Class 4 - Animal Research - History of the Neuron Flashcards
Exam ques 100% =
How did we take 2 ideas (visualization + nerve impulse) and then neuroscience happen?
Or
How did visualization + nerve impulse lead to neuroscience?
Or
What was the impact of biological methods on neuroscience?
Consilience (the way in which we show how science builds on one another)….
Consilience means – that different areas of science connect and support each other. – It shows how new discoveries build on past knowledge.
Explain the attached image.
Around the 13th century, eyeglasses were invented to help people see better. – This led to the idea of the telescope. – Later, Robert Hooke experimented – with light and oil, – leading to the invention of the microscope. – Like Darwin’s theory of evolution, these discoveries opened new ways to study the world.
Why are we talking about microscopes? I thought this was about Neuron?
We discuss microscopes led to the discovery of cells, – which are essential to understanding neurons.
Robert Hook – coined the term “cells” – by noting that cork under the microscope looked like it had cells.
He created a book full of insects pictures called “micrographia” to share his discoveries with the world. – This new found term “micro world” sparked intense cursity.
Explain the attached image. Who was Anton Leeuwenhoek?
Anton Leeuwenhoek, who was a drapist, – invented – a powerful single-lens microscope to improve the way he wrapped drapes. – His microscope lense was much better than Hook’s – He made observations of his own
blood, skin, hair cells… among other things…– He drew the first images of red blood cells, protists, and spermatozoa.
Who invented microtome?
J.E Purkyne
Explain attached image.
The discovery of microorganisms sparked a scientific revolution, leading to a boom in microbiology. – Jan Evangelista Purkyne advanced the field by inventing the microtome, allowing thin tissue slices for detailed microscopic study.
He discovered heart has different cells (Purkinje fibers), showing that different cells have unique functions.
This pre-Darwin era focused on DESCRIBING cell types, fueling excitement in microbiology.
A scientific race began to explore the microscopic world, as more scientists gained access to microscopes.
Meanwhile, what did Europe embrace?
Romanticism
What did Romanticism, emphasized?
- Nature
- Individuality
- Harmony
Meanwhile, Europe embraced Romanticism, emphasizing nature, individuality, and harmony. – This shift inspired a new view of biology—seeing the body as a unified system, much like WHAT?
- As Darwin came up with Evolution.
- Newton transformed physics.
Explain the image.
A scientific race began to explore the microscopic world, as more scientists gained access to microscopes.
Meanwhile, Europe embraced Romanticism, emphasizing nature, individuality, and harmony. – This shift inspired a new view of biology—seeing the body as a unified system, much like how Darwin revolutionized Evolution or Newton transformed physics.
Explain image. don’t need to memorize these 1,2,3 points. Make sure you have an idea though as it connects to further slides.
Studying plant and animal cells – led to – Cell theory:
- All living things are made of one or more cells.
- The cell is the basic unit of life
- All cells come from pre-existing cells.
This raised questions – about how different cells function,– like why kidney and heart cells look and work differently.
What were the 2 major things that happened in neuroscience or what led to the emergence of neuroscience?
- Nerve Impulse
- Visualization
The timeline splits for a few years, then quickly comes back together when neuroscience begins.
Who challenged the idea that: nerve cells –worked together – because of supernatural forces, – not biology?
- Du Bois-Reymond
- Helmholtz
How did Du Bois-Reymond and Helmholtz challenge the following idea:
nerve cells worked together because of supernatural forces not biology?
They took a frog leg, – attached it to electrodes, – and sent an electrical impulse, – making the leg move. – Since this was the first time it was done, there was no standardization at that time. —- Later, they tested rapid stimulation – and noticed a delay before the leg moved again. – They thought the battery had died, – so they switched batteries which showed the nerve needed time to recover (refractory period).
They discovered that nerve impulses caused a drop – in electrical potential, which du Bois-Reymond called “negative variation“—now known as the action potential. – Helmholtz found that the impulse traveled at different speeds.
Before Du Bois-Reymond and Helmholtz WHO saw , frog leg react to electricity, but his work was dismissed because of unstable equipment before reliable batteries were invented?
Galvani
Explain the attached image.
Many people once believed – nerve cells –worked together – because of supernatural forces, – not biology. Du Bois-Reymond and Helmholtz challenged this idea.
They took a frog leg, – attached it to electrodes, – and sent an electrical impulse, – making the leg move. – Since this was the first time it was done, there was no standardization at that time. —- Later, they tested rapid stimulation – and noticed a delay before the leg moved again. – They thought the battery had died, – so they switched batteries which showed the nerve needed time to recover (refractory period).
They discovered that nerve impulses caused a drop – in electrical potential, which du Bois-Reymond called “negative variation“—now known as the action potential. – Helmholtz found that the impulse traveled at different speeds.
When was the first dye introduced and
who introduced it and
what was it called?
In 1820
by Turpin
called Carmine dye
What was the first dye used for?
To improve microscope contrast.
When was Hematoxylin dye, introduce and
who introduced it and
what did it enhance?
In 1865
by Böhmer
to enhance brain tissue visibility
Why did scientist use Contrast dye?
– Scientists used contrast dyes—one light to highlight unwanted tissue — and one dark to focus on key structures/elements–—making neurons easier to see.
What did the use of Contrast dye led to belief, yet what did other argue about?
That neurons formed a continuous network, —- but others argued – tiny gaps existed between them.
Explain the image.
Turpin (1820) first used Carmine dye to improve microscope contrast, later refined by Johann Diedrich. – In 1865, Böhmer introduced Hematoxylin dye, which enhanced brain tissue visibility. – Scientists used contrast dyes—one light to highlight unwanted tissue and one dark to focus on key structures—making neurons easier to see. – This led to the belief that neurons formed a continuous network, —- but others argued – tiny gaps existed between them.
Read the text.
This led to a long feud between Golgi and Ramón y Cajal, – with scientists taking sides.
Golgi’s theory seemed simpler and more intuitive, – while Cajal’s made things more complex.
Explain the image.
Julius Bernstein knew – Na+ and K+ – were in the body – and tested a frog leg – with a voltmeter. – When the leg was damaged, the reading turned negative, revealing that ions moved across the membrane. —- This confirmed electrical charges within the membrane as the basis for neural transmission.
