Brain Bee Brain Facts

YOUR COMPLEX BRAIN

  • brain has ~ 86 billion neurons (nerve cells)

  • all neurons in brain are used

  • neurons exchange electrical signals w/ each other

    • creates circuits that forms nervous system

      • along w/ nerves

  • roundworms + fruit flies + zebrafish + salamanders + mice + monkeys all are similar to human nervous system

  • nervous system keeps bodies in sync by communicating w/ other parts of body

    • ex. cardiovascular system, gastrointestinal system, immune system, etc

  • ¼ ppl worldwide face neurological/psychiatric condition

    • causes financial + social burdens

HOW NEURONS COMMUNICATE

  • neurons use electrical + chemical signals to communicate

  • sensory neurons create action potentials (electrical signals)

    • travel down neurons

    • can’t cross gap between 2 neurons

  • action potential is turned into chemical message

    • crosses synapse (gap)

    • release of chem messengers can trigger 2nd action potential in neuron on other side of synapse

      • can also result in release of chem messenger that blunts transmission of signal

  • synapse grows stronger w/ repeated activity

    • msg more likely to get through

    • neurons learn to pass on imp msgs + ignore the rest

HOW YOUR BRAIN PROCESSES INFO

  • circuits: made of neurons that relay msgs around brain + body

    • sensory circuits carry signals from sense receptors to brain

    • motor circuits send commands to muscles

    • simple circuits carry out automatic reflexes

    • complex circuits perform higher lvl activities

      • memory, decision making, perceiving world around

    • all circuits arise before birth

      • genes direct neurons to assemble into simple circuits

      • when neurons + connections change from new experiences + enviros, simple circuits → more complex

        • happens mostly during childhood

HOW EXPERIENCE SHAPES BRAIN

  • most neurons have been there since birth

    • most will stay until end of life

  • plasticity: brain is constantly changing

    • strengthens/weakens connections between neurons

  • brain damaged by injury/disease might be able to regain lost abilities

  • healthy brain neurons die too

    • during development, human brain grows excess neurons

    • synaptic pruning: happens early in life; brain eliminates extra cells

      • keeps connections you need

      • unused neurons can also wither away

REASONING, PLANNING, SOLVING PROBLEMS

  • brain combines all available info

    • can paint pic of world around

    • by using inference + instinct, brain can make sense of pic

  • brain makes + uses emotions

    • emotions = value judgements that help brain respond effectively to events

  • pictures assembled + feelings are used to form memories

    • stored by brain + used in future

  • consciousness requires that all these activities function normally

THE POWER OF LANGUAGE

  • humans communicate in ways that are more complicated than other animals

  • humans have larger cerebral cortex than animals

    • cerebral cortex has neural circuits dedicated to lanf

  • neurons in temporal + parietal + frontal lobes form circuits that interpret sounds + symbols of language

    • circuits are used to generate words+turn them into sounds + understand sounds that are heard

THE SOURCE OF CURIOSITY

  • brain runs on 25 watts of electricity

  • ~10000 types of neurons in brain

HOW RESEARCH BENEFITS HUMAN HEALTH

  • UN estimates that ¼ ppl worldwide are afflicted w/ neurological/psychiatric conditions

    • cause more total disabilities than heart attacks/cancers/ HIV (AIDS) every yr

    • $1.5 trillion leached from US economy

  • L-dopa helps millions of ppl beat back pain symptoms of Parkinson’s disease

  • Selective Serotonin Reuptake Inhibitors (ex. Prozac) to treat depression