za dec 13, 2014 11:37 am
za dec 13, 2014 12:04 pm
za dec 13, 2014 12:24 pm
zo dec 14, 2014 12:24 pm
karl201 schreef:Oh oké bedankt! Ik was benieuwd in dit antidepressief effect en hoe het zou zijn dan
maar oké ketamine kopen dan maar eens haha
ma dec 15, 2014 2:50 am
ma dec 15, 2014 3:39 am
The actions of NMDA receptor antagonists on mTOR signaling and on the density and function of spine synapses represents a fundamental shift in our understanding of the mechanisms underlying rapid acting, efficacious antidepressant treatments. The ability of ketamine to increase synaptogenesis could thereby rapidly reverse the structural deficits resulting from chronic stress exposure that are thought to contribute to depressive symptoms. Sustained induction of negative regulators of BDNF-ERK signaling, such as MKP-1, could also contribute to the atrophy of neurons and decreased volume of limbic brain regions in depression.
The mTOR translational system can be influenced, both positively and negatively by a variety of neurotransmitter, endocrine, and metabolic signaling pathways, and could thereby serve as a nexus for control of synaptogenesis. This complex regulatory system raises the possibility that there are additional negative regulators of mTOR signaling and synaptogenesis that play a role in neuronal atrophy caused by stress exposure, an area that is under active investigation. Conversely, pathways that enhance mTOR signaling could also be targeted for novel therapeutic approaches for the treatment of depression, although the ubiquitous expression and function of mTOR raises the possibility of side effects. Never- theless, novel targets that influence glutamate transmission, BDNF- mTOR signaling, and synaptogenesis offer promise for the devel- opment of safer, rapid acting and efficacious antidepressant agents for the treatment of depression.
Clinical studies demonstrate that ketamine produces a rapid antidepressant response.
Ketamine rapidly increases synaptogenesis in rodent prefrontal cortex.
Ketamine-induction of synaptogenesis requires mTOR signaling.
Ketamine rapidly reverses synaptic loss caused by stress and depression.
Ketamine results in a functional reconnection of neurons.
ma dec 15, 2014 7:36 am
ma dec 15, 2014 7:49 am
When NMDA antagonists are administered in high enough doses to mature brain cells, sufficient disruption of homeostatic glutamate transmission results in irreversible excitotoxic degeneration via necrosis.
http://www.jbrf.org/ketamine-clinical-trial/the-neurodegenerative-and-neuroprotective-effects-of-ketamine/When NMDA antagonists are administered in significantly lower doses than suggested above, they promote robust and rapid neurogeneration. It is this action which reverses the neuronal atrophy and loss of connectivity that characterizes psychiatric disorders such as depression and bipolar disorder.
Accumulating evidence indicates that disturbances of neuroplasticity occur with depression, including reductions of hippocampal neurogenesis and cortical synaptogenesis. Improper trophic support stemming from stressor-induced reductions of growth factors, most notably brain derived neurotrophic factor (BDNF), likely drives such aberrant neuroplasticity.
ma dec 15, 2014 9:01 am
Fool schreef:De anti-depressive werking van ketamine is niet gebaseerd op het NMDA-antagonisme als direct effect. Onderstaande stukje is best interessant:
Signaling Pathways Underlying the Rapid Antidepressant Actions of Ketamine (2011)The actions of NMDA receptor antagonists on mTOR signaling and on the density and function of spine synapses represents a fundamental shift in our understanding of the mechanisms underlying rapid acting, efficacious antidepressant treatments. The ability of ketamine to increase synaptogenesis could thereby rapidly reverse the structural deficits resulting from chronic stress exposure that are thought to contribute to depressive symptoms. Sustained induction of negative regulators of BDNF-ERK signaling, such as MKP-1, could also contribute to the atrophy of neurons and decreased volume of limbic brain regions in depression.
The mTOR translational system can be influenced, both positively and negatively by a variety of neurotransmitter, endocrine, and metabolic signaling pathways, and could thereby serve as a nexus for control of synaptogenesis. This complex regulatory system raises the possibility that there are additional negative regulators of mTOR signaling and synaptogenesis that play a role in neuronal atrophy caused by stress exposure, an area that is under active investigation. Conversely, pathways that enhance mTOR signaling could also be targeted for novel therapeutic approaches for the treatment of depression, although the ubiquitous expression and function of mTOR raises the possibility of side effects. Never- theless, novel targets that influence glutamate transmission, BDNF- mTOR signaling, and synaptogenesis offer promise for the devel- opment of safer, rapid acting and efficacious antidepressant agents for the treatment of depression.Clinical studies demonstrate that ketamine produces a rapid antidepressant response.
Ketamine rapidly increases synaptogenesis in rodent prefrontal cortex.
Ketamine-induction of synaptogenesis requires mTOR signaling.
Ketamine rapidly reverses synaptic loss caused by stress and depression.
Ketamine results in a functional reconnection of neurons.
Ik snap het mechanisme ook niet helemaal, misschien dat iemand anders het beter uit kan leggen. Klinkt in ieder geval behoorlijk interessant, helemaal de dikgedrukte conclusies.
ma dec 15, 2014 9:14 am
ma dec 15, 2014 9:56 am
Maurits schreef:Als er in de wetenschappelijke literatuur gesproken wordt over 'lage doseringen', over welke ranges van doseringen spreken we dan?
- Andrade C. Innovative approaches to treatment-refractory depression: The Ketamine Story. Synergy Times. 2010:10.In most of these studies, ketamine was administered in the dose of 0.5 mg/kg as an intravenous infusion in 50-100 ml of normal saline over a period of 40 minutes.
- Daily oral ketamine for the treatment of depression and anxiety in patients receiving hospice care: a 28-day open-label proof-of-concept trial. (Aug, 2013)METHODS: In this open-label study, 14 subjects with symptoms of depression or depression mixed with anxiety warranting psychopharmacological intervention received daily oral doses of ketamine hydrochloride (0.5 mg/kg) over a 28-day period. The primary outcome measure was the Hospital Anxiety and Depression Scale (HADS), which was used to rate overall depression and anxiety symptoms at baseline, and on days 3, 7, 14, 21, and 28
CONCLUSIONS: Patients who received daily oral ketamine experienced a robust antidepressant and anxiolytic response with few adverse events. The response rate for depression is similar to those found with IV ketamine; however, the time to response is more protracted.
ma dec 15, 2014 10:07 am
Claviceps schreef:Maurits schreef:Als er in de wetenschappelijke literatuur gesproken wordt over 'lage doseringen', over welke ranges van doseringen spreken we dan?
Dat kan per studie variëren. Daarnaast is de toedieningsvorm meestal IV of IM.- Andrade C. Innovative approaches to treatment-refractory depression: The Ketamine Story. Synergy Times. 2010:10.In most of these studies, ketamine was administered in the dose of 0.5 mg/kg as an intravenous infusion in 50-100 ml of normal saline over a period of 40 minutes.
Iemand van 70kg krijgt dus 70*0.5 = 350 mg in totaal toegediend over een periode van 40 minuten.
ma dec 15, 2014 10:09 am
ma dec 15, 2014 10:47 am
Claviceps schreef:Heb de post net nog aangepast Maurits er staan nu details in over orale dosering. Waar je trouwens wel rekening mee dient te houden is dat de populatie die geselecteerd is voor deze studies mogelijk ergere klachten hebben dan jouw. Vaak gaat het om patienten die geen/weinig resultaat hebben bij andere vormen van therapie en medicatie.
ma dec 15, 2014 10:51 am
ma dec 15, 2014 2:44 pm