Local Resource: BioCompass Kids (Brainstorm Expedition Class)

Reason #1,982,963 that we feel blessed to homeschool in the Bay Area - how often do you get to meet neuroscientists? And how many of them would jump at the chance to teach a K-12 class? We met Drs. Aarron and Natalia when they did a popup event in Foster City introducing BioCompass Kids, their project to introduce science to children in an accessible yet rigorous way. They agreed to run a 4 hour neuroscience class for our middle and high schoolers. 

When we arrived, they had set out a variety of stations with colorful materials such as those pictured above, and we immediately knew this would be a fun class with hands-on opportunities. They started with an analogy - the brain is like the internet, with grey matter being the nodes/computers and the white matter being the connections between them. 

(Note about photos below: Our class was held on Halloween so our instructors were dressed as mad scientists😀)

Pointing out grey vs white matter

Starting from macrostructures, we learned about main lobes of the cerebrum: frontal, parietal, temporal, occipital. Each has functions, e.g. the frontal lobe controls decision making, the occipital controls visual input. The instructors then distributed some cards with problem scenarios, and asked students to match them to the lobe the problem might lie, e.g. "You can't remember your friends' names (temporal lobe - memory)".  Some were hard - "You try to catch a fast moving ball but fail".. is it frontal (movement), occipital (vision), or something else?  Hint: look up proprioception. 

Game board for matching lobes to functions

Even though the cerebrum has defined lobes and functions, one cannot just study a single region because brain cells are interconnected and can rewire themselves (neuroplasticity). For example, a stroke patient may be unable to speak, but with therapy the brain can wire new connections to undamaged areas so the person can relearn speech. To understand the process better, our focus switched to brain cells (neurons). 

‘Neuron’ by Casey L. Henley (CC-BY-NC-SA).
Credit: MSU Openbooks

Neurons can vary in size and shape, but have parts in common: cell body, axon (output), and dendrites (input). Dr. Aarron showed us cells using their digital microscope - we were delighted to learn it was homemade using OpenFlexure's microscope model. We also passed around slides, and he described how scientists prepare samples for labs using tools to make thin (40 micron) slices and dying them with H&E to color the nucleus purple and cell body pink.

It was time for a dissection demo! Dr. Natalia brought out sheep brain samples which had been preserved in formalin. Students could choose to handle the samples - those who did donned PPE (plastic coat, gloves). 

Before cutting, she pointed out the protective membrane (meninges) - when those were removed, we could see the folds that increase the surface area for grey matter cells. It was fascinating to compare the number of folds for a sheep brain compared to a mouse's brain which was smooth - animals have different folds, depending on complexity.  Also, both sheep and mice brains have comparatively large olfactory bulbs (nerves connecting from nose to brain)

Folds for sheep brain

Mouse brain has fewer folds

We also reviewed structures of the brain (cerebrum, cerebellum, brain stem, optic chiasm) and the lobes of the cerebrum since we could view the brain from the top (dorsal view) and below (ventral view). Dr. Natalia proceeded to cut the sheep brains in different ways (sagittal and coronal cuts). Students were asked to use pins to label major structures. 

Moving on, we learned about the connection between neurons. Information from one neuron's axon flows to another neuron's dendrites, but neurons aren't directly wired to each other. If all neurons were wired together and firing, that would actually cause a seizure. Instead, chemical neurotransmission occurs via: 

1. An axon converts its electrical signal to a chemical (neurotransmitter), which can be excitatory (e.g. glutamate), inhibitory (e.g. GABA), or modulatory (e.g. dopamine), and which is dumped into the space between the neurons (synaptic cleft)
2. Neurotransmitters drift across to the dendrite which converts the chemical signals to electrical. When received, ions from the brain flow into the neuron so the neuron builds up charge and fires a signal to the next neuron 

Neurotransmission is fast, about 20 milliseconds, but some neurons can send information faster because of myelin. To illustrate these, students were asked to run a relay race to pass a "secret" to another team member, with and without myelin. 

Running with myelin "booster"

The next activity demonstrated how neurotransmitters are cleared from the synapses by astrocytes. If this were not done, the remaining chemicals would interfere with neurons' receiving new messages.

What a mess!

Finally, students learned about inhibitory neurons - without them the brain would have a hard time distinguishing between a signal and noise from other neurons. The instructors brought a LED game to illustrate this principle - teams had fun challenging each other to stop the noise. 

That wrapped up the session - students had a lot to tell their parents that evening, and we are thankful to Drs. Aarron and Natalia for sharing about the fascinating world of neuroscience! 

Tips for other homeschoolers interested in organizing a class:

• Drs. Aarron and Natalia can be reached through the BioCompass Kids website or Instagram. They are also planning for future classes with different topics. 
• Our class size was capped at 12 students - this was an ideal number for discussion/interaction
• Plan for a large enough room (ideally with outdoor access) to accommodate all activities.