Assignment: Trichromatic And Opponent-Process Theory

All essay questions require a minimum of 300 words of content analysis (not including the citations and references). Quoting is not permitted. All answers must be paraphrased in your own words.

Describe the process of action potential conduction and neurotransmission from one neuron to another, both electrically (including saltatory conduction) and chemically. Describe how a cell fires an action potential and be sure to address which structures are involved in neurotransmission. Discuss reuptake and enzymatic degradation (breakdown) in the context of the appropriate neurotransmitters.

Trace in detail the structure and function of the visual system from the physical stimuli (light waves), to the structure of the eye and through the corresponding brain structures until it is processed as visual information. You will need to compare photoreceptors in darkness to photoreceptors receiving light and describe how light energy is transduced into neural signals. Describe how the trichromatic and opponent-process theory explain how light of different wavelengths is converted into color information.

Discuss some of the methodological approaches that can be used to examine the influence of multiple genes on behavior. Then discuss what transgenic animals are and how they are produced.

What is the medial forebrain bundle? Discuss the evidence for and against its involvement in reward. In addition, review the evidence showing that the brain’s dopamine pathways are critically involved in pleasure and reward.

What is the monoamine theory of depression? What evidence supports this hypothesis as a cause of affective disorder? It generally takes 2-3 weeks of chronic treatment before an antidepressant begins to have a clinical benefit, yet the drug’s pharmacological effect (for example, its inhibition of MOA, or reuptake) is immediate. What synaptic mechanisms may underlie this time lag?

Critically evaluate the roles of the lateral hypothalamus and ventromedial hypothalamus in hunger and satiety. What other brain sites are known to be involved in eating behavior? How can this be explained in terms of a homeostatic model? What evidence shows that non- homeostatic mechanisms also contribute to feeding?

Describe the brain structures and anatomical pathways that make up the extrapyramidal and pyramidal motor systems. What are the main functions of these two systems? What regions in the cerebral cortex are known to be involved in movement? How do these areas contribute to the production of motor behavior?

How is the brain capable of “seeing” a spectrum of fine color when the eye contains only three different types of color detectors? What evidence supports the existence of dorsal (“where is it?”) and ventral (“what is it?”) visual systems in the cerebral cortex?

Describe the main structures of the brain stem, the midbrain, and forebrain, including the basal ganglia, the limbic system and the cerebral cortex. What functions and behaviors are these regions known to control?