Neuroplasticity

Nature (genetics)

Provides layout of the nervous system

Nurture (environment and experience)

Various connections are adjusted to meet demands of environment, also known as nueroplasticity

Neuroplasticity

The ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure functions and connections

Critical periods of nueroplasticity

Early development

Ongoing adjestments

Learning and memo more, constraint induced movement therapy, etc

Synaptic efficiency changes

Connections change in strength based on use, neuronal pathways are created by signals (neurotransmitters) passing from one neuron to the next at synapses

Potentiation

The more we think or do something, the more efficient the synapses become and its easier to do or remember something (an increase in synaptic efficiency)

Depression

The less we do or think something, the less efficeient the synapses become and the harder

Hebb's principle

Neurons that wire together fire together, neurons that wire apart fire apart

Short term potentiation (STP) or depression (STD)

Lasts a few minutes, general consequences of activity

Long-term potentiation (LTP) or depression (LTD)

Produces lasting changes (hour to years), basis of learning and memory AND what we hope to affect in neurorehab

Unmasking

Revealing existing, but rarely used, neuronal pathways

Synaptogenesis

Creating of new synapses

Axonal sprouting

Creation of new axonal branches

Structural growth ("re-wiring")

Creating new neuronal connections and pathways through synaptogenisis and axonal sprouting

nuerogenesis

New nuerons are generated and integrated into e

Neuronal stem cells

cells that can produce new CNS neurons or glial cells, found in walls of ventricles (remain latent), hippocampus (produce new cells), subventricular zone of lateral ventral to migrate to olfactory bub

cortical re-organization

Functional reassignment

Facilitators of Nueroplasticity

intensity and repetition, specificity, salience, active engagement, progressive challenge, novelty and enrichment, feedback and reward, transfer to real life, excersise, sleep, and recovery

Prenatal neurological development

neurons and the connections between them are produced in excess

matching process

infants must then match neuronal connections to their body and external environment though this, includes dying off surplus neurons and retracting inappropriate connections

Neurotrophic factors

target tissues in the body produce a limited quantities of nerve growth factor and brain derived neurotrophic factors, where these factors can transport them retrogradely to neuronal cell bodies to nourish the cell and allow it to survive

Neuronal Competition

neurons compete for neurotrophic factors during development

Immature neurons

receive inputs and make synaptic connections much more easily than mature nuerons

critical periods

plasticity is maximal and synapses made during critical periods are more or less permanent, vary in length for different parts of the brain and different skills, allow acquisition of complex skills such as language and visual discrimination

declarative (explicit) memory

memory of facts, events, concepts, places

nondeclarative (implicit) memory

procedural memory, classical conditioning, priming, "muscle" memory

immediate memory

lasts up to 3 seconds, snapshot of sensory input, processed by primary sensory and sensory association areas of brain and is encoded for the next stage

working memory

last 3-30 seconds, information we "keep in mind", manipulate and rehearse

long term memory

lasts more than 30 seconds to remote, relatively permanent storage of information that has, conversion of working memory to long term memory

Consolodation

conversion of working memory to long

cerebral cortex

stores long term memory in this information in diffuses neuronal networks, interconnected by synapses

Hippocampus

a curved area of cortex that lies in the limbic lobe, submerged in the parahippocampus gyrus

HM case

His hippocampus was removed, he wasn't able to create new memories

retrograde amnesia

loss of memory from the point of some injury or trauma backwards, or loss of memory for the past

anterograde amnesia

deficit in forming new memories

3 types of nondeclaritive memory

skills and habits, emotional associations, conditional reflexs

basal ganglia, cerebellum, neocortex

where skills and habits occur

amygdala

where emotional associations occur

cerebellum

where conditioned reflexes occur

3 stages of motor learning

cognitive, associative, autonomous

Cognitive Stage

the stage in motor learning where one verbally guides motor tasks, which requires a lot of attention

Associative Stage

the stage in motor learning where movement is refined and made more efficient

Autonomous Stage

movements are practically automatic, requires very little conscious attention

Traumatic Brain Injury (TBI)

in terms of memory loss, this diagnosis affects anterograde memory more frequently. Retrograde amnesia may be present for a short time period prior to the brain injury (and this time is variable), but it often "shrinks forward" (that is, more remote memories come back first, with memories of events just prior to injury coming back last or not at all)

stroke and anoxia

diagnoses where regions of the brains that are involved with memory are affected, where the hippocampus is especially vulnerable because it has a poor blood supply

Korsakoff's psychosis

seen often in people with alcoholism and people with B12 deficiencies, characterized by anterograde amnesia and lack of awareness of deficits, may lead to confabulation

Confabulation

filling in memory gaps in fabrication

Alzeimer's disease

early stages affect memory of recent events by preferentially affecting bilateral hippocampi, and later stages can affect all types of memory

psychogenic amnesia

dissociation, repression, functional neurological disorder (formerly called conversion disorder), and malingering, linked to memory loss of an emotional event or loss of autobiographical information

infantile amnesia

the inability to remember events from early childhood

benign senescent forgetfulness

cognitive decline associated with normal aging

1 mm/day

pns fibers regrow after injury, at the axonal regeneration rate of ____

crush injuries

regenerate well because the "pipes are laid" to guide axons where to grow

complete nerve transaction

often leads to the axon growing aberrantly, without the guidance of where to connect, therefore, complete recovery is rare

CNS neurons

do not typically regenerate because glial cells impede growth by laying down scar tissue and producing molecules that impede neuronal growth, axons do not reestablish connections and parent cell bodies atrophy, and if damage is done to the cell body or axons near the cell body, the whole neuron dies