Neuroscience at Cell Level (2.2)

Week 2.2 Lecture Slides

Course Concept #2: The nervous system receives, interprets, and responds to information

This means that the nervous system gathers information from the body and environment, processes it, and coordinates it to where it needs to go

Why does Cellular Neuroscience matter in OT?

Movement, sensation, regulation, learning, fatigue, and participation depend on communication among nervous system cells

What are the 3 types of nerve cells:

Neurons, Glial Cells, Stem Cells

Neurons function:

Nerve cells receive, process and send signals throughout the body (communication)

• Chemical and electrical interactions

Neurons help to control:

• Movement

• Sensation

• Cognitive and behavioral processes

• Body response (autonomic)

Name the parts of a neuron:

Dendrite > Cell Body/Soma > Axon > Presynaptic Terminal

Dendrites function:

Short branch-like extensions that receive information

Soma/Cell Body function:

Maintains the cell and integrates information

Axon function:

Sends information away from the Soma

Presynaptic terminal function:

Communicates with the next cell

What is the information flow through a neuron?

Dendrite > Soma/Cell body > Axon > Presynaptic Terminal

What structure is most associated with white matter?

Myelinated axons

What is the name of the electrical difference across a neuron’s membrane?

Resting membrane potential

What changes the electrical state of a neuron?

Ion movement

What causes an action potential to begin?

The ion movement must be high enough to change that electrical state, this will initiate the action potential to start

What is an action potential?

an electrical signal that travels down the axon

Action potential movement:

Travels down the axon like a wave, as one becomes active it then triggers the next section

• This continues until the signal reaches the presynaptic terminal

The neurotransmitter crosses the _______ ___ to reach the next cell

synaptic gap/cleft

What 2 ways do neurons communicate?

• Within a neuron (Electrical)

• Between Neurons (Chemical)

At most synapses in the mature CNS, communication between neurons happens through ______ messengers called neurotransmitters

chemical

Big picture Neural communication is …

electrochemical

What factors help to create faster propogation?

• Larger diameter axon

• Myelination

Nodes of Ranvier definition:

gaps between the myelin sheath on the axon

Saltatory Conduction

Action potential “leaps” from node to node

What are the 4 types of Neuroglia in the CNS:

• Ependymal cells

• Oligodendrocytes

• Astrocytes

• Microglia

What are the 2 types of Neuroglia in the PNS:

• Satellite cells

• Schwann cells

Oligodendrocytes function:

Form Myelin in the CNS

• CNS

Schwann cells function:

form Myelin in the PNS; support peripheral nerve repair

• PNS

Astrocytes function:

Support neural environment, nutrients, synapses, create blood-brain barrier

• CNS

Microglia

imune defense and clean up

• CNS

When myelin is damaged, signals may become…

• Slower

• Less efficient

• Disrupted

• Fatiguing to sustain

Functional effects of damaged myelin:

• Weakness

• Sensory changes

• Coordination problems

• Fatigue

• Changes in IADL/ADL performance

MS is affected by…

demyelination in the CNS

Guillan-Barre Syndrome is affected by…

demyelination in PNS

Glial cells function

To support, nourish, and protect neurons