““FROM THE BRAIN AND THE BRAIN FROM THE BRAIN AND THE BRAIN ALONEALONE

ARISE OUR PLEASURES, JOYS, ARISE OUR PLEASURES, JOYS, LAUGHTERLAUGHTER

AND JESTS, AS WELL AS OUR AND JESTS, AS WELL AS OUR SORROWS, PAINS AND GRIEFS”SORROWS, PAINS AND GRIEFS”

HIPPOCRATES ca.460 B.C.- ca.370

B.C.

BRAIN COMMUNICATIONBRAIN COMMUNICATION

IN OUR BRAINS, WE HAVE

100 BILLION NEURONS

13.5 MILLION NEURONS IN THE SPINAL CORD ALONE

A SINGLE NEURON MAY HAVE UP 10,000 SYNAPSES SO THERE

COULD BE ABOUT1 QUADRILLION SYNAPSES IN THE

BRAIN

MESSAGES IN THENEURONS TRAVELTHROUGHELECTRICALAND CHEMICALIMPULSES

NEURONS CAN FIRE OVER AND OVERAGAIN ON AN AVERAGE OF 300-400TIMES A SECOND

CERTAIN IMPULSES MAY TRAVELUP TO 250 MILES PER HOUR

DENDRITES (SHORT FIBERS) RECEIVE THEMESSAGE FROM A CELL WHICH IS SENTTHROUGH THE CELL BODY AND THROUGHTHE AXON (LONG FIBERS)

THE AXONCARRIESTHE ELECTRICALIMPULSE TO THE AXONTERMINALWHERENEURO-TRANSMITTERSARE LOCATED.

SOME

NEURONS

MAY BE

3 FEET LONG !

NO NEURONS TOUCHEACH OTHER. THE SMALLSPACE SEPARATING THEM IS CALLED A SYNAPSE. THE ELECTRICAL MESSAGE CANNOT JUMPACROSS THE SYNAPSE SO THE MESSAGE IS SENTTHROUGH A CHEMICALMESSAGE CALLED ANEUROTRANSMITTER.

THE CHEMICAL MESSAGE IS THEN RECEIVED BY THE DENDRITE OF THE NEXT CELL WHICH TRIGGERS

AN ELECTRICAL IMPULSE THROUGH THE RECEIVING CELL

IN ADDITION, THERE ARE ABOUTONE TRILLION GLIAL CELLS IN

THE BRAIN

GLIAL CELLS DO NOT SEND ELECTROCHEMICAL SIGNALS LIKENEURONS.

THEY SUPPORT THE NEURONS IN THEFOLLOWING WAYS:

THEY ARE 10 TIMES MORE NUMEROUSTHAN NEURONS

GLIAL CELLS

PROVIDE STRUCTURAL SUPPORTPROVIDE NUTRITIONAL SUPPORTHELP WITH CELL MAINTENANCE

CONNECTS SENSORY NEURONS AND MOTOR NEURONS

S ensory neuronsA fferent neuronsM otor neuronsE fferent neurons

NEUROTRANSMITTERSNEUROTRANSMITTERS ACETYLCHOLINEACETYLCHOLINE (ACH)-basic bodily (ACH)-basic bodily

processes like movementprocesses like movement Botulism shuts off release of ACHBotulism shuts off release of ACH DOPAMINEDOPAMINE – control of body – control of body

movement, mood (Alzheimer’s and movement, mood (Alzheimer’s and Parkinson’s)Parkinson’s)

(some schizophrenics have excess)(some schizophrenics have excess) ENDORPHINSENDORPHINS – relieves pain increases – relieves pain increases

sense of well-being (morphine within)sense of well-being (morphine within) SEROTONINSEROTONIN-plays role in mood, body -plays role in mood, body

temperature, sleeptemperature, sleep

WE HAVE KNOWN ABOUT ELECTRICAL MESSAGESFOR MANY YEARS, p.58

BUT OUR KNOWLEDGE OF THE CHEMICAL FUNCTIONS IS RELATIVELY NEW.SCIENTISTS HAVE IDENTIFIED OVER 300NEUROTRANSMITTERS. SOME ARE:

GLUTAMATE DOPAMINE ACETYLCHOLINE ENDORPHINSNOREPHENEPRHINE GABA

(GLAN) SEROTONIN (DEGA Star)EXCITATORY INHIBITORY