Hi, thanks for the video. I am still a bit confused about how dopamine is associated with these four pathways. My current understanding is that too much dopamine would cause positive schizophrenic symptoms through the mesolimbic pathway, and too little/much dopamine would cause abnormal body movements through the nigrostriatal pathway. But I was lost when you mentioned in the video that dopamine-related antipsychotics are unlikely to affect the negative schizophrenic symptoms, so how exactly does the dopamine level regulate negative symptoms through the mesocortical pathway?
Great question! I will do my best to explain, but before I do, I want to say 1) this is most definitely beyond the scope of the MCAT and 2) from my understanding, something not completely understood in current literature. Based on the "dopamine hypothesis" of schizophrenia, researchers postulated that increased dopamine in the mesolimbic pathway was at least partly responsible for some of the increased positive symptoms of schizophrenia. This was evidenced practically by antipsychotics, which antagonize the D2 dopamine receptors, attenuating some of the positive symptoms of schizophrenia. Second, expanding on this hypothesis, it was proposed that reduced dopamine-not increased-in the mesocortical pathway may be responsible for some of the negative symptoms of schizophrenia, evidenced by the fact that antipsychotics that are pure antagonists do not generally alleviate negative symptoms like they do positive symptoms. Interestingly, it may be that some of the newer antipsychotics that have a second function as partial agonists at certain dopamine receptors may actually reduce the severity of negative symptoms. (**As a disclaimer, this is not my area of focus and is not intended as medical advice.)
Feel free to leave any questions or video ideas!
Happy New Year! And if you are free to make a video on key points of fatty acids synthesis that would be helpful. Thank you
It's on the list!
Hi, thanks for the video.
I am still a bit confused about how dopamine is associated with these four pathways. My current understanding is that too much dopamine would cause positive schizophrenic symptoms through the mesolimbic pathway, and too little/much dopamine would cause abnormal body movements through the nigrostriatal pathway. But I was lost when you mentioned in the video that dopamine-related antipsychotics are unlikely to affect the negative schizophrenic symptoms, so how exactly does the dopamine level regulate negative symptoms through the mesocortical pathway?
Great question! I will do my best to explain, but before I do, I want to say 1) this is most definitely beyond the scope of the MCAT and 2) from my understanding, something not completely understood in current literature.
Based on the "dopamine hypothesis" of schizophrenia, researchers postulated that increased dopamine in the mesolimbic pathway was at least partly responsible for some of the increased positive symptoms of schizophrenia. This was evidenced practically by antipsychotics, which antagonize the D2 dopamine receptors, attenuating some of the positive symptoms of schizophrenia. Second, expanding on this hypothesis, it was proposed that reduced dopamine-not increased-in the mesocortical pathway may be responsible for some of the negative symptoms of schizophrenia, evidenced by the fact that antipsychotics that are pure antagonists do not generally alleviate negative symptoms like they do positive symptoms. Interestingly, it may be that some of the newer antipsychotics that have a second function as partial agonists at certain dopamine receptors may actually reduce the severity of negative symptoms. (**As a disclaimer, this is not my area of focus and is not intended as medical advice.)
@@medcatmcat Got it. Thank you for your detailed explanation!