Brain Milestones

• Gestational Month 8
  • Most neurons ever have
  • Ultrasound shows REM (help with wiring potentially)
  • Hearing is good, languafe learn begins
  • brain wabves can be recorded
• 3 years
  • brain 90-95% of adult size
  • Synamptic density is 50% higher than adulthood
  • Myelination at peak rate
  • Hippocampus almost mature
• 4-11 years: Special prefrontal newtowrks
• Puberty max level of grey matter volume and cortical thickening.
  • Largely driven by sex hormones
    teen to mid-20s
• grey matter begins to thin
• experience plays sig. role in process

Adolescene

• Cortical Growth and Thinning
• White matter grows in a linear fashion
• "Social brain" components are last to mature

The Adolescent Brian

• Fronta; :obes incompletly myelinated
• Connections between front and limbic system are immature
• decsions more emotional than rational
• bursto f sex hormone acitivty
• high levels of melatonin
• decreased levels of dopamine and serotonin
  • Low serotonin linked with aggression and violence

The Adult Brain

• Mature at 25
• Mylenation complete
• No changes until 45
• weight and gray matter vol. dec. gradually
• fluid intelligence dec. by age 25
• many women not fullly menopausal until 50s, begins in 30s
• Mid-life adults need healthy habits

Health Brain Aging

• Multiple reserve factors
  • Basic intelligence
  • spiriotuality
  • social relationships
  • multilingualism
• Changes in same pathways impacted by dementia
• Posterior-anterior shift
  • Shift of functions to anterior part of brain
• Weaker default mode network connections
  • involve in self-reference thought
  • reduce risk of depression in older adults

Adult neurogenesis

Most up to 18 months

• human begins diff. than other animals
• Skepticle of this occuring in humans
• Migration occurs throughout life
• hippocampus does not repair in humans
• The ventricular zone & The hippocampus might repair in animals