Neuroprotection
Bluelighter
- Joined
- Apr 18, 2015
- Messages
- 1,264
I should’ve probably posted this in the neuroscience and pharmacology forum, however, I don’t seem to get many responses to anything I post there and also, I feel this subject is more relevant to people on this particular forum. I ask everyone to forgive me for my long posts and any grammatical errors as I am blind and using my iPhone dictation function to type. I have a lot to say but I hope it helps.
Basically, anhedonia is most commonly thought of as a loss of ability to feel pleasure, when in fact, in most cases it is a reward motivation/salience deficiency. this makes affected individuals perceive natural rewards as unworthy of their effort and of little to no value. in such cases, negative emotions usually fill the gap and anxiety sets in. since dopamine is the most studied chemical in this regard, it’s interesting to note that rats depleted of dopamine Will not pursue food and May die of starvation. However, if food is placed in their mouths, they will eat, and they exhibit a strong liking reaction when sugar solution is placed in their mouth. furthermore, even without dopamine, sugar solutions can be reinforcing in rats, although I guess it Took longer to establish and was smaller in magnitude. therefore, it is appropriate to say that dopamine is more involved in wanting rather than liking and drives a pursuit of pleasure rather than the experience of it. based on my own self diagnosed experience of anhedonia, i’ve come up with a theory that dopamine and associated reward seeking/impulsivity gives us a sense of direction and prevents us from overthinking things. in my next post, I will discuss my own personal experience of anhedonia as this one is already quite large, however, I will continue on this post below with some suggestions of methods/substances and ideas related to anhedonia.
As mentioned above, anhedonia is a reward deficiency syndrome and the most common Brain region associated with this is the nucleus accumbens. I know hardly anything about brain Science, but I believe the role of the nucleus accumbens includes reward calculation and attribution of value to the reward as well as the direct experience of reward itself. now, dopamine is the main neurotransmitter in discussions of the nucleus accumbens in reward/drugs of abuse, yet, it is well-known that serotonin, glutamate, and many others are also involved. unfortunately, as we already know, simply boosting dopamine is not sustainable especially if strong Psychostimulants like amphetamine are used.
Interestingly, examining changes in the nucleus accumbens following the long-term administration of addictive drugs or in response to prolonged unpredictable stress and social defeat stress in animals gives us some major clues about the development of anhedonia and how it could be easily reversed.
Apparently, dopamine associated reward is generated by decreased reactivity of certain neurons in the nucleus accumbens. i’m not sure which cells exactly or what this means for other neurons, but I guess it probably disinhibits other systems and acts as a signal that something valuable is being experienced.
So what are the main negative changes associated with long-term stress or drug abuse, and how do they cause anhedonia? to start, both these factors cause an increase in levels of the feel bad peptide Dynnorphin, Which, through activation of kappa opioid receptors decreases, dopamine signalling and release in the nucleus accumbens. interestingly, Kappa Opioid receptor activation also decreases release of glutamate, norepinephrine, GABA and serotonin in the nucleus accumbens and in other brain regions. Dynnorphin must serve some kind of beneficial purpose but it surely a nightmare molecule and disastrous in excess. thankfully, more and more small molecules are becoming available which selectively block the kappa opioid receptor. buprenorphine is apparently a kappa opioid antagonist and it’s combination with a Mu antagonist like naltrexone has been investigated for depression. although clinical trials were not particularly impressive, I feel that perhaps not enough time was given for optimum results. Also, disturbed by the extremely long pharmacological duration of action of the old Kappa antagonists like norbimiltorphamine or JDTIK, researchers instead focus on short-acting molecules that only last a few hours. Frankly, I don’t think that’s enough time, keep in mind that high levels of Dynnorphin and up-regulation of kappa receptors can be operating in the brain for weeks or months at a time. actually, a recent study I came across showed that prolonged Kappa receptor activation lead to long-term changes in expression of glutamate receptors that resulted in despair like behaviour and this behaviour far outlasted The kappa Opioid agonist. with that in mind, perhaps prolonged blockade of the kappa receptor alongside behavioural therapy and healthy lifestyle changes might go a very long way.
I’m less enthusiastic about other substances like Serotonergic psychedelics or NMDA antagonists, due to the range of side-effects, including memory impairment, psychotomimetic reactions or worsening of depression. whilst the NMDA antagonists have produced rapid antidepressant affects, these are short lived and come with the above-mentioned side-effects. additionally, they may paradoxically impair reward learning, interfering with motivation and the acquisition of new rewarding experiences. unlike these substances, the Kappa Opioid antagonists actually possess antipsychotic effects, despite enhancing dopamine release in the brain and producing a state analogous to cocaine sensitisation. extra dopamine with a decreased risk of psychosis sounds wonderful to me.
