13 How neurons communicate
Summary
TLDRThe lecture explains how neurons communicate through an electrical process, focusing on the concept of action potentials. It discusses the threshold needed for neurons to fire and transmit information to other neurons via synapses. The analogy of firing a gun is used to explain the 'all-or-none' law, where neurons either fire completely or not at all. It also introduces the 'refractory period,' a rest phase after firing, during which the neuron cannot fire again. A more detailed video on Canvas is recommended for further learning.
Takeaways
- β‘ Neurons communicate information via an electrical process, but the actual messengers are chemicals called neurotransmitters.
- π§ The transmission of information between neurons occurs when an electrical impulse triggers the release of neurotransmitters.
- π A neuron at rest is in its 'resting potential,' which means it isn't being stimulated.
- π¦ The 'threshold' is a critical membrane potential that must be reached for an action potential (electrical impulse) to occur.
- π« The 'all or none law' states that a neuron either fires completely or doesn't fire at all, similar to firing a gun.
- π Once the threshold is reached, an action potential travels down the axon and triggers the release of neurotransmitters into the synapse.
- β³ After firing, neurons enter the 'absolute refractory period,' during which they cannot fire again for a brief period.
- π The refractory period prevents neurons from continuously firing and forces them to have a break before they can fire again.
- π After the refractory period, the neuron returns to its resting potential and can fire again if the right conditions are met.
- π½οΈ A more detailed video on this process, including action potentials, is available on Canvas for additional learning.
Q & A
What is the main process by which neurons communicate information?
-Neurons communicate information through an electrical process, though the actual messengers involved are chemicals.
What is the resting potential in a neuron?
-The resting potential is the baseline electrical state of a neuron when it is not being stimulated or transmitting information.
What is the threshold in neuronal communication?
-The threshold is the membrane potential required to trigger an action potential. It is a critical level that must be reached for the neuron to transmit information.
What happens if the neuron doesn't reach the threshold?
-If the neuron doesn't reach the threshold, no action potential occurs, and the neuron returns to its resting potential.
What is an action potential?
-An action potential is an electrical impulse that travels down the axon of a neuron, triggering the release of neurotransmitters into the synapse.
What is the 'all or none' law in neuronal firing?
-The 'all or none' law states that a neuron either fires completely or does not fire at all; there is no partial firing.
What is the absolute refractory period?
-The absolute refractory period is the time after an action potential during which the neuron cannot fire another action potential, allowing the neuron to rest.
Why is the refractory period important in neuronal communication?
-The refractory period prevents continuous firing of neurons, allowing them to rest and preventing overstimulation. It limits the maximum firing rate of a neuron.
What role do dendrites play in neuronal communication?
-Dendrites receive neurotransmitters from neighboring neurons if they have the proper receptors, facilitating the continuation of communication between neurons.
What does the video on Canvas cover in more detail?
-The video on Canvas covers the process of action potentials in more detail, offering additional insights beyond the lecture's content.
Outlines
π§ Understanding Neuron Communication
This paragraph introduces how neurons communicate information through an electrical process, even though the messengers are chemical. It describes the process as a mix of electrical and chemical transmissions, where neurons must reach a threshold to fire and transmit information across the synapse. The concept of resting potential, threshold, and action potential is explained, including failed attempts to reach the threshold and how the successful triggering of an action potential results in neurotransmitter release. The 'all-or-none' law is highlighted, stating that a neuron either fully fires or it doesn't at all. Finally, the concept of refractory periods is introduced, which limits how often neurons can fire.
π‘ The Importance of Refractory Periods
This paragraph dives deeper into the refractory period, a resting phase where neurons cannot fire again immediately after an action potential. The refractory period limits the firing rate of neurons, preventing continuous, unchecked firing. This provides neurons with necessary breaks before another action potential can occur. The paragraph concludes by encouraging viewers to watch a more detailed video on action potentials and reminds them that the next lecture will continue to explore this topic further.
Mindmap
Keywords
π‘Neuron
π‘Axon
π‘Dendrite
π‘Action Potential
π‘Resting Potential
π‘Threshold
π‘Synapse
π‘Neurotransmitter
π‘All or None Law
π‘Absolute Refractory Period
Highlights
Neurons communicate through a combination of electrical and chemical processes.
The transmission of information between neurons is primarily an electrical process.
Neurons have a resting potential when they are not being stimulated.
