Neurons Cellular and Network Properties Integration Divergence Figure 825a Integration Convergence Figure 825b Integration The Abundance of Synapses on a Postsynaptic Neuron Figure 826 Axon terminals ID: 318139
Download Presentation The PPT/PDF document "Chapter 8c" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Chapter 8c
Neurons: Cellular and Network PropertiesSlide2
Integration: Divergence
Figure 8-25aSlide3
Integration: Convergence
Figure 8-25bSlide4
Integration: The Abundance of Synapses on a Postsynaptic Neuron
Figure 8-26
Axon terminals
of presynaptic
neurons
Axon
Glial cell
processes
Dendrite of
postsynaptic
neuronSlide5
Integration: Purkinje cell
The highly branched dendrites of a Purkinje cell (neuron) demonstrate convergence
Figure 8-27Slide6
Integration: Spatial Summation
Figure 8-28a, step 1
1
Three excitatory neurons
fire. Their graded potentials
separately are all below
threshold.
T
rigger zone
Presynaptic
axon terminal
Action
potential
(a)
1Slide7
Integration: Spatial Summation
Figure 8-28a, step 2
1
Three excitatory neurons
fire. Their graded potentials
separately are all below
threshold.
Graded potentials arrive at
trigger zone together and sum
to create a suprathreshold
signal.
T
rigger zone
Presynaptic
axon terminal
Action
potential
(a)
1
2
2Slide8
Integration: Spatial Summation
Figure 8-28a, step 3
1
Three excitatory neurons
fire. Their graded potentials
separately are all below
threshold.
An action potential is
generated.
Graded potentials arrive at
trigger zone together and sum
to create a suprathreshold
signal.
T
rigger zone
Presynaptic
axon terminal
Action
potential
(a)
1
2
2
3
3Slide9
Integration: Spatial Summation
Figure 8-28a
1
Three excitatory neurons
fire. Their graded potentials
separately are all below
threshold.
An action potential is
generated.
Graded potentials arrive at
trigger zone together and sum
to create a suprathreshold
signal.
T
rigger zone
Presynaptic
axon terminal
Action
potential
(a)
1
2
2
3
3Slide10
Integration: Spatial Summation
Figure 8-28b, step 1
1
One inhibitory and two
excitatory neurons fire.
Inhibitory
neuron
Trigger zone
(b)
No
action potential
1Slide11
Integration: Spatial Summation
Figure 8-28b, step 2
1
The summed potentials
are below threshold, so
no action potential is
generated.
One inhibitory and two
excitatory neurons fire.
Inhibitory
neuron
Trigger zone
(b)
No
action potential
1
2
2Slide12
Integration: Spatial Summation
Figure 8-28b
1
The summed potentials
are below threshold, so
no action potential is
generated.
One inhibitory and two
excitatory neurons fire.
Inhibitory
neuron
Trigger zone
(b)
No
action potential
1
2
2Slide13
Integration: Temporal Summation
Figure 8-29aSlide14
Integration: Temporal Summation
Figure 8-29bSlide15
Integration: Presynaptic Inhibition
Figure 8-31a
3
2
1
3
2
1
An action potential
is generated.
An excitatory neuron
fires.
An inhibitory neuron fires, blocking
neurotransmitter release at one synapse.
(a) Presynaptic inhibition
Presynaptic
axon terminal
Action potential
Target cell
No neurotransmitter
release
No response
Neurotransmitter
released
Inhibitory neuron
Excitatory
neuron
Response
ResponseSlide16
Integration: Postsynaptic Inhibition
Figure 8-31b
1
2
3
4
Modulated signal in
postsynaptic neuron
below threshold.
One excitatory and one
inhibitory presynaptic
neuron fire.
No action potential
initiated at trigger zone.
No response in
any target cell.
Inhibitory neuron modulates the signal.
Excitatory
neuron
(b) Postsynaptic inhibition
No response
No response
No response
IPSP
+
EPSP
PLAY
Interactive Physiology
®
Animation:
Nervous II: Synaptic Potentials and Cellular IntegrationSlide17
Figure 8-33
Integration: Growth Cones of a Developing Axon
Survival of neurons depend on neurotrophic factors Slide18
Integration: Injury to Neurons
Figure 8-34
Axon
Myelin
Proximal stump
Distal stump
Site of injurySlide19
Summary
Organization of the nervous system
CNS – brain and spinal cord
PNS – peripheral nerves and ganglia, sensory receptors
Afferent – sensory
Efferent motor
Somatic
Autonomic
Autonomic
Sympathetic
ParasympatheticSlide20
Summary
Cells of the nervous system
Cell body, dendrites, axon, and axon terminal
Interneurons, synapse, postsynaptic cell, presynaptic cell, synaptic cleft, and axonal transport
Glial cells, Schwann cells, satellite cells, microglial, oligodendrocytes, astrocytes, and ependymal cells
Myelin sheaths, nodes of Ranvier, and neural stem cellsSlide21
Summary
Electrical signals in neurons
GHK equation, graded potentials, local current flow, action potentials, trigger zone, threshold, and all-or-none depolarizations
Activation gate, inactivation gate, absolute refractory period, relative refractory period, and conductionSlide22
Summary
Cell-to-cell communication
Electrical synapses, chemical synapses, and synaptic vesicles
Cholinergic neurons, adrenergic neurons, acetylcholine, norepinephrine, glutamate, GABA, serotonin, adenosine, and nitric oxide
Fast synaptic potentials and slow synaptic potentials
Integration of neural information transfer
Divergence, convergence, spatial summation, temporal summation, presynaptic modulation, postsynaptic modulation, and long-term potentiation