Long Term Potentiation and Memory Formation, Animation
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Long Term Potentiation and Memory Formation, Animation

The process of learning begins with sensory
signals being transcribed in the cortex. They are then transmitted to the hippocampus
where new memories are believed to form. If a signal is strong, or repeated, a long-term
memory is established and wired back to the cortex for storage. Lesions in the hippocampus impair formation
of new memories, but do not affect the older ones. The brain consists of billions of neurons. Neurons communicate with each other through
a space between them, called a synapse. A typical neuron can have thousands of synapses,
or connections, with other neurons. Together, they form extremely complex networks
that are responsible for all brain’s functions. Synaptic connections can change over time,
a phenomenon known as synaptic plasticity. Synaptic plasticity follows the “use it
or lose it” rule: frequently used synapses are strengthened while rarely used connections
are eliminated. Synaptic plasticity is believed to underlie
the process of learning and memory retention. New memories are formed when neurons establish
new connections, or STRENGTHEN existing synapses. If a memory is no longer needed or rarely
recalled, its corresponding synapses will slowly weaken and eventually disappear. The strength of a synapse is measured by the
level of excitability or responsiveness of the post-synaptic neuron in response to a
GIVEN stimulus from the pre-synaptic neuron. High-frequency signals or repeated stimulations
STRENGTHEN synaptic connections over time. This is known as long-term potentiation, or
LTP, and is thought to be the cellular basis of memory formation. LTP can occur at most excitatory synapses
all over the brain, but is best studied at the glutamate synapse of the hippocampus. When a glutamatergic neuron is stimulated,
action potentials travel down its axon and trigger the release of glutamate into the
synaptic cleft. Glutamate then binds to its receptors on the
post-synaptic neuron. The 2 main glutamate receptors that often
co-exist in a synapse are AMPA and NMDA receptors. These are ion channels that activate upon
binding to glutamate. When the pre-synaptic neuron is stimulated
by a WEAK signal, only a small amount of glutamate is released. Although both receptors are bound by the glutamate,
only AMPA is activated by weak stimulation. Sodium influx through the AMPA channel results
in a SLIGHT DE-polarization of the post-synaptic membrane. The NMDA channel remains closed because its
pore is blocked by magnesium ions. When the pre-synaptic neuron is stimulated
by a STRONG or REPEATING signal, a large amount of glutamate is released; the AMPA receptor
stays open for a longer time, admitting more sodium into the cell, thus resulting in a
GREATER DE-polarization. Increased influx of positive ions EXPELS magnesium
from the NMDA channel, which NOW activates, allowing not only sodium but also CALCIUM
into the cell. Calcium is the mediator of LTP induction. There are 2 distinct phases of LTP. In the early phase, calcium initiates signaling
pathways that activate several protein kinases. These kinases enhance synaptic communication
in 2 ways: they phosphorylate the existing AMPA receptors, thereby increasing AMPA conductance
to sodium; and help to bring more AMPA receptors from intracellular stores to the post-synaptic
membrane. This phase is thought to be the basis of short-term
memory, which lasts for several hours. In the late phase, NEW proteins are made and
gene expression is activated to further enhance the connection between the 2 neurons. These include newly synthesized AMPA receptors,
and expression of other proteins that are involved in the growth of NEW dendritic spines
and synaptic connections. The late phase may correlate with formation
of long-term memory.

56 thoughts on “Long Term Potentiation and Memory Formation, Animation

  1. wow great briefing about brain … I am too interested to learn about the brain functions however I have learn lots about it I even play security surveillance during learning which the brain parts of make me not to remember things in the shorts of time frames and why am I remembering everything from the past which is ages ago etc… then I put them side as my worst enemies the one doesn't do good for me and give special place the one did do good to me like long term memories as my friends. lol anyway thank u for great & powerful lessen.

  2. Can you explain how binatural beats effect your brain? Thanks for the great content, keep up the good work

  3. Thanks a lot, it is such a great and easy explanations. I have an exam withinn few days and your video helps me a lot.

  4. Excellent video! I also noticed that the activation of nitric oxide synthase by the protein kinases wasn't mentioned. Doesn't it have a role in LTP?

  5. Your vids are so clear & convincing ( perspicuous ) and condense so much info. that I can't wait for more vids on neuroanatomy. Call me !

  6. Help us make more videos like this! Support us on Patreon and get FREE downloads and other great rewards: patreon.com/AlilaMedicalMedia

    Thank you so much!

  7. If post synaptic bouton has excess sodium already, then how does more sodium and calcium enter into it, against concentration gradient? Is it an energy consuming process?

  8. oh my god that was just PERFECT !
    I have spent the past three months trying to understand LTP and STP with no hope.
    this explained everything. THANK YOU THANK YOU THANK YOU

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