\u201cSynaptic plasticity\u201d refers to the process that the brain uses to adjust how neurons connect to each other and process information. This process is extremely important for all forms of learning and memory, since the only way the brain can store new information is to change its own structure! Plasticity is also extremely important to the brain\u2019s ability to recover from stress or damage, and is currently believed to play a major role in many different neurological and psychiatric disorders. Read on to learn more about plasticity, how it works, and why it\u2019s so important!<\/p>\n
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It was once believed that the brain is extremely fragile, and that any damage to it is more or less permanent. This would mean that if a person\u2019s brain was damaged or failed to develop properly in the first place, they were fated to live with it permanently!<\/p>\n
<\/a>However, the discovery of synaptic plasticity<\/em><\/strong> in 1966 overturned that belief. This gave new hope<\/a> to people with brain damage, neurological diseases, or learning disabilities [R<\/a>].<\/p>\n <\/a>In fact, the brain is a lot more flexible and resilient than we previously thought! Neurons can re-grow and new neuronal connections can be made. This actually allows us to learn new skills and memories in everyday life since the brain is a physical organ, and therefore, has to change its structure in order to store any new information.<\/p>\n <\/a>Synaptic plasticity is our brain\u2019s key to the formation of new memories and neural networks – especially within the hippocampus, a brain structure that is believed to be heavily involved in memory.<\/p>\n <\/a>Furthermore, neural plasticity may also be involved in repairing the brain from damage, such as from head traumas, stress<\/a>, toxins, or even a lifetime of poor diet and lifestyle choices.<\/p>\n Scientists currently estimate that our brain contains approximately 100 billion neurons.<\/strong> These neurons communicate with one another by forming synapses<\/em><\/strong>, which is the place where two neurons meet and connect.<\/p>\n However, this connection doesn\u2019t involve direct physical contact, as it would on a circuit board, for example. Instead, each \u201csynapse\u201d is actually a tiny gap in between where the two neurons meet. This is where one neuron releases chemicals (neurotransmitters<\/em>) in order to trigger an electrical response in the neighboring neuron.<\/p>\n By connecting into a series of synapses, this is how individual brain cells form signaling pathways, or \u201ccircuits\u201d, which allows them to pass along and process information.<\/p>\n Synaptic plasticity<\/em><\/strong> refers to our brain\u2019s ability to adjust the connections between neurons, which changes how they communicate with each other and process information. This process can be accomplished either by creating an entirely new synapse, or by adjusting the \u201cstrength\u201d of an existing synapse [R<\/a>].<\/p>\n When an existing synaptic connection is strengthened, this is called long-term potentiation<\/em><\/strong><\/a> (LTP)<\/strong>. Conversely, when a connection is made weaker, this is called long-term depression<\/em> (LTD)<\/strong>.<\/p>\n Technically, \u201csynaptic plasticity\u201d refers only to changes that occur in the connections between neurons. However, you might also hear the term \u201cneuronal plasticity<\/em>,\u201d<\/strong> which is a broader concept that includes synaptic plasticity as well as other biological changes to the brain, such as the creation of entirely new neurons (a process called neurogenesis<\/em><\/strong><\/a>).<\/p>\n Each of these processes is critical for a person\u2019s ability to learn and store new information of all kinds!<\/strong> In other words, whether we\u2019re talking about learning new motor skills (such as learning how to ride a bike) or if we\u2019re talking about learning a new fact or forming a new memory, all of these abilities depend on the brain\u2019s ability to adjust the way its cells connect to each other and process information.<\/p>\n Glutamate<\/a> is believed to be one of the most important neurotransmitters involved in synaptic plasticity [R<\/a>].<\/p>\n Glutamate receptors that are involved include \u201cAMPA\u201d (hydroxy-3-methyl-4-isoxazole propionic acid<\/em>) and \u201cNMDA\u201d (N-methyl d-aspartate<\/em>) receptors.<\/p>\n Therefore, glutamate plays a key role in learning and memory.<\/p>\n Because glutamate is an excitatory<\/em> neurotransmitter, it may be specifically related to long-term potentiation<\/em><\/a> (LTP), which is the part of synaptic plasticity that refers to the strengthening of existing neural connections.<\/p>\n However, glutamate is far from the only critical factor! For example, many of the other major neurotransmitters – such as acetylcholine and other choline<\/a>-based neurotransmitters – are also believed to be important for synaptic plasticity. There are also many other critical factors beyond just neurotransmitters, such as growth factors<\/em> (\u201ctrophic factors<\/em>\u201d), which stimulate the brain into creating new neurons and synapses [R<\/a>].<\/p>\n Intrinsic brain plasticity<\/em>, or the brain\u2019s inherent ability to rewire itself, is an important and evolutionarily conserved neural correlate of all forms of learning [R<\/a>].<\/p>\n Intrinsic plasticity is also an important predictor of learning-induced behavioral plasticity [R<\/a>].<\/p>\n Synaptic plasticity allows for long-term potentiation – or increasing the strength of our synapses with more use, which allows us to memorize or become fluent at the things we learn. Therefore, synaptic plasticity is essential for learning and memory [R<\/a>].<\/p>\n Located in the medial temporal lobe, the hippocampus plays a key role in forming new associations and consolidating stimuli into new memories [R<\/a>].<\/p>\n Specialized cells in the hippocampus can also undergo cell division (mitosis<\/em>) to generate entirely new brain cells (neurogenesis<\/em>) [R<\/a>]. Synaptic plasticity is important for these cells to integrate with other hippocampal cells.<\/p>\n Neuroplasticity is what allows the central nervous system to (partially) recover from damage, such as brain injuries. In addition, the brain can adapt through secondary compensatory mechanisms when there is some brain tissue damage [R<\/a>].<\/p>\n Some preliminary research suggests that long-lasting morphological changes occur in the hippocampus after traumatic brain injury – including the growth of cell bodies (soma<\/em>) and recruitment of new neurons into the hippocampus [R<\/a>, R<\/a>].<\/p>\n Spinal injuries that damage the sensorimotor pathways are known to cause synaptic changes in neuronal circuitry, within the spinal cord and at higher levels, over the postinjury weeks and months [R<\/a>].<\/p>\n<\/a>What is a Synapse?<\/strong><\/span><\/h3>\n
<\/a>Glutamatergic System and Synaptic plasticity<\/strong><\/span><\/h2>\n
<\/a>Why is Synaptic Plasticity Important?<\/span><\/h2>\n
<\/a>1) Synaptic Plasticity is Important for Learning and Memory<\/span><\/h3>\n
<\/a>The Role of Synaptic Plasticity in The Hippocampus (Memory Center) <\/strong><\/h4>\n
<\/a>2) Synaptic Plasticity Helps Recover from Brain and Nervous System Injuries<\/strong><\/span><\/h3>\n