Wk.2 L3 - Brain Development - Wiring and Maintaining the Circiut Flashcards
LO
- Understand major processes which generate neural connectivity and their approximate timing
- Demonstrate an awareness of changes that occur in the nervous system across the lifespan and the factors that can influence them
Axonal Growth genes navigating to targets
Via Successive turning decisions:
Growth cones on the axon receptor guide the neuron cells around to navigate the environment.
- Finds best place to grow and build connections within the brain or body
- Acts like a guide through a maze towards the target region
Refinement of connections
Driven by experience after the child is born
- Growth cones correct neurons throughout time
- Neuron projections are refined, some removed and some reinforced.
Activity patterns are important for refining synaptic corrections
Peak periods of synaptic refinement differ between brain regions. Correlative with maturation
- Periods of synapses refining leads ti maturation of the circuit (few years after birth, refining is heavy, then steadies)
- Prefrontal cortex matures between 20-60
Changes in the mature brain
Volume declines 5% per decade after 40YO and accelerates after 70
- Grey and white matter decrease
Decreased levels of neurotransmitters
Loss of Myelin
Consequences of changes in the mature brain
- Decreased processing/ reaction speed
- Memory has executive decline
- Sensory perception declines
Causes of changes in the mature brain
- Changes to blood flow, hormones, mitochrondria & DNA
- Accumulation of toxic and misfolded proteins
- Genes Vs lifestyle
Influences on the rate of brain aging
- Genes
- Cognitive reserve
- Education
- Exercise
- Diet
- Sleep
- Alcohol/ drug/ toxin exposure
- Stress
- Injury
- Social interaction
- Other cognitive (music, puzzles, language, new places/ experiences)