Sorry for the long rant, just hope to stimulate discussion that will help people for a long time to come.
Basically, anhedonia is most commonly thought of as a loss of ability to feel pleasure, when in fact, in most cases it is a reward motivation/salience deficiency. this makes affected individuals perceive natural rewards as unworthy of their effort and of little to no value. in such cases, negative emotions usually fill the gap and anxiety sets in. since dopamine is the most studied chemical in this regard, it’s interesting to note that rats depleted of dopamine Will not pursue food and May die of starvation. However, if food is placed in their mouths, they will eat, and they exhibit a strong liking reaction when sugar solution is placed in their mouth. furthermore, even without dopamine, sugar solutions can be reinforcing in rats, although I guess it Took longer to establish and was smaller in magnitude. therefore, it is appropriate to say that dopamine is more involved in wanting rather than liking and drives a pursuit of pleasure rather than the experience of it. based on my own self diagnosed experience of anhedonia, i’ve come up with a theory that dopamine and associated reward seeking/impulsivity gives us a sense of direction and prevents us from overthinking things. in my next post, I will discuss my own personal experience of anhedonia as this one is already quite large, however, I will continue on this post below with some suggestions of methods/substances and ideas related to anhedonia.
As mentioned above, anhedonia is a reward deficiency syndrome and the most common Brain region associated with this is the nucleus accumbens. I know hardly anything about brain Science, but I believe the role of the nucleus accumbens includes reward calculation and attribution of value to the reward as well as the direct experience of reward itself. now, dopamine is the main neurotransmitter in discussions of the nucleus accumbens in reward/drugs of abuse, yet, it is well-known that serotonin, glutamate, and many others are also involved. unfortunately, as we already know, simply boosting dopamine is not sustainable especially if strong Psychostimulants like amphetamine are used.
Interestingly, examining changes in the nucleus accumbens following the long-term administration of addictive drugs or in response to prolonged unpredictable stress and social defeat stress in animals gives us some major clues about the development of anhedonia and how it could be easily reversed.
Apparently, dopamine associated reward is generated by decreased reactivity of certain neurons in the nucleus accumbens. i’m not sure which cells exactly or what this means for other neurons, but I guess it probably disinhibits other systems and acts as a signal that something valuable is being experienced.
So what are the main negative changes associated with long-term stress or drug abuse, and how do they cause anhedonia? to start, both these factors cause an increase in levels of the feel bad peptide Dynnorphin, Which, through activation of kappa opioid receptors decreases, dopamine signalling and release in the nucleus accumbens. interestingly, Kappa Opioid receptor activation also decreases release of glutamate, norepinephrine, GABA and serotonin in the nucleus accumbens and in other brain regions. Dynnorphin must serve some kind of beneficial purpose but it surely a nightmare molecule and disastrous in excess. thankfully, more and more small molecules are becoming available which selectively block the kappa opioid receptor. buprenorphine is apparently a kappa opioid antagonist and it’s combination with a Mu antagonist like naltrexone has been investigated for depression. although clinical trials were not particularly impressive, I feel that perhaps not enough time was given for optimum results. Also, disturbed by the extremely long pharmacological duration of action of the old Kappa antagonists like norbimiltorphamine or JDTIK, researchers instead focus on short-acting molecules that only last a few hours. Frankly, I don’t think that’s enough time, keep in mind that high levels of Dynnorphin and up-regulation of kappa receptors can be operating in the brain for weeks or months at a time. actually, a recent study I came across showed that prolonged Kappa receptor activation lead to long-term changes in expression of glutamate receptors that resulted in despair like behaviour and this behaviour far outlasted The kappa Opioid agonist. with that in mind, perhaps prolonged blockade of the kappa receptor alongside behavioural therapy and healthy lifestyle changes might go a very long way.
I’m less enthusiastic about other substances like Serotonergic psychedelics or NMDA antagonists, due to the range of side-effects, including memory impairment, psychotomimetic reactions or worsening of depression. whilst the NMDA antagonists have produced rapid antidepressant affects, these are short lived and come with the above-mentioned side-effects. additionally, they may paradoxically impair reward learning, interfering with motivation and the acquisition of new rewarding experiences. unlike these substances, the Kappa Opioid antagonists actually possess antipsychotic effects, despite enhancing dopamine release in the brain and producing a state analogous to cocaine sensitisation. extra dopamine with a decreased risk of psychosis sounds wonderful to me.
Sorry for the long rant, just hope to stimulate discussion that will help people for a long time to come.