Seeing Learning and Memory through the Microscope
Written by Shreyan Mitra
Modern neuroscience, despite being about 110 years old, is quite young compared to other fields of science. In 1906, Spanish neuroscientist, histologist, and pathologist Simon Ramón y Cajal collaborated with Italian biologist Camillo Golgi (the namesake of the Golgi Apparatus) in an attempt to study the structure of “brain cells” while making use of a technique for creating a color contrast between cellular components called Golgi staining. This effort earned the pair the 1906 Nobel Prize in Medicine, and Ramon y Cajal the title of “The Father of Modern Neuroscience”.
One major finding from the two was that the brain and what we know today as the Central and Peripheral Nervous Systems (CNS, PNS) are made up of billions of individual cells called “neurons”. Each neuron has four major parts. The dendrites receive information from other neurons. However, the dendrites themselves don’t do the receiving – that’s done by little structures called dendritic spines, which are prone to frequent change. Next up is the soma or the cell body. The axon and axon terminal pass the impulse along through a mechanism called saltatory conduction. The axon terminal transmits the signal to the next neuron’s dendrites across a gap called the synaptic cleft, and the cycle continues until the impulse reaches the desired location or is inhibited (or canceled).
The synaptic cleft is quite interesting, as it is perhaps one of the most flexible areas of neuronal growth. As we learn more and commit lessons to memory, we use some neuronal pathways (and therefore those synaptic clefts) more than others. We call this concept “synaptic plasticity”, the modification of players in the synaptic cleft under increased or decreased usage. Synaptic plasticity is so important in building memory and for a properly maturing nervous system that deficits in synaptic plasticity have been linked to Alzheimer’s disease, intellectual disabilities, autism, and schizophrenia. With such an important biological tool at its disposal, the cell has put it to use with an equally skillful operator – the AMPA receptor, or AMPAR.
To learn what role AMPA (a compound with a very long name) and its receptor play in memory-making, learning, and synaptic plasticity, we hosted a seminar on 9/19/2020 featuring Dr. Elena Lopez-Ortega. She also discussed microscopes and how we can use different types of microscopes to study neuronal cells, synapses, and receptors as they change as a result of synaptic plasticity.
Check out the recording to learn more about the evolution of microscope design, optical microscopes, confocal microscopes, fluorophores, and ways to make a sample easier to investigate. She also introduces software that you can use to try your hand at analyzing some specimen data!
November 2020 Course: