scholarly journals Multimodal Neuroimaging Study of Visual Plasticity in Schizophrenia

2021 ◽  
Vol 12 ◽  
Author(s):  
S. Andrea Wijtenburg ◽  
Jeffrey West ◽  
Stephanie A. Korenic ◽  
Franchesca Kuhney ◽  
Frank E. Gaston ◽  
...  
Keyword(s):  
Visual Stimulation ◽  
Visual Learning ◽  
Long Term Potentiation ◽  
Control Group ◽  
Resonance Spectroscopy ◽  
Visual Plasticity ◽  
Area V2 ◽  
Term Potentiation ◽  
Visual Cortical Area ◽  
Visual Cortical

Schizophrenia is a severe mental illness with visual learning and memory deficits, and reduced long term potentiation (LTP) may underlie these impairments. Recent human fMRI and EEG studies have assessed visual plasticity that was induced with high frequency visual stimulation, which is thought to mimic an LTP-like phenomenon. This study investigated the differences in visual plasticity in participants with schizophrenia and healthy controls. An fMRI visual plasticity paradigm was implemented, and proton magnetic resonance spectroscopy data were acquired to determine whether baseline resting levels of glutamatergic and GABA metabolites were related to visual plasticity response. Adults with schizophrenia did not demonstrate visual plasticity after family-wise error correction; whereas, the healthy control group did. There was a significant regional difference in visual plasticity in the left visual cortical area V2 when assessing group differences, and baseline GABA levels were associated with this specific ROI in the SZ group only. Overall, this study suggests that visual plasticity is altered in schizophrenia and related to basal GABA levels.

scholarly journals Exposure to 3′Sialyllactose-Poor Milk during Lactation Impairs Cognitive Capabilities in Adulthood

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4191
Author(s):  
Edoardo Pisa ◽  
Alberto Martire ◽  
Valentina Chiodi ◽  
Alice Traversa ◽  
Viviana Caputo ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Selective Reduction ◽  
Long Term Potentiation ◽  
Control Group ◽  
Preclinical Model ◽  
Knock Out ◽  
Cognitive Domains ◽  
Memory And Attention ◽  
Term Potentiation ◽  
Regulatory Functions

Breast milk exerts pivotal regulatory functions early in development whereby it contributes to the maturation of brain and associated cognitive functions. However, the specific components of maternal milk mediating this process have remained elusive. Sialylated human milk oligosaccharides (HMOs) represent likely candidates since they constitute the principal neonatal dietary source of sialic acid, which is crucial for brain development and neuronal patterning. We hypothesize that the selective neonatal lactational deprivation of a specific sialylated HMOs, sialyl(alpha2,3)lactose (3′SL), may impair cognitive capabilities (attention, cognitive flexibility, and memory) in adulthood in a preclinical model. To operationalize this hypothesis, we cross-fostered wild-type (WT) mouse pups to B6.129-St3gal4tm1.1Jxm/J dams, knock-out (KO) for the gene synthesizing 3′SL, thereby providing milk with approximately 80% 3′SL content reduction. We thus exposed lactating WT pups to a selective reduction of 3′SL and investigated multiple cognitive domains (including memory and attention) in adulthood. Furthermore, to account for the underlying electrophysiological correlates, we investigated hippocampal long-term potentiation (LTP). Neonatal access to 3′SL-poor milk resulted in decreased attention, spatial and working memory, and altered LTP compared to the control group. These results support the hypothesis that early-life dietary sialylated HMOs exert a long-lasting role in the development of cognitive functions.

Nicotine-induced impairments of spatial cognition and long-term potentiation in adolescent male rats

2013 ◽  
Vol 33 (2) ◽  
pp. 203-213 ◽  
Author(s):  
G Han ◽  
L An ◽  
B Yang ◽  
L Si ◽  
T Zhang
Keyword(s):  
Young Adult ◽  
Learning And Memory ◽  
Long Term Potentiation ◽  
Male Rats ◽  
Adolescent Male ◽  
Control Group ◽  
Adult Offspring ◽  
Behavioral Impairment ◽  
Term Potentiation

The aim of the present study was to investigate whether cognitive behavioral impairment, induced by nicotine in offspring rats, was associated with the alteration of hippocampal short-term potentiation (STP) and long-term potentiation (LTP) and to discuss the potential underlying mechanism. Young adult offspring rats were randomly divided into three groups. The groups include: control group (CC), nicotine group 1 (NC), in which their mothers received nicotine from gestational day 3 (GD3) to GD18, and nicotine group 2 (CN), in which young adult offspring rats received nicotine from postnatal day 42 (PD42) to PD56. Morris water maze (MWM) test was performed and then field excitatory postsynaptic potentials elicited by the stimulation of perforant pathway were recorded in the hippocampal dentate gyrus region. The results of the MWM test showed that learning and memory were impaired by either prenatal or postnatal nicotine exposure. In addition, it was found that there was no statistical difference of the MWM data between both nicotine treatments. In the electrophysiological test, LTP and STP were significantly inhibited in both NC and CN groups in comparison with the CC group. Notably, STP in CN group was also lower than that in the NC group. These findings suggested that both prenatal and postnatal exposure to nicotine induced learning and memory deficits, while the potential mechanism might be different from each other due to their dissimilar impairments of synaptic plasticity.

