Caffeine mimics adenosine, which usually makes you drowsy
How do neurons produce an electrical signal?
• Extracellular fluids outside neuron
• Inside neuron there are ions like Cl, A, Na, K
• Builds up a charge on the semipermeable cell membrane
How does a neuron code intensity?
How does one neuron communicate with another?
The Action Potential
• Resting Potential = 70 mV
• Depolarization = Na+ inflow
• Threshold = > 55 mV
• In 2 msec charge is +40 mV ie. Change in electrical energy
• Repolarization = K+ outflow
• Hyperpolarization = below resting potentials
• Absolute Refractory Period = neuron cannot be stimulated to generate action
• Relative Refractory Period = requires a stimulus to get neuron to threshold to
generate action potentialion Neural Communication
Remember Axons generate Action Potential
Rest of neuron generates Graded Potential
How to code intensity?
Neuron fires on allornothing fashion
Height of “spike” is fixed
Strong stimulus ▯More neurons
Intensity directly proportional to frequency of firing
Max frequency of firi