NEURONS

  • Signals WITHIN neurons are transmitted ELECTRICALLY

  • Signals BETWEEN neurons are transmitted CHEMICALLY

Process of transmittion down a neuron:

  • Signal enters through dendrites

  • Travels down dendrites to cell body

  • Travels to axon to the axon terminal

  • Then transferred to the synapse

Neurons = NEGATIVELY charged in RESTING STATE

Signal recieved by dendrite makes cell TEMPORARILY POSITIVELY charged

  • Action potential = travels down axon terminal

MOTOR NEURON

  • Long axons

  • Short dendrites

  • Signals from CNS to organs and muscles

SENSORY NEURON

  • Short axons

  • Long dendrites

  • Signals to CNS from PNS

RELAY NEURON

  • Short axons

  • Short dendrites

  • Connects neurons

SYNAPTIC TRANSMITTION

Process by which singla is carried across a synapse between two neurons through the use of neurotransmitters (NTs)

  • Electrical signal down PRE-SYNAPTIC NEURON

  • Triggers movement of NEUROTRANSMITTERS in VESICLES - edge of PRE-SYNAPTIC NEURON

  • Neurotransmitters relased into SYNAPTIC GAP and diffuse across gap

  • Bind to RECEPTORS on the POST-SYNAPTIC NEURON and trigger electrical signal down post-synaptic neuron

  • Neurotransmitters left in SYNAPTIC GAP go back to PRE-SYNAPTIC NEURON

RESEARCH = YAMAMOTO AND KITAZAWA

EXITATORY - Increase posititve charge, and therefore increase the chance of the postsynaptic neuron firing

INHIBITORY - Increase negative charge, and therefore decrease the chance of the postsynaptic neuron firing

SUMMATION:

  • If EXCITATORY outweigh INHIBITORY the postsynaptic WILL FIRE

  • If INHIBITORY outweight EXCITATORY the postsynaptic will NOT FIRE