The nitric oxide synthase inhibitor, N-monomethyl-L-arginine blocks induction of a long-term potentiation-like phenomenon in rat medial frontal cortical neurons in vitro

1993 ◽  
Vol 70 (3) ◽  
pp. 1255-1259 ◽  
Author(s):  
A. V. Nowicky ◽  
L. J. Bindman
Keyword(s):  
Nitric Oxide ◽  
Cortical Neurons ◽  
Long Term Potentiation ◽  
Control Group ◽  
Term Potentiation ◽  
The Mean ◽  
Synthase Inhibitor ◽  
Stimulation Of

1. Nitric oxide has been implicated in the production of long-term depression (LTD) in the cerebellum and in the production of long-term potentiation (LTP) and LTD in the hippocampus. We now provide evidence of its involvement in the induction of long-term synaptic potentiation in in vitro slices in the cerebral cortex of the rat. 2. Intracellular recordings were made from layer V neurons in the medial frontal cortex, and excitatory synaptic potentials (EPSPs) were evoked by electrical stimulation of layers II/III. Tetanic stimulation of this pathway may induce LTD or LTP or no change at these synapses. First we established experimental conditions under which a long lasting potentiation could be induced with a high incidence (> 60%), namely perfusion of slices with 1 microM bicuculline methiodide, second the use of increased shock duration in the tetanic conditioning stimuli, third and most important the addition of QX-314 to the microelectrode to reduce potassium conductances. Because the potentiation of the mean EPSP slope was significantly greater than the control at 40-min postconditioning, but was declining throughout this period, we refer to it for brevity as LTP, but strictly class it as an LTP-like phenomenon. 3. The nitric oxide (NO) synthase inhibitor interfered with the production of LTP. In the control group of neurons (n = 13) the mean depolarizing slope of the EPSP at 30-min post-conditioning was 142.7 +/- 2% (mean +/- SE) of the prestimulation control.(ABSTRACT TRUNCATED AT 250 WORDS)

Presynaptic Activity and Ca2+ Entry Are Required for the Maintenance of NMDA Receptor–Independent LTP at Visual Cortical Excitatory Synapses

2004 ◽  
Vol 92 (2) ◽  
pp. 1077-1087 ◽  
Author(s):  
Hong Nian Liu ◽  
Tohru Kurotani ◽  
Ming Ren ◽  
Kazumasa Yamada ◽  
Yumiko Yoshimura ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Long Term Potentiation ◽  
Inhibitory Synapses ◽  
Excitatory Synapses ◽  
Test Stimulation ◽  
Term Potentiation ◽  
Pharmacological Blockade ◽  
Visual Cortical ◽  
P Type

We have shown that some neural activity is required for the maintenance of long-term potentiation (LTP) at visual cortical inhibitory synapses. We tested whether this was also the case in N-methyl-d-aspartate (NMDA) receptor–independent LTP of excitatory connections in layer 2/3 cells of developing rat visual cortex. This LTP occurred after 2-Hz stimulation was applied for 15 min and always persisted for several hours while test stimulation was continued at 0.1 Hz. When test stimulation was stopped for 1 h after LTP induction, only one-third of the LTP instances disappeared, but most did disappear under a pharmacological suppression of spontaneous firing, indicating that LTP maintenance requires either evoked or spontaneous activities. LTP was totally abolished by a temporary blockade of action potentials with lidocaine or the removal of extracellular Ca2+ after LTP induction, but it persisted under a voltage clamp of postsynaptic cells or after a temporary blockade of postsynaptic activity with the glutamate receptor antagonist kynurenate, suggesting that LTP maintenance requires presynaptic, but not postsynaptic, firing and Ca2+ entry. More than one-half of the LTP instances were abolished after a pharmacological blockade of P-type Ca2+ channels, whereas it persisted after either L-type or Ni2+-sensitive Ca2+ channel blockades. These results show that the maintenance of NMDA receptor–independent excitatory LTP requires presynaptic firing and Ca2+ channel activation as inhibitory LTP, although the necessary level of firing and Ca2+ entry seems lower for the former than the latter and the Ca2+ channel types involved are only partly the same.

