Author: Belinda Lin
Editors: Shannon Tan and Kira Tian
Artist: Kaitlyn Stanton
The brain contains billions of neurons all linked to one another, working crucial roles in mood, education, and interactions. But what exactly causes our ideas to surface? The answer lies in the receptors on the exteriors of the neurons.
Brain receptors are necessary for survival. Proteins composed of receptors are chemical structures, and they send signals that are received by neurotransmitters — first messenger— linked to biological systems from neuron to neuron. Each neuron has hardworking receptors on the surface which receive signals. The signals come in the form of chemical messengers that bind to receptors that later form cellular response. This changes the electrical activity of cells from adjacent neurons through neurotransmitters. Neurotransmitters are chemical messengers that transfer signals from one neuron to a target cell through the synapse. They help with communication in the brain. After the neurotransmitter molecule is received, it connects to the receptor of the receiving neuron. This is similar to what a lock and key system pertains, such that when a neurochemical (the key) binds with a neuron (the lock), the neurons react by continuing or stopping the signal. However, unlike the lock and key system, a neurotransmitter can bind with a variety of receptors. Receptors and neurotransmitters are fundamental in everyday life—without them, a person would die.
Although neurotransmitters contribute greatly to brain function, receptors also play a prominent role in brain function. Receptors can remodel the brain circuits, resulting in alternations in the different aspects of synapses, the small pockets of space between two cells. The alterations can be a change in the number or type of synapses. When looking at a synapse, hundreds of neurotransmitters are thrown and caught between cells.
Neurotransmitters are what activate receptors. Neurotransmitters might activate “second messengers”, enzymes that direct the cell to create more proteins or new ion channels, during this process. Ionotropic and metabotropic receptors are two major types of receptors. The difference is that ionotropic receptors form ion channel pores. Metabotropic receptors are secondary membrane receptors that use transduction mechanisms. They are composed of proteins known as G proteins; the G proteins first convert messenger chemicals to second messenger chemicals. Ionotropic receptors are fast working receptors, directing the cell to open or close their channels. When channels are opened, signals can then be sent to adjacent cells. When channels are closed, ionotropic receptors direct the cell to slow down or stop signaling.
Long term potentiation (LTP) is a molecular process that helps with learning and memorization. This process can be thought of as a continuity of rapid rounds of signal receiving; it increases enduring strength between neurons. However, there are specific neurochemicals that receptors need to receive to move forward with strength between neurons. There are two receptors involved in social bonding. The dopamine receptor, D2 receptor, helps with the formation of relationships. And D1 receptors are required to maintain that relationship. Receptors also control our analytical thoughts.
Neurotransmitters and receptors are one of the key components as to how the brain functions the way in which they do and how the brain circuits are wired!
Citations:
Penttila, Nicky. “How Do Brain Cells Communicate?” Dana Foundation, Dana Foundation,
29 Aug. 2019, www.dana.org/article/qa-neurotransmission-brain
“Receptor (Biochemistry).” Wikipedia, Wikimedia Foundation, 28 Aug. 2020,
en.wikipedia.org/wiki/Receptor_(biochemistry).