I. Neural Communication
a. Neuron: nerve cells (100 billion connects with +10-100 thousand)
b. Glial cells: support, myelin, waste-clearing
i. More glial than neuron and ratio of glial to neuron dictates biological
complexity
ii. Resting potential: -70 MV inside axon
c. Myelin Sheath: fatty tissue encasing axon
d. Node of Ranvier: space between myelin sheath -> creates high sodium levels
i. Ion pumps located in nodes
e. Action potentials: limited in how fast things can go
i. Refractory period: 1-2 milliseconds
ii. All or None transmission
iii. Action potential comes down, signals to vesicles to make way to edge of
neuron
1. They then fuse w/ plasma membrane
2. Neurotransmitter: released to synaptic cleft
3. Hook up to receivers
4. Neurotransmitters determine speed of response b/c depends on # of
synaptic gaps
f. Neurotransmitters
i. NT binds to receptor
ii. Ion channels open
iii. EPSP (excitatory postsynaptic potential)
1. Dopamine [+ions into cell]
iv. IPSP (inhibitory postsynaptic potential)
1. Gabba [- ions into cell, +ions out of cell]
a. Potential: message
b. Opens another ion channel
c. If it meets a threshold?
i. Fire another AP!
v. Adding of EPSPs and IPSPs: summation
1. Temporal summation: must be close in time
2. Spatial summation: must be close in area
a. Resting: -70
II. Sensation and Perception
a. Sensation: intake of raw info into brain (low level)
b. Perception: organization and interpretation of sensory input (high level)
i. Stimulus energy -> sensory receptors -> neural impulses -> brain
ii. Sensation --------------------------------- perception-------------|
