Overview
It has been claimed that the brain is the most complex system in the universe because there are more neuron connections in the brain than stars in our galaxy. Although this may be overly anthropocentric, the more than one trillion connections between neurons certainly is a compelling argument for the nearly inconceivable versatility, computational capacity, and memory retention of the human brain. In addition, the complexity of the synapses, which are the separations between neurons that convert the electrical signal to a chemical signal and back using neurotransmitters, further magnifies the potential power of the brain. The brain is a remarkable organ and the advances in knowledge pertaining to it over the past few decades have increased exponentially. Attempting to convey the scope of this knowledge is difficult, especially within the context of a unit intended for high school physics students. Therefore, focus on a particular, important element is necessary. In this unit, the creation, generation, and transmission of signals within a single neuron are discussed, to illustrate the implications of groups of neurons that do not fire properly, become synchronized, and result in epileptic seizures.
It is my goal to explain the requisite physics and chemistry to my students so that they can appreciate the awesome nature of neuron activity (not to mention the incredible nature of the intricate processes required to read this sentence!). I will describe the process of the transmission of a single impulse down a neuron and, to further engage the students, I will consider the broader context of groups of neurons and some of the implications when they do not fire as they are supposed to. Specifically, I will discuss the fact that the neuronal activity in the brain must be desynchronized and that synchronization of neurons can result in a seizure: chronic seizures are the condition known as epilepsy. Synchronization in brain signals (also referred to as entrainment) is the state when the neurons are firing systematically together, which is a malfunction of the brain that manifests as a loss of mental and/or physical control. This state is often witnessed as violent convulsions known as a seizure. Therefore, it is essential for normal brain function that the signals be desynchronized, or out of sync, otherwise, the recurrent condition can be debilitating and even deadly.
This unit is intended for mathematically advanced physics students. I will teach it to my first year gifted students as well as my second year, AP B physics students. This unit is challenging both at the conceptual and mathematical levels. However, I believe that these concepts can be simplified to teach it to all levels of physics students; perhaps, it would be of interest to chemistry teachers who would like to teach about the molecules involved in firing of a neuron.
My high school has approximately 1500 students with 450 of them being designated as gifted. The school is roughly 55% Caucasian and 40% African American and 5% other. There is a range of socioeconomic backgrounds as well, with approximately 30% of the students receiving free or reduced lunch. My classes are more homogeneous with a majority of Caucasian students, a lower percentage of African-American students and fewer economically disadvantaged students. However, next year all students will be required to take physics and all juniors are encouraged to consider taking a second year of physics.
Comments: