The Multifaceted Dopamine

Neurotransmitters, like dopamine, play a critical role in both how neuroscientists study the brain and in how the brain operates. Dopamine itself has a range of purposes, from motor control to motivation and pleasure. Some of these roles are explored in the study conducted by Steidl et al. (2017). In this study, the knowledge that mesopontine tegmental inputs to the dopamine system contribute to motivated behaviors was used to study sensitive sites of the ventral tegmental area (VTA) and rostromedial tegmental nucleus (RMTg). In doing this, the critical role of the RMTg and VTA in recruiting mesopontine inputs in response to the rewarding effects of opioids was better understood. The data supported that these areas GABA-DA disinhibition alone were not responsible for the rewarding effects, therefore a new model for midbrain and pontine control was put forth. This led me to explore other pathways in which dopamine mediates behavioral responses. 

Another dopamine pathway, which is still not fully understood, has been believed to play a role in the development of schizophrenia. Evidence suggests that the disruption of dopamine pathways, such as the ones previously discussed, causes schizophrenia to originate. This change within the pathway itself affects how dopamine is released in addition to what it is released in response to. Therefore, when the rate of dopamine firing in the VTA is altered, either increased or inhibited, it could induce psychosis. Grace and Gomes (2018), in short, suggest that these alterations to the dopaminergic pathways may change how we respond to stressors. These stressors could be perceived as heightened due to genetic predispositions and/ or environmental circumstances. This corresponds to the idea that abusing substances, such as opioids, may correspond to developing schizophrenia (NIDA, 2021). This research shows opioids can affect the dopamine pathways in the VTA, altering the frequency at which neurons fire. As shown in Grace and Gomes's work, this may be responsible for the transition to schizophrenia. 

Taken together, these studies both illustrate the diverse role of dopamine, from mediating reward to playing a role in psychological disorders. Although dopamine is one of the better-understood neurotransmitters, the nuances of its ability throughout many processes are not well known. This knowledge only illustrates the need for continual research and understanding of dopamine. 

 

Works Cited:

Grace, A. A., & Gomes, F. V. (2018, January 29). Circuitry of dopamine system regulation and its disruption in schizophrenia: Insights into treatment and prevention. OUP Academic. Retrieved March 3, 2022, from https://academic.oup.com/schizophreniabulletin/article/45/1/148/4827886?login=true 

Stephan Steidl, PhD - Publications. Stephan Steidl - Publications. (n.d.). Retrieved March 3, 2022, from https://neurotree.org/beta/publications.php?pid=64691&searchstring=&showfilter= 

https://americanaddictioncenters.org/schizophrenia-and-addiction