Neuroprotective and long term potentiation improving effects of vitamin E in juvenile hypothyroid rats

2020 ◽  
Vol 90 (1-2) ◽  
pp. 156-168 ◽  
Author(s):  
Yousef Baghcheghi ◽  
Somaieh Mansouri ◽  
Farimah Beheshti ◽  
Mohammad Naser Shafei ◽  
Hossien Salmani ◽  
...  
Keyword(s):  
Vitamin E ◽  
Neuronal Apoptosis ◽  
Long Term Potentiation ◽  
Control Group ◽  
High Frequency Stimulation ◽  
Protective Effects ◽  
Term Potentiation ◽  
Frequency Stimulation ◽  
Collateral Pathway

Abstract. Protective effects of vitamin E (Vit E) on long term potentiation (LTP) impairment, neuronal apoptosis and increase of nitric oxide (NO) metabolites in the hippocampus of juvenile rats were examined. The rats were grouped (n=13) as: (1) control; (2) hypothyroid (Hypo) and (3) Hypo-Vit E. Propylthiouracil (PTU) was given in drinking water (0.05%) during 6 weeks. Vit E (20 mg/ kg) was daily injected (IP). To evaluate synaptic plasticity, LTP from the CA1 area of the hippocampus followed by high frequency stimulation to the ipsilateral Schafer collateral pathway was carried out. The cortical and hippocampal tissues were then removed to measure NO metabolites. The brains of 5 animals in each group were removed for apoptosis study. The hypothyroidism status decreased the slope, 10–90% slope and amplitude of field excitatory post synaptic potential (fEPSP) compared to the control group (P<0.01–P<0.001). Injection of Vit E increased the slope, 10–90% slope and amplitude of the fEPSP in the Hypo-Vit E group in comparison to the Hypo group (P<0.05–P<0.01). TUNEL positive neurons and NO metabolites were higher in the hippocampus of the Hypo rats, as compared to those in the hippocampus of the control ones (P<0.001). Treatment of the Hypo rats by Vit E decreased apoptotic neurons (P<0.01–P<0.001) and NO metabolites (P<0.001) in the hippocampus compared to the Hypo rats. The results of the present study showed that Vit E prevented the LTP impairment and neuronal apoptosis in the hippocampus of juvenile hypothyroid rats.

scholarly journals Intracerebroventricular injection of oxidant and antioxidant molecules affects long-term potentiation in urethane anaesthetized rats

2008 ◽  
pp. 269-273
Author(s):  
A Viggiano ◽  
E Viggiano ◽  
M Monda ◽  
A Viggiano ◽  
S Ascione ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Dentate Gyrus ◽  
Long Term Potentiation ◽  
Control Group ◽  
High Frequency Stimulation ◽  
Perforant Pathway ◽  
Term Potentiation ◽  
Stimulation Of

Production of superoxide anions in the incubation medium of hippocampal slices can induce long-term potentiation (LTP). Other reactive oxygen species (ROS) such as hydrogen peroxide are able to modulate LTP and are likely to be involved in aging mechanisms. The present study explored whether intracerebroventricular (ICV) injection of oxidant or antioxidant molecules could affect LTP in vivo. With this aim in mind, field excitatory post-synaptic potentials (fEPSPs) elicited by stimulation of the perforant pathway were recorded in the dentate gyrus of the hippocampal formation in urethane-anesthetized rats. N-acetyl-Lcysteine, hydrogen peroxide (H2O2) or hypoxanthine/xanthineoxidase solution (a superoxide producing system) were administrated by ICV injection. The control was represented by a group injected with saline ICV. Ten minutes after the injection, LTP was induced in the granule cells of the dentate gyrus by high frequency stimulation of the perforant pathway. Neither the H2O2 injection or the N-acetyl-L-cysteine injection caused any variation in the fEPSP at the 10-min post-injection time point, whereas the superoxide generating system caused a significant increase in the fEPSP. Moreover, at 60 min after tetanic stimulation, all treatments attenuated LTP compared with the control group. These results show that ICV administration of oxidant or antioxidant molecules can modulate LTP in vivo in the dentate gyrus. Particularly, a superoxide producing system can induce potentiation of the synaptic response. Interestingly, ICV injection of oxidants or antioxidants prevented a full expression of LTP compared to the saline injection.

scholarly journals Causal evidence for LTP-based interference in visual learning

2018 ◽  
Author(s):  
Ji Won Bang ◽  
Diana Milton ◽  
Yuka Sasaki ◽  
Takeo Watanabe ◽  
Dobromir Rahnev
Keyword(s):  
Human Subjects ◽  
Visual Learning ◽  
Strong Support ◽  
Long Term Potentiation ◽  
Control Site ◽  
Theta Burst Stimulation ◽  
Term Potentiation ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

AbstractTraining related skills in close succession results in interference but the reasons for this interference are not understood. Here we test the hypothesis that interference occurs due to competition of long-term potentiation (LTP): the LTP induced by one task impedes the LTP induced by the other. Human subjects performed two consecutive training sessions on different Gabor orientations. Immediately after the offset of the first training, we applied continuous theta burst stimulation (cTBS) to interfere with the LTP processes produced by the first training. We found that cTBS to a control site (vertex) resulted in substantial anterograde interference for the second training. Critically, cTBS to the visual cortex not only disrupted learning on the immediately preceding training, but also released the second training from the anterograde interference. These results provide strong support for the LTP-based theory of interference and suggest the possibility of directly manipulating the competition between different learning periods.

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