The Basics of Neuroplasticity Flashcards
What is the Hebb theory about neuronal networks?
If neurons are connected, and activated together, their chances of forming a cohesive network that will remain activating is higher. Essentially, neurons that wire together, fire together.
What drives neuronal changes?
Nature and nurture (genes and the environment).
Our individual genetic code drives the basic structure and process of our brain developments, however, our life experiences drive neuroplasticity and brain adaptation to maximize our survival.
When do most of the “hard wiring” occur?
From birth and throughout adolescence.
What are the three stages of synaptic growth?
growth –> peak –> pruning.
What happens when we reach the peak stage?
There is a great number of synapses, but the quality of those connections is weak.
What is synaptic pruning?
Synaptic pruning removes weak synapses and leaves the main and important connections. This allows for better quality connections.
Does the brain mature as one homogenous unit?
No, it happens in different areas at different times. It matures from bottom to top, and back to front.
When does neuroplasticity happen during the lifespan?
The first wave occurs during childhood and adolescence. The second wave occurs due to the maturation of the prefrontal cortex, which happens during your 20’s.
Why do brain systems mature at different times?
Maturation depends on survival urgency (survival needs), phylogenetically (older brain areas mature first), and complexity (hierarchy of integration).
What enviornmental factors impact brain development?
Psychoactive drugs, gonadal hormones, parent-child relationships, peer relationships, stress, diet, intestinal flora, and sensory/motor experience.
what does experience-expectant plasticity refer to?
When an infant’s brain is developing, it expects certain external inputs to aid in the development of neural connections, brain systems, and basic skills.
These include visual cues, hearing, emotional development, language, higher cognitive functions etc.
What happens if experience-expectant plasticity does not occur?
If the infant does not receive input during these critical periods, these functions will not develop properly and can be lost forever.
What is experience-dependent plasticity?
This type of plasticity refers to the continuous process of the creation and organization of neuron connections driven by individual life experiences.
What did the rat study tell us about experience-dependent plasticity?
Rats that were provided an enriched environment had increased the development of dendrites and synaptic connections. In a deprived environment, the plasticity period is shortened and can result in underdeveloped systems.
what is epigenetics?
Epigenetics is another factor that affects neuroplasticity. The environment can change the expression of a gene, without changing the genomic sequence.
what does methylation do?
It switches off gene expression.
What does acetylation do?
It switches on gene expression.
What are the three stages you go through after suffering a brain injury?
Cell dysfunction, cell genesis, and adaptive plasticity.
What happens during cell dysfunction?
Cell death, edema (swelling due to trapped fluid in tissue), metabolic depression, and axonal growth inhibition.
What does cell death cause?
A decrease in cortical inhibitory pathways, which results in the recruitment of secondary neuronal networks.
Swelling occurs dues to trapped fluid in tissue.
What occurs during cell genesis?
Gliogenesis, neurogenesis, angiogenesis (new blood vessel formation).
Neuronal proliferation and synaptogenesis occur. Neuronal and non-neural cells are recruited to replace damaged cells.
What occurs during adaptive plasticity?
Axonal sprouting, synaptogenesis, functional plasticity, and network re-learning.
