Lecture 4 - Neuroscience Basics Flashcards

Question

what are some brain regions involved in memory?

Answer 1

basal ganglia amygdala thalamus hippocampus Many of these are “subcortical” This image makes it hard to see; go back to your 3D anatomy! If we were to peel away the cortext and look under the hood we would see the regions we commonly refer to as subcortical - For example the basal ganglie which is a collection of nuclei - these are the regions you would be able to see if you were to peel off the outer layer of the brain (we would see the basal ganglia, thalamus, amygdala, hippocampus)

Answer 2

Brain and spinal cord make up the “central nervous system” Brains are also connected to the rest of the body - the brain and spinal cord make up the central nervous system

Answer 3

The “central nervous system” connects to the body (organs, muscles) (peripheral nervous system) Organs and mussles of the body Central nervous system is the brain and spinal cord and it is connected to the rest of the body (organs and muscles) which is the peripheral nervous system

Answer 4

What is it made of? ○ (1) Close to 100 billion neurons (We have LOTS of different neurons in the brain) ○ (2) Other types of cells (numerous) (The brain is made of other types of cells) ○ (3) Blood vessels (brain has blood vessles - so it is not just neurons, lots of other stuff) Know what a textbook neuron looks like? Neurons are split into different parts: - dendrites - cell body - axon

Answer 5

The prototypical neuron has three main parts: * Dendrites are input areas that receive signals from other neurons * The cell body integrates signals from the dendrites * One or more axons, which transmit signals to other neurons (the reason axons can transmit signals very quickly is because they are covered in this fatty substance called mylien seath)

Answer 6

Glia: cells of various types. They provide functional or structural support to neurons. Some contribute to changes in connections between neurons ○ Astrocytes line the outer surface of blood vessels (in the brain) ○ Oligodendrocytes wrap the axons in myelin, a fatty substance that insulates electrical signals transmitted by neurons (they have a different name outside of the brain) ○ Does glia have other functions? More evidence is needed.

Answer 7

Blood vessels are like spider webs wrapped around the brain and is in the inner parts of the brain - we have the outer surface - blood vessles continue through the inner portions of the brain. This is because blood vessels are very important in suppyling nutrients to different parts of the brain. And when there is blockage of blood flow there can be catatrophic concequences

Answer 8

Neurons communicate in the synapse There is some input from the environmet (such as seeing a flickering light on the screen, hearing your professor speak) this will lead to the firing of neurons and there will be a signal that transmits across those neruons, but how does that happen? If you zoom in on the neurons you will see that there is a space between a presynapatic neuron and post synaptic neuron - the space is called the synapse (the neurons do not actually touch each other) - this is important for understanding how neurons are actually commincating with one another

Answer 9

Synapse –specialized for chemical communication between axon and dendrite, where the two cells draw very close but do not quite touch (The presynaptic and post synatic neurons are very close to one another but they do not touch) ● Presynaptic side – The axon has vesicles loaded with neurotransmitters. (The presynaptic side is the axon that has vesicles that are loaded with neurotransmitters) ● Postsynaptic side – The dendrite is lined with receptors to detect the neurotransmitter. (The postsynpatic side is the dendrite which is lined with recptors that are waiting to reicve neurotransmitters ) The presynpatic neuron is going to release neurotransmitters (we call this chemical transmission because it is a chemical being released) and that is going to bind to the posysyaptic neuron aand that is how the neurons are going to talk to one another

Answer 10

Ramón y Cajal is important for pointing out that neurons do not touch; neurons are individual units

Answer 11

● Neurons contain neurotransmitters, chemical substances that can cross a synapse to affect the activity of a nearby (postsynaptic) neuron ● Several different chemicals act as neurotransmitters ○ Glutamate, gamma-aminobutyric acid (GABA), acetylcholine, dopamine, norepinephrine, epinephrine, and serotonin ● Receptors are molecules embedded in the surface of the postsynaptic neuron. They are specialized to bind with and respond to certain neurotransmitters (like a lock and key) Receptors are only senstitive to certain neurotransmitters - only certain keys are going to open up the lock

Answer 12

● Some neurotransmitters—glutamate, for example—are excitatory. They activate receptors that tend to increase the likelihood of the postsynaptic neuron firing. ● Other neurotransmitters— such as GABA—are inhibitory. They activate receptors that tend to decrease the likelihood of the postsynaptic neuron firing.

Answer 13

● Neuromodulator: a neurotransmitter that modulates activity in a large number of neurons rather than at a single synapse. ○ Example: Dopamine Some neurotransmitters are reffered to as Neuromodulators - instead of acting on one postsynpatic neuron they actually mogulate the activity of a large number of neurons. So rather than one single synapse multiple synapses - Ex: Dopamine.

Answer 14

● When an action potential occurs, there is a lot of stuff happening ○ Calcium enters the cell and that triggers neurotransmission ○ Neurotransmission, in turn, can spur an action potential ● Neuronal communication is electrical AND chemical! (When we talk about action potentials and neurons firing we are talking about something that is electrical in nature. The eletrcial signal is something that is being probegated down those axons. What is happening at the synpase is chemical)

Answer 15

● Learning and memory researchers have focused almost exclusively on understanding the the ability of synapses to change as a result of experience (synaptic plasticity) (Learning and memory researchers have focused a lot at what happens at the place of the synapse. Is there something that changes about the way neurons are talking to each other (this is often referred to as synaptic plasticity)) ● “Hebbian learning”: any physical change in neurons can affect neural communication, that is, the connections between neurons (Hebbian learning - any physical change that happens at the level of the neuron can affect the way that the neurons are talking to each other) ○ Learning that involves strengthening connections between neurons that work together (Hebbian learning referrs to learning invovles the strengthening of connects between neurons together - somethinng about their relationship strengthens) ● These ideas were more hypothetical at the time of Donald Hebb (strong evidence came later) ● “Neurons that fire together wire together” (important thing you need to remember from Donald Hebb is “neurons that fire together wire together” - something about the wiring of the nervous system changes as a result of expirence)

Answer 16

Measuring Neural Patterns Due to Learning ● Long-term potentiation (LTP): a process in which synaptic transmission (between neurons) becomes more effective as a result of recent, repeated activity (The instation of the idea that neurons that fire together wire together) ● LTP is believed to represent a type of synaptic plasticity, which could be a neural mechanism for learning

Answer 17

(In this picture we have a presyanaptic and postsynpatic neuron with a synpase between them. It has a stimulating electrode that is going to stimulate that presynpatic neuron and a recording electrode that is going to record activity of that post synpatic neuron - you are stimulating the axon and then you are recording from the dendrite) (A) Researchers used an electrode to stimulate the axons of presynaptic neurons. A second electrode was used to record the activity of postsynaptic neurons. (B) Initially, weak stimulation caused only a mild response in the postsynaptic neuron. But after a burst of high-frequency stimulation, the postsynaptic neuron responded more strongly to the weaker stimulation and this persisted. (This is the key part - you weakly stimulate the neuron you get a weak response - you follow that with a high frequency stimulation and then after when you stimulate that neuron again but only weakly as you did initally you aare going to get a higher resonse ^- the neuron has been petentuated, it is more senstitive to a weak stimulation after it has been stimulated very heavily)