Search results for "Neurotransmitter"
showing 10 items of 275 documents
Effects of CGS 10746B on hyperactivity and place preference induced by morphine
2001
The effects of CGS 10746B, a dopamine release inhibitor, on spontaneous locomotor activity, morphine-induced hyperactivity, acquisition of conditioned place paradigm and morphine-induced conditioned place preference (CPP) was evaluated in male mice. In experiment 1, animals treated with CGS 10746B (0.5, 1, 2, 4, 8, 16, 24 and 32 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus CGS 10746B (0.5, 1, 2, 4, 8, 16, 24 and 32 mg/kg) were placed in an actimeter during a period of 90 min. In experiment 2, animals treated with CGS 10746B (0.5, 1, 3 and 10 mg/kg), morphine (40 mg/kg) or morphine (40 mg/kg) plus CGS 10746B (0.5, 1, 3 and 10 mg/kg) were conditioned following a procedure unbiased …
Pravastatin treatment causes a shift in the balance of hippocampal neurotransmitter binding densities towards inhibition
2009
Since pravastatin, a HMG-CoA reductase inhibitor, has recently been shown to reduce infarct volumes and glutamate release in a rat model of ischemic stroke, the aim of the present study was to investigate whether this neuroprotective effect may be due to a modulation of excitatory and inhibitory neurotransmitter receptors. Therefore, Wistar rats were treated six times in 4 days with pravastatin or saline and allowed to survive for 6 hours or 5 days (n=10 per time point and group), respectively. Using quantitative receptor autoradiography, ligand binding densities of [(3)H]MK-801, [(3)H]AMPA, and [(3)H]muscimol for labeling of NMDA, AMPA, and GABA(A) receptors were analyzed in sensorimotor c…
Long-Term Effects of Dietary Sodium Intake on Cytokines and Neurohormonal Activation in Patients With Recently Compensated Congestive Heart Failure
2009
Abstract Background A growing body of evidence suggests that the fluid accumulation plays a key role in the pathophysiology of heart failure (HF) and that the inflammatory and neurohormonal activation contribute strongly to the progression of this disorder. Methods and Results The study evaluated the long-term effects of 2 different sodium diets on cytokines neurohormones, body hydration and clinical outcome in compensated HF outpatients (New York Heart Association Class II). A total of 173 patients (105 males, mean age 72.5±7) recently hospitalized for worsening advanced HF and discharged in normal hydration and in clinical compensation were randomized in 2 groups (double blind). In Group …
Wasp venom injected into the prey's brain modulates thoracic identified monoaminergic neurons.
2005
The wasp Ampulex compressa injects a cocktail of neurotoxins into the brain of its cockroach prey to induce an enduring change in the execution of locomotory behaviors. Our hypothesis is that the venom injected into the brain indirectly alters the activity of monoaminergic neurons, thus changing the levels of monoamines that tune the central synapses of locomotory circuits. The purpose of the present investigation was to establish whether the venom alters the descending control, from the brain, of octopaminergic neurons in the thorax. This question was approached by recording the activity of specific identified octopaminergic neurons after removing the input from the brain or after a wasp s…
The contribution of acetylcholine and dopamine to subprocesses of visual working memory--what patients with amnestic mild cognitive impairment and Pa…
2014
Attentional selection, i.e. filtering out of irrelevant sensory input and information storage are two crucial components of working memory (WM). It has been proposed that the two processes are mediated by different neurotransmitters, namely acetylcholine for attentional selection and dopamine for memory storage. However, this hypothesis has been challenged by others, who for example linked a lack in dopamine levels in the brain to filtering deficits. Here we tested the above mentioned hypothesis in two patient cohorts which either served as a proxy for a cholinergic or a dopaminergic deficit. The first group comprised 18 patients with amnestic mild cognitive impairment (aMCI), the second 22…
Maize based diets and possible neurobehavioural after-effects among some populations in the world
1996
Maize is a cereal particularly lacking in tryptophan, which is the precursor of serotonin, an important neurotransmitter. Altough complementary foods may eliminate tryptophan deficiency, serotonin deficiency may often continue to exist because of competition made by other Large Neutral Amino Acids (LNAA) against tryptophan for neuron access, since they use the same carrier to cross the blood-brain barrier. Thus serotonin synthesis depends on two variables: the amount of tryptophan and the trp/LNAA ratio (R). “R” is lowest for common maize, low for beans and, as a rule, for most vegetable foods, higher for meat. So, when maize is the preponderant food in the meal, the “R” value lowers and so…
Stimulation of hippocampal acetylcholine release by hyperforin, a constituent of St. John’s Wort
2004
Abstract Extracts of the medicinal plant St. John’s Wort ( Hypericum perforatum ) are widely used in the therapy of affective disorders and have been reported to exert antidepressant, anxiolytic, and cognitive effects in experimental and clinical studies. We here report that hyperforin, the major active constituent of the extract, increases the release of acetylcholine from rat hippocampus in vivo as determined by microdialysis. Hippocampal acetylcholine levels were increased by 50–100% following the systemic administration of pure hyperforin at doses of 1 and 10 mg/kg. The effect was almost completely suppressed by local perfusion with calcium-free buffer or with tetrodotoxin (1 μM). We co…
Synthesis, in vitro activity, and three-dimensional quantitative structure-activity relationship of novel hydrazine inhibitors of human vascular adhe…
2010
Vascular adhesion protein-1 (VAP-1) belongs to the semicarbazide-sensitive amine oxidases (SSAOs) that convert amines into aldehydes. SSAOs are distinct from the mammalian monoamine oxidases (MAOs), but their substrate specificities are partly overlapping. VAP-1 has been proposed as a target for anti-inflammatory drug therapy because of its role in leukocyte adhesion to endothelium. Here, we describe the synthesis and in vitro activities of novel series of VAP-1 selective inhibitors. In addition, the molecular dynamics simulations performed for VAP-1 reveal that the movements of Met211, Ser496, and especially Leu469 can enlarge the ligand-binding pocket, allowing larger ligands than those s…
Studies of the Hypothalamus-Pituitary-Adrenocortical System: An Example of Progress in Psychoneuroendocrinology
1986
Psychobiological study of affective disorders has passed through several phases during the last three decades. With the discovery of thymoleptic drugs and our partial understanding of their pharmacological properties, a dominant theme in psychiatric research came to be the pathophysiology underlying depressive illness. Since enhancement of monoamine neurotransmission was found to be a common characteristic of most antidepressants, several attempts were made to test the hypothesis of a defective cerebral monoamine transmission as the prime cause of depression. In this context, neuroendocrinology became an area that was of particular interest to investigators, for several reasons. Basic resea…
Animal Models of Stress - Current Knowledge and Potential Directions
2021
Finding new therapies and new antidepressant agents is of high clinical priority given that many cases of depressive disorder do not respond to conventional monoaminergic antidepressants such as selective serotonin reuptake inhibitors, tricyclic antidepressants, and monoamine oxidase inhibitors The authors demonstrated that electroacupuncture and fluoxetine, a second-generation antidepressant categorized as a selective serotonin reuptake inhibitor (Perez-Caballero et al , 2014), regulate the expression of key proteins in the calmodulin kinase (CAMK) signaling pathway, which are related to depression in the hippocampi of rats (Takemoto-Kimura et al , 2017;Xie et al , 2019) In a paper on “Sho…