For a neuron to transmit information, it must reach a critical threshold called the 'membrane potential.'
When the threshold is met, an action potential occurs, triggering the neuron to fire.
The action potential is an electrical impulse that travels down the axon.
Action potentials lead to the release of neurotransmitters into the synapse.
The 'all or none law' states that a neuron either fires completely or not at all.
A neuron cannot partially fire; it's either fully activated or it remains inactive.
After an action potential, the neuron enters the absolute refractory period, where it cannot fire again.
The absolute refractory period acts as a rest phase, limiting the neuron's firing rate.
The neuron eventually returns to its resting potential, ready to fire again if stimulated.
Refractory periods are essential for preventing continuous firing of neurons.
The video on Canvas provides a detailed explanation of the action potential process.
This lecture emphasizes the importance of understanding electrical impulses and thresholds in neuron communication.
Transcripts
so now that we know what axons and
dendroides are we need to talk about how
neurons actually communicate this
information so I already said that
basically it's a electrical process in
terms of how this actually happens the
actual Messengers themselves are
chemicals but the way everything is
transmitted from one neur to another is
through an electrical process so there
are things we need to go over with all
this and I do have a video on canvas
that will go over this whole process in
a little bit more detail then how I'm
going to go over it I figure it doesn't
hurt to have an extra rendition of this
material because it is a little
confusing so essentially what happens is
like I said we have this whole
electrical process but this isn't a
continuous process certain things have
to happen in order for one on to to
transmit that information into the
synapse so if we were to actually graph
everything
out this is this whole communication
process and what happens when basically
one neuron fires and you know takes that
information and releases it into the
synapse so another neur can pick it up
so here we have what's known as our
resting potential this is basically what
the neuron is set at when it's not being
stimulated and then there's this very
light gray line right here this is the
threshold the threshold is this membrane
potential that's necessary in order to
trigger an action
potential so basically it's this
critical level that's needed for an
action potential to happen an action
potential is that actual electrical
trigger of this uh neuron so it's you
know this electrical trigger of this
information in this neuron it's
basically going to force this neuron to
transmit this
information so here we have a few
attempts where the San you know tried to
hit that actual threshold but did not
and as you can see here nothing happened
it basically went back to that resting
potential but in this case we're
following this red
line we actually do hit that threshold
we hit that point where it's possible
for an action potential to happen it's
this critical level that's needed so an
action potential is this electrical
impulse that travels down the
axon and what it does is it triggers the
release of those neurotransmitters we'll
talk about neurotransmitters soon into
the synapse and then other neurons near
by can pick up those
neurotransmitters if they have the
proper uh let's just say situation
because it's very specific how this
happens through their
dendrites now an action potential is
similar to like firing a gun either you
fire the gun or you
don't so there's something known as the
all or none law it's basically this
whole idea that either a neuron fires or
it
doesn't so in this case looking at this
curve the neuron fired but in these
situations it did not so you can't have
a situation where the neuron you know
half fires the information or anything
like that either it fires the
information or it
doesn't
now this whole process I'm trying to
find my cursor this whole process is
showing the neuron actually firing that
information it's that whole electrical
impulse but then as you can see here it
doesn't return to normal it doesn't
return to that resting potential it
actually goes under a little
bit this whole area
Here is known as the absolute refractory
period s referred to as a refractory
period just depends on you know which
person is teaching the information this
is a period after an action potential in
which another action potential cannot be
triggered
it's essentially a rest period for this
neuron and then as you can see the
neuron then goes back to that resting
potential here and another action
potential could take place if the
certain sit or certain circumstances
have been met so there's certain things
that have to be met in order to get to
that threshold part like said the video
that I'm going to post on canvas goes
over this in a little bit more detail in
some ways it goes over more detail than
you need to know but it'll go over a
little bit more
detail so basically what happens in the
absolute refractory period is the neuron
cannot fire again and this rest period
really limits the maximum firing rate of
the neuron which really could be a good
thing it gives this situation where you
know you can't have a neuron just
continuously firing this
information it has to have a little of a
break
so it actually it's a good thing and
then I'll go back to that resting
potential and then you know if the
neuron's able to hit that threshold
another action potential can
occur so that's all I'm going to say in
this lecture video like I said there is
another video on canvas that goes into
an action potential specifically so
definitely take a look at that
especially if you are kind of new to
this information or it's been a while um
and I will see you in the next lecture
video where we'll continue talking about
this whole
process
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