Monday, November 14, 2011

Monkey See, Monkey Remember (Better?)


As our society advances, we are continually finding new ways to enhance the longevity of life and increase the quality of life as it increases. However, while you can continually replace vital organs in the body, there is one organ that is irreplaceable: the brain. Unfortunately, the brain is also one of organs that is most affected by aging (Min et al. 2011). And it is because of the effects of aging that such degenerative diseases such as Parkinson's and Alzheimer's are a semi-common occurrence in our aging society.

However, the technology and research on the brain continues to advance as well, as the field of neuroscience grows. And one of the main areas of study is memory and the mechanisms that help us remember (Min et al. 2011). As we age, it has been shown that our cognitive functioning (including memory) decreases. It has been shown that the majority of this cognitive degeneration occurs first in the prefrontal cortex (PFC) of the brain (Min et al. 2011). Schematically and theoretically, the working memory (the mechanism that pulls out old information and stores new information) is impaired, resulting in memory problems.

As useful as cognitive psychology is, researchers wanted to understand the physiological mechanism(s) responsible, or what they believe are responsible, for this memory impairment. In this current study by Min et al. (2011), a well supported hypothesis was tested to see if memory would improve once the physiology of the brain was 'corrected'.

It is believed that elevated cAMP signaling in neurons reducing the firing by opening hyperpolarizing channels on the neurons (Min et al. 2011). In particular, increased cAMP signaling the PFC has been linked to memory impairment. The current study attempts to do an in vivo recording of PFC neurons in aged monkeys.

In the experiment, monkeys were trained in a spatial working memory task (aka they had to remember a spatial location after a delay period). PFC recordings were done and showed marked memory impairment (Min et al. 2011) as well as increased cAMP signaling. In order to study memory improvement, drugs that inhibit cAMP signaling or prevent hyperpolarization were used. And as the results of this study found, the firing of the neurons was partially restored, thus strengthening cognitive ability and memory (Min et al. 2011).

So all that is good and an improvement towards future research, but I still have some questions!:

1) While the brain may lessen in its degradation, I feel like at some point the cognitive functioning of a person is just gonna give out. Thoughts?

2) The drugs used were highly specified (also I didn't understand part of it) but I feel like the drugs to restore physiological functioning would only be effective for so long and have a load of side effects. What does other effects does inhibiting cAMP have?

Works Cited
Min, W., Gamo, N. J., Yang, Y., Jin, L. E., Xiao-Jing, W., Laubach, M., & ... Arnsten, A. T. (2011). Neuronal basis of age-related working memory decline. Nature, 476 (7359), 210-213. doi:10.1038/nature10243

2 comments:

  1. Sadly, my grandmother “Nettie Dearborne” suffered from this form of dementia. The doctor stated the cause was neurological, and may have been due to the accumulation of protein amyloid plaque. I strongly agree that treating Alzheimer’s with highly specified drugs would be a disadvantage to other vital physiological functions.

    It is believed according to Martini (2006), that a reduction of cAMP concentrations cause vasoconstriction thus elevating blood levels, which may lead to heart problems.

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  2. I am sure that the vasoconstriction will be combated with another drug to keep blood levels normal. However, do you believe that this will only perpetuate a cascade of side of effects for the patient resulting in temporary relief?

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