Abstract and References

Abstract

Culture and genes are often considered to be contrary concepts that have little commonality.  However, genes can affect how the brain functions in influencing the formation of cultural norms and also cause an opposite affect by culture possibly shaping the selection and later the expression of genes within a population (Chiao & Blizinsky, 2010). Studies on genetics have suggested that there are gene variations within the central neurotransmitter systems (Way & Lieberman). The neurotransmitter serotonin is considered to have the capability of influencing individual differences in emotional responsiveness to varying social environments (Way & Lieberman, 2010). This literature review will explore the various ways genetic researchers have linked the neurotransmitter serotonin in influencing differences within cultural constructs such as collectivism and individualism within diverse societies. Results from these studies do indicate that there are genetic variations that positively correlate with social and ecological factors causing psycho-cultural differences within societies (Fincher et al., 2008). 

Serotonin Transporter Gene Variants Across the World

Fig 1. Known prevalence of S-S and S-L serotonin transporter gene variants worldwide. Yellow denotes low rates, orange middling rates (around 40-50%, and red high, around 80% (Chiao & Blizinsky, 2009).

Individualism vs. Collectivism 

Yellow: Individualistic Red: Collectivistic  

References

Chiao, J., Blizinsky, K. (2010). Culture-gene coevolution of individualism collectivism and the serotonin transporter gene. Proceedings of the Royal Society B, 277(1681), 529–37.

Fincher, C.L., Thornhill, R., Murray, D.R., Schaller, M. (2008). Pathogen prevalence predicts human cross- cultural variability in individualism/collectivism. Proceedings of the Royal Society B: Biological Sciences, 275(1640), 1279–85.

Way, B. M., & Lieberman, M. D. (2010). Is there a genetic contribution to cultural differences?Collectivism, individualism and genetic markers of social sensitivity. Social Cognitive And Affective Neuroscience, 5(2-3), 203-211.

Chemical Communication in the Nervous System: Glycine

Background and Location of Glycine

Glycine is located in the central nervous system. It is considered a “inhibitory neurotransmitter,” meaning it works to decrease a neuron's action potential (Werman et al., 1967). Glycine is most commonly found in the spinal cord, retina, and brain stem (Werman et al., 1967). It is the simplest amino acid, its main function is to build protein molecules in the body (Werman et al., 1967). While glycine is considered a non-essential amino acid because it can be created from other chemicals in the body, it’s also the second most commonly found amino acid in proteins (McIntire et al., 1997).

Primary Role and Function of Glycine

Glycine processes “motor and sensory information that allows movement, vision, and sound” to be signaled from the brain (Lopez-Corcuera et al., 2001). It’s mostly responsible for transmitting chemical signals in the brain. Glycine is often co-released into the post-synaptic terminal with GABA (gamma-amino butyric acid), which is the prime inhibitory amino acid neurotransmitter (as illustrated in the diagram below) (McIntire et al., 1997). When glycine is released into the synapse (the space between nerve cells), glycine binds to a receptor and makes the post-synaptic membrane (the receiving end across the synapse) more absorbent of chlorine-ion (Lopez-Corcuera et al., 2001). Hyperpolarization then occurs in the membrane, meaning there’s an increase in electrical charge on both sides of the cell membrane which also increases the membrane electric potential (Lopez-Corcuera et al., 2001). Glycine can also sometimes be used as treatment of cognitive disorders or behavioral problems such as schizophrenia, manic depression, alcohol addiction, and hyperactivity (Harvey &Yee, 2013). 

Glycine Video

The video discusses the three prominent amino acids Glutamate, GABA and Glycine. Even though the whole clip is beneficial in understanding the amino acids and how they function in central nervous system, the speaker specifically discusses the function of glycine starting at 4:32.

References

Harvey, R. J., & Yee, B. K. (2013). Glycine transporters as novel therapeutic targets in 

          

          schizophrenia,alcohol dependence and pain. Nature Reviews Drug Discovery, 12(11), 866-885.

Lopez-Corcuera, B., Geerlings, A., & Aragon, C. (2001). Glycine neurotransmitter transporters: an

           

          update. Molecular membrane biology, 18(1), 13-20.

McIntire, S. L., Reimer, R. J., Schuske, K., Edwards, R. H. and Jorgensen, E. M. (1997). 

            

           Identificationand characterization of the vesicular GABA transporter. Nature, 389, 870-876.

Werman, R., Davidoff, R. A. & Aprison, M. H. (1967). Inhibition of motoneurons by iontophoresis 

            of glycine. Nature, 214, 681-683.

University of Utah: An Online Science Lab to Explore

The Reward Pathway Reinforces Behavior

My activity in learning about the reward pathway in the brain wasn't really interactive, it only prompted me to read and click the next button to go on to the following slide explain how the reward pathway operates. 

I learned a lot so I would recommend it overall but if you want a more interactive learning experience maybe this activity isn't the best for that. This activity is appropriate for a naive audience. The concepts were simple to follow and understand, there are also graphics that can guide you long to illustrate the different steps being explained. 

Link to Reward Pathway Activity

Video is a bit long but does a good job explaining how the reward pathway works. 

My pet peeve is when people chew loudly.

Link to noisy chewing article