2. Outline
Review the Action Potential
What happens when the action potential reaches the
axon terminal?
Synaptic Connections
Neurotransmission
Types of Receptors
Ionotropic vs. Metabotropic
Excitation vs. Inhibition
Temporal vs. Spatial Summation
Neurotransmitters
8. Two Types of Receptors
Ionotropic Metabotropic
Channel opens in
response to ion binding
Contains 4-5 subunits that
make up the receptor
structure
Fast speed of action
• Channel opens in
response to second
messengers
• Contains 1 subunit that
makes up the receptor
structure
• Slow speed of action
12. Receptors can have an excitatory or
inhibitory effect.
Excitatory Postsynaptic
Potential (EPSP)
Inhibitory Postsynaptic
Potential (IPSP)
Promotes excitation of
the postsynaptic
membrane
Graded potential that
decays over time and
space
Cumulative effect of EPSPs
are the basis for temporal
and spatial summation
Temporary
hyperpolarization of a
membrane- prevent action
potentials
How?
13. Summation
Temporal Summation Spatial Summation
Many stimuli in a close
span of time
Repeated stimuli can have
a cumulative effect and
can produce a nerve
impulse when a single
stimuli is too weak
Many neurons firing
simultaneously in the
same location
Synaptic input from
several locations can have
a cumulative effect and
trigger a nerve impulse
17. Long Term Potentiation (LTP)
Creating new or stronger synapses
Occurs by repeated stimulation, an increase in dendritic
receptors, an increase in neurotransmitters
New synapses can be formed in the olfactory system and
in the hippocampus
