GPS Of Our Mind Gets An Update

Hippocampus structure

           Did you know the brain is not fully developed at birth? Rather, some structures' plasticity begin to develop as new environmental experiences occur. A specific example of this is the hippocampus' ability to store new short-term memory, long-term memory and spatial navigation from visual stimuli. If the brain is a book and the pages are memories, the hippocampus is the table of contents. It stores some memory and has the ability to locate and extract memories in other parts of the brain. Since the hippocampus is also involved in spatial navigation, can a developing hippocampus be altered using drugs to enhance its capability to navigate?

           

           Dr. Ted Dumas, assistant professor at the Department of Molecular Neuroscience from the Krasnow Institute at George Mason University, conducted a lecture during my neuroscience class discussing his and his team’s research experiment on enhancing developing rat hippocampus using ampakine, specifically  CX614 . In his PBNJ (Physiological and Behavioral Neuroscience in Juveniles) lab, the experiment included two test groups of rats, age 17-19 days and 22-24 days old. 

An example of a Y-maze

            The rats were individually placed in the middle of a Y shape maze for eight minutes and their behavior was observed. The juvenile rats with an intact hippocampus had a 60-70% alternation rate. Another group of juvenile rats had their eyelids sliced open four days before they naturally open, giving them more visual experience. A result of that group suggested they had a more developed hippocampus. In other words, rats injected with CX614 and sliced eye lids had greatest alternation rates than the other test groups which suggest the drug CX614 does impact the hippocampus.

Since CX614 enhances the hippocampus, can it have negative effects of other areas of the brain? Dr. Dumas and his team tested if anxiety levels are altered by the drug. The experiment included an X shaped maze with two arms longer, thus to intimidate the juvenile rats. The time spend in short and long arms was equal thus the subjects experienced no anxiety and fear. This suggests CX614 affects only spatial memory. Dr. Dumas’s lab focused only on juvenile rat brain. He stated a mature brain is different and would not respond to CX614 as effectively. This is because ampakines facilitates the induction of activity-dependent synaptic potentiation. For example, while the PBNJ lab showed that a combination of ampakines and electrical signal resulted in long-term potentiation, mature animals have a decreased desensitization so the drug has a lesser effect.

A Tardigrade

PBNJ’s research opens new ideas and raises questions about how the hippocampus and memory works. So what is PBNJ doing to further study this topic? Dr. Dumas and his team began studying tardigrades. Since these microscopic multicellular organisms have a nervous system and can be killed and brought back to life, tardigrades will be used to distinguish whether storing memories is dependent on consistent structure of neurons or functional change. I think this study will provide a scientific breakthrough as to how our memory works and if we can enhance it to cure diseases such as Alzheimer’s which is predicted to affect 1 in 85 people globally by 2050.

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