats failed to demonstrate NOR at any of the time intervals. Reasons for these negative findings are discussed.</p>


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