Month: April 2015

Neurogenesis: An Introduction

This first year of my PhD program has been fantastically interesting, to say the least:

  • I cofounded a Neuroscience magazine
  • I learned how to functionally image a human brain and how this technology is used in emotional processing with Dr. Mariann Weierich
  • I learned to record the electrical activity of neurons and how this activity is different during a seizure with Dr. Dan McCloskey

All the while, taking classes such as Neural Systems and Behavior, Neuroscience and Law, and Science Diplomacy. So, I’ve been busy.

With the summer coming up, I sense a freeing-up of time as well as a coming motivation to write more. This motivation comes mainly from the fact that I’ve chosen the lab I’ll do my thesis in: Dr. Carolyn Pytte’s neurogenesis and behavior lab.

Neurogenesis refers the process by which new neurons are born into the adult brain. Though it was once assumed that people were born with all the brain cells they’ll ever have, this was found to be a myth. In a 1998 paper published in Nature, Eriksson et al showed that adult humans have neurons expressing a biomarker called BrdU. I’ll be mentioning BrdU a lot, so pay attention.

BrdU is a molecule that can bind to DNA when it’s being replicated in a cell nucleus during mitosis – it binds to DNA in newborn cells. Also, it’s fluorescent, so we can see it. Since every other type of cell also divides, we use neuronal markers such as NeuN which only tags neurons. So any cell containing BrdU is a newborn cell, and any cell containing NeuN is a neuron. Thus, any cell containing both, is a newborn neuron. There are other ways to tags newborn neurons as well.

One of the coolest parts about this process is how amazing the pictures are:

Image from Dr. Paul Frankland’s lab at the University of Toronto. The structure shown here is the dentate gyrus, a region of the brain where new neurons are born. This region is also important for memory.

I agree, neurogenesis IS quite attractive.

But if it were only pretty pictures, we wouldn’t spend so much time researching it. Neurogenesis has important implications for learning and memory. Brains can birth 10,000 new neurons every day. And the rate at which new cells are birthed can depend on things such as how enriched your environment is, or how much you exercise (but, only voluntary exercise increases rates of neurogenesis).

There’s a lot going on concerning this interesting phenomenon and I’m going to be telling you all about it.

Whether you like it or not.

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