{"id":43583,"date":"2019-12-22T15:41:43","date_gmt":"2019-12-22T23:41:43","guid":{"rendered":"https:\/\/selfhacked.com\/?p=43583"},"modified":"2020-05-15T01:53:51","modified_gmt":"2020-05-15T08:53:51","slug":"long-term-potentiation-ltp","status":"publish","type":"post","link":"https:\/\/selfhacked.com\/blog\/long-term-potentiation-ltp\/","title":{"rendered":"What Is Long-Term Potentiation (LTP), And Why Is It Important?"},"content":{"rendered":"

Long-term potentiation<\/em>, or LTP, is one of the main mechanisms involved in synaptic plasticity. It occurs when the connections between neurons (synapses<\/em>) are \u201cstrengthened,\u201d which changes the way they interact with each other while processing information. Such changes to the brain\u2019s connectivity are some of the primary ways our brains learn and store new information. Read on to learn more about this process, why it\u2019s so important to cognitive functioning, and what kinds of lifestyle and health factors can impair the brain\u2019s ability to carry out this important function!<\/p>\n

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Long-Term Potentiation: A Basic Overview<\/strong><\/span><\/h2>\n

The human brain is comprised of 100 billion neurons, each of which connects to up to 10,000 other brain cells through small \u201cgaps\u201d or \u201cjunctions\u201d called synapses<\/em>.<\/p>\n

Our brains incorporate and store new information – such as skills or memories – by adjusting both where<\/em> and how<\/em> different individual neurons connect and \u201ctalk\u201d to each other.<\/strong> This ability to change and adapt how neurons connect to each other – and thus alter how they process and store information – is referred to as synaptic plasticity<\/em><\/strong><\/a>.<\/p>\n

\u201cSynaptic plasticity\u201d is a general process that can take many forms.<\/strong> For example, it may refer to the \u201cstrengthening\u201d or \u201cweakening\u201d of individual neuronal connections at existing synapses. Alternatively, it can also refer to the creation of entirely new<\/em> connections between formerly-unconnected brain cells (a process called synaptogenesis<\/em>).<\/p>\n

Long-term potentiation<\/em> – or just \u201cLTP\u201d for short – is one of the most important processes involved in synaptic plasticity at existing neural synapses.<\/strong> Specifically, it means that the existing connection between two brain cells is strengthened<\/em>, thereby making it easier for these two neurons to stimulate each other when the other is activated. This is one of the main mechanisms involved in how we store long-term memories or learn new information and skills [R<\/a>, R<\/a>].<\/p>\n

LTP occurs when two different neurons are stimulated – a role that is often (though not always) carried out by the neurotransmitter glutamate<\/em><\/a>. Glutamate is the main \u201cexcitatory\u201d neurotransmitter in the brain, and contributes significantly to the formation of memories and learning [R<\/a>].<\/p>\n

When two neurons repeatedly \u201cfire\u201d together, they become sensitized, and more responsive to stimulation by each other.<\/strong> It\u2019s almost as if the neurons \u201cremember\u201d that they were previously stimulated, and they become easier to activate. This increase in excitability can last anywhere from hours to days. The synapse is therefore said to be stronger because it can carry impulses easier [R<\/a>, R<\/a>].<\/p>\n

LTP was originally discovered in the hippocampus<\/em>, a part of the brain that is believed to be heavily involved in learning and memory, spatial navigation, and emotion. Neurons from the hippocampus connect with neurons of the amygdala<\/em>, one of the main brain areas responsible for processing emotions. This may be why certain memories make you feel happy or sad [R<\/a>, R<\/a>].<\/p>\n

However, LTP has also been observed throughout many other regions of the brain, including the cerebellum, cerebral cortex, amygdala, and hippocampus [R<\/a>].<\/p>\n

Long-Term Potentiation Requires Maintenance<\/strong><\/span><\/h3>\n

LTP typically occurs in three main steps<\/strong> [R<\/a>]:<\/strong><\/p>\n

    \n
  1. The \u201cinduction\u201d phase<\/strong><\/li>\n
  2. The \u201cexpression\u201d phase<\/strong><\/li>\n
  3. The \u201cmaintenance\u201d phase<\/strong><\/li>\n<\/ol>\n

    The first two steps – \u201cinduction<\/em>\u201d and \u201cexpression<\/em>\u201d – are the initial stages of LTP. They correlate to short-term memories. They happen when you learn something new, like perhaps during a lecture. This is the beginning of long-term potentiation.<\/p>\n

    However, without the third step – \u201cmaintenance<\/em>\u201d – you probably wouldn\u2019t be able to recall this information later on.<\/p>\n

    When you \u201crehearse\u201d new memories or information – such as by sitting at home and studying new information – over time these new neural pathways are re-activated again, and the memories become more stable (\u201cconsolidated<\/em>\u201d). This occurs because of increases in proteins that will actually change the shape of neurons to accommodate the information. This is the process of maintenance<\/em> – and it allows us to store information for years at a time within a single neuronal pathway [R<\/a>].<\/p>\n

    How LTP Works<\/strong><\/span><\/h3>\n

    NMDA-receptor dependent LTP is the most well-researched form of long-term potentiation. This is how it works [R<\/a>]:<\/p>\n

    LTP occurs in two main phases, which could be thought of as the \u201clearning\u201d process and then the \u201cmemory-consolidation\u201d process.<\/p>\n

    Early-Phase LTP (\u201clearning\u201d):<\/strong><\/p>\n