Long-term effects of seizures in neonatal rats on spatial learning ability and N-methyl-d-aspartate receptor expression in the brain

2004 ◽  
Vol 152 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Tao Bo ◽  
Yuwu Jiang ◽  
Haiyan Cao ◽  
Jingmin Wang ◽  
Xiru Wu

Meditation refers to a state of mind of relaxation and concentration, where generally the mind and body is at rest. The process of meditation reflects the state of the brain which is distinct from sleep or typical wakeful states of consciousness. Meditative practices usually involve regulation of emotions and monitoring of attention. Over the past decade there has been a tremendous increase in an interest to study the neural mechanisms involved in meditative practices. It could also be beneficial to explore if the effect of meditation is altered by the number of years of meditation practice. Functional Magnetic Resonance Imaging (fMRI) is a very useful imaging technique which can be used to perform this analysis due to its inherent benefits, mainly it being a non-invasive technique. Functional activation and connectivity analysis can be performed on the fMRI data to find the active regions and the connectivity in the brain regions. Functional connectivity is defined as a simple temporal correlation between anatomically separate, active neural regions. Functional connectivity gives the statistical dependencies between regional time series. It is a statistical concept and is quantified using metrics like Correlation. In this study, a comparison is made between functional connectivity in the brain regions of long term meditation practitioners (LTP) and short-term meditation practitioners (STP) to see the differences and similarities in the connectivity patterns. From the analysis, it is evident that in fact there is a difference in connectivity between long term and short term practitioners and hence continuous practice of meditation can have long term effects.


2013 ◽  
Vol 43 (1) ◽  
pp. 79
Author(s):  
R. Ghalamghash ◽  
H.Z. Mammedov ◽  
H. Ashayeri ◽  
A. Hosseini

Author(s):  
Angela Duckworth ◽  

For more than a century, scientists have known that acute stress activates the fight-or-flight response. When your life is on the line, your body reacts instantly: your heart races, your breath quickens, and a cascade of hormones sets off physiological changes that collectively improve your odds of survival. More recently, scientists have come to understand that the fight-or-flight response takes a toll on the brain and the body—particularly when stress is chronic rather than acute. Systems designed to handle transient threats also react to stress that occurs again and again, for weeks, months, or years. It turns out that poverty, abuse, and other forms of adversity repeatedly activate the fight-or-flight response, leading to long-term effects on the immune system and brain, which in turn increase the risk for an array of illnesses, including asthma, diabetes, arthritis, depression, and cardiovascular disease. Pioneering neuroscientist Bruce McEwen called this burden of chronic stress “allostatic load.”


Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 314 ◽  
Author(s):  
Nicole Blanshan ◽  
Hollis Krug

Chronic osteoarthritis pain is an increasing worldwide problem. Treatment for osteoarthritis pain is generally inadequate or fraught with potential toxicities. Botulinum toxins (BoNTs) are potent inhibitors of neuropeptide release. Paralytic toxicity is due to inhibition at the neuromuscular junction, and this effect has been utilized for treatments of painful dystonias. Pain relief following BoNT muscle injection has been noted to be more significant than muscle weakness and hypothesized to occur because of the inhibition of peripheral neuropeptide release and reduction of peripheral sensitization. Because of this observation, BoNT has been studied as an intra-articular (IA) analgesic for chronic joint pain. In clinical trials, BoNT appears to be effective for nociceptive joint pain. No toxicity has been reported. In preclinical models of joint pain, BoNT is similarly effective. Examination of the dorsal root ganglion (DRG) and the central nervous system has shown that catalytically active BoNT is retrogradely transported by neurons and then transcytosed to afferent synapses in the brain. This suggests that pain relief may also be due to the central effects of the drug. In summary, BoNT appears to be safe and effective for the treatment of chronic joint pain. The long-term effects of IA BoNT are still being determined.


2019 ◽  
Vol 46 (3) ◽  
pp. 484-495 ◽  
Author(s):  
Federico E Turkheimer ◽  
Pierluigi Selvaggi ◽  
Mitul A Mehta ◽  
Mattia Veronese ◽  
Fernando Zelaya ◽  
...  

Abstract The use of antipsychotic medication to manage psychosis, principally in those with a diagnosis of schizophrenia or bipolar disorder, is well established. Antipsychotics are effective in normalizing positive symptoms of psychosis in the short term (delusions, hallucinations and disordered thought). Their long-term use is, however, associated with side effects, including several types of movement (extrapyramidal syndrome, dyskinesia, akathisia), metabolic and cardiac disorders. Furthermore, higher lifetime antipsychotic dose-years may be associated with poorer cognitive performance and blunted affect, although the mechanisms driving the latter associations are not well understood. In this article, we propose a novel model of the long-term effects of antipsychotic administration focusing on the changes in brain metabolic homeostasis induced by the medication. We propose here that the brain metabolic normalization, that occurs in parallel to the normalization of psychotic symptoms following antipsychotic treatment, may not ultimately be sustainable by the cerebral tissue of some patients; these patients may be characterized by already reduced oxidative metabolic capacity and this may push the brain into an unsustainable metabolic envelope resulting in tissue remodeling. To support this perspective, we will review the existing data on the brain metabolic trajectories of patients with a diagnosis of schizophrenia as indexed using available neuroimaging tools before and after use of medication. We will also consider data from pre-clinical studies to provide mechanistic support for our model.


2008 ◽  
Vol 21 (1) ◽  
pp. 42-55 ◽  
Author(s):  
Genevieve S. Young ◽  
James B. Kirkland

The pyridine nucleotide NAD+is derived from dietary niacin and serves as the substrate for the synthesis of cyclic ADP-ribose (cADPR), an intracellular Ca signalling molecule that plays an important role in synaptic plasticity in the hippocampus, a region of the brain involved in spatial learning. cADPR is formed in part via the activity of the ADP-ribosyl cyclase enzyme CD38, which is widespread throughout the brain. In the present review, current evidence of the relationship between dietary niacin and behaviour is presented following investigations of the effect of niacin deficiency, pharmacological nicotinamide supplementation and CD38 gene deletion on brain nucleotides and spatial learning ability in mice and rats. In young male rats, both niacin deficiency and nicotinamide supplementation significantly altered brain NAD+and cADPR, both of which were inversely correlated with spatial learning ability. These results were consistent across three different models of niacin deficiency (pair feeding, partially restricted feeding and niacin recovery). Similar changes in spatial learning ability were observed inCd38− / − mice, which also showed decreases in brain cADPR. These findings suggest an inverse relationship between spatial learning ability, dietary niacin intake and cADPR, although a direct link between cADPR and spatial learning ability is still missing. Dietary niacin may therefore play a role in the molecular events regulating learning performance, and further investigations of niacin intake, CD38 and cADPR may help identify potential molecular targets for clinical intervention to enhance learning and prevent or reverse cognitive decline.


2019 ◽  
Vol 10 (4) ◽  
pp. 1219-1227
Author(s):  
Dr.Maida Zameer ◽  
Dr. Sunbal Siddique ◽  
Dr.Maria Baig

Organophosphorous compounds, the anticholinesterases, produce significant morbidity and mortality in Pakistan. Neuropsychological assessment was traditionally carried out to assess the extent of impairment to a particular skill and to attempt to determine the area of the brain which may have been damaged following brain injury or neurological illness. With the advent of neuroimaging techniques, location of space-occupying lesions can now be more accurately determined through this method, so the focus has now moved on to the assessment of cognition and behaviour, including examining the effects of any brain injury or neuropathological process that a person may have experienced.


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