nurons Flashcards
Neurons
Neurons are nerve cells that enable the communication of information around the body. They do this by receiving, transmitting, and processing information in the form of neuronal messages (messages which can be sent via neurons).
Structure of the neuron
dendrites - receive aural messages
myelin - insulate the nuron and prevent disturbance from other nurons
axon terminal - sends neural messages to the next nuron
The synaptic gap
The synaptic gap is a tiny space between two neurons, where they communicate with each other. Nerves in the brain do not physically touch each other- they are separated by this ‘synaptic gap’
Neuronal messages are communicated at the synapse, which refers to the region that includes the axon terminals of the presynaptic neuron
The synapse
Refers to the entire junction between two neurons or between a neuron and a target cell, which includes the presynaptic terminal of one neuron and the postsynaptic cell. This is where neurotransmitters are released
neuroplasticity
The term neuroplasticity refers to the ability of the brain and other parts of the nervous system to change in response to experience. This includes the brains capacity to recover from or compensate for loss of function through injury.
The brain changes as a result of neuroplasticity is:
- Long-term potentiation- this refers to the strengthening of synaptic connections as a result of repeated activation.
- Long-term depression- this refers to the weakening of synaptic connections because of repeated low-level activation of certain synaptic connections.
Neuroplasticity occurs in response to two kinds of experience:
- Developmental plasticity
- Adaptive plasticity
Developmental plasticity
Developmental plasticity are changes in the brain that occur in response to ageing and maturation.
Synaptogenesis-
is the formation of synapses between neurons as axon terminals and dendrites grow.
Synaptic pruning-
the elimination of underused synapses. (as a result of LONG-TERM DEPRESSION)
Underused synapses are cut off, or ‘pruned’ to free up space in the brain and allow for the strengthening of frequently used synapses- this occurs throughout the lifespan but the periods which occur after infancy (ages two to three) and during adolescence and the most intense periods of synaptic pruning.
Myelination
is the formation and development of myelin around the axon of a neuron.
The axon a neuron becomes myelinated to facilitate more efficient communication of messages. This is done by protecting the neuron from interference from other neurons. This means that as we develop and learn new skills, communication in the brain can happen quickly and smoothly.
Adaptive plasticity
Adaptive plasticity enables the brain to recover from or compensate for lost function and/or to maximise remaining functions in the event of brain injury- rehabilitation after injury supports this process.
Sprouting-
Sprouting- the ability of a neuron to develop new branches on the dendrites or axons. This expands the reach of a neuron, particularly when the neuron has been damaged from the trauma, enabling new neural connections to be formed in areas of the brain where the neural activity has been prevented or depleted.
Rerouting-
is a neuron’s ability to form a new connection with another undamaged neuron. The neuron that is rerouting abandons its connection with a damaged neuron, enabling new neuronal connections to be formed after trauma and, by extension, cognitive functioning to be re-developed.
Critical periods
Critical periods refer to the rigid developmental period in which a specific function or skill must be learnt.