Answer the three questions
1.Choose a brain region and a behavior this region is thought to control. Describe at least one other brain region that is involved in the execution of this behavior. How do these two regions communicate to execute this behavior? Comment on whether synaptic or hormonal communication (or both) are employed by these brain regions to complete your chosen behavior.
2.Draw a conclusion about the way we localize functions in the brain: Are we justified in using brain lesions to understand “normal” brain functions? Should we reevaluate our old hypotheses concerning localization of function, given the development of neuroimaging techniques? Explain. There is no strictly right or wrong answer to this question, but only thoughtful responses.
3.Choose a step in synaptic communication and explain what might happen if you were to perturb this step. Is communication increased, decreased or in some other way changed? Support your hypothesis by describing one drug that alters synaptic communication in this way. (Hint: be sure to include in your answer to what receptors the drug binds in the brain and how this binding alters neuronal communication).
In 75-100 words respond to the two students
student 1
- The Broca’s area is responsible for the production of speech and syntax. A second region of the brain that works with this area is Wernicks area, which is responsible for comprehension of the language. These two regions are connected by nerves which rapidly transmit data back and forth (Lyons et al., 2012). Synaptic communication is required to complete this behavior.
- I believe we are justified in using brain lesions to understand a “normal” brain. The ability to study brains help us gain more understanding of how they function. This question made me think of CTE (chronic traumatic encephalopathy) and how the research for that mainly occurs after someone passes away from the condition. The previous understanding should continue to be reevaluated as new techniques become available. The ability to gain a better understanding can lead to better treatment options for those people requiring it. As someone who has had a few TBIs, it was many years before I learned the Army has entire clinics dedicated to Soldiers with TBIs.
- During the synaptic communication, dopamine can cause different reactions. An excess of dopamine during the presynaptic receptors can cause the receptors to fail to maintain a normal level of dopamine in the body (Jaurez et al., 2016). A low level of dopamine has been linked as a potential cause of ADHD. Medicines used to treat ADHD, such as Ritalin, work by increasing the levels of dopamine and norepinephrine in the brain.
Student 2
Question 1
The prefrontal cortex (PFC) is critical for executive functions, including decision-making and impulse control. Another brain region involved in these behaviors is the amygdala, which processes emotions. The PFC and amygdala communicate through neural pathways that allow the PFC to modulate emotional responses generated by the amygdala. This communication is primarily synaptic, involving neurotransmitters like glutamate and GABA, which facilitate excitatory and inhibitory signals, respectively. Hormonal influences, such as cortisol during stress, can also affect this interaction, indicating that both synaptic and hormonal communications are crucial in the regulation of behavior by these brain regions.
Question 2
Using brain lesions to understand normal brain functions has been historically valuable but has limitations. Lesions can reveal the role of a brain region by observing deficits that arise from damage; however, they may not account for compensatory mechanisms or network-level functions. Neuroimaging techniques, such as fMRI and PET scans, offer more nuanced insights by showing functional connectivity and brain activity in real-time. While lesions provide crucial information about localized functions, neuroimaging suggests that brain functions are more distributed and interdependent, warranting a reevaluation of older hypotheses on localization.
Question 3
If the reuptake step in synaptic communication is perturbed, communication can be significantly altered. For instance, inhibiting the reuptake of serotonin increases its availability in the synaptic cleft, enhancing serotonergic transmission. Selective serotonin reuptake inhibitors (SSRIs) like fluoxetine bind to serotonin transporters, blocking reuptake and thus increasing serotonin levels. This action can alleviate symptoms of depression by enhancing mood-regulating pathways in the brain. Therefore, perturbing reuptake generally increases synaptic communication for the affected neurotransmitter.
