Neural communication

Soma (cell body)

Contains nucleus and cell machinery

Dendrites

Receives many incoming signals

Axon hillock/initial segment

Integrates inputs, action potential may begin if threshold is met

Axon

Conducts the electrical impulse away from the soma

Axon terminals

Communicate with target cells

Glial cells

Support neurones, provide metabolic/immune support and contribute to barriers

Myelin

Electrical insulation around many axons

Nodes of ranvier

Gaps between myelin segments where action potentials are regenerated

Which matters of the brain have which parts of a neuron?

Grey matter→ neuronal cell bodies/dendrites

White matter→ axons, often myelinated

Leak channel

Open much of the time, contributes to resting membrane potential

Voltage-gated channel

Opens in response to changes in membrane voltage

Ligand-gated channel

Opens when a chemical ligand, such as a neurotransmitter binds

State what occurs in synaptic transmission in 7 steps

1. An action potentials arrives at the pre synaptic axon terminal

2. Voltage-gated calcium channels open and Ca enters the terminal

3. Calcium triggers synaptic vesicles to fuse with the pre synaptic membrane

4. Neurotransmitter is released into the synaptic cleft

5. Neurotransmitter binds to receptors on the postsynaptic cell

6. Receptor activation changes ion-channel activity and produces a post synaptic potential

7. Neurotransmitter is cleared, for example by reuptake or enzymatic breakdown

EPSP and e.g.?

Excitatory postsynaptic potential, increases likelihood of threshold met e.g. glutamate

IPSP and e.g.?

Inhibitory postsynaptic potential, decreases likelihood of threshold met e.g. gaba

Spatial summation

Multiple impulses from presynaptic neurones arrive at one postsynaptic neurone to combine

Temporal summation

When one presynaptic neurone sends repeated impulses in quick succession to combine

What is the primary auditory complex associated with?

The Brodmann areas 41/42

What does auditory attention involve?

Neural processing that helps a listener focus on one speaker amid competing sound and efferent pathways ca modulate auditory processing

What is Brodmanns area 22 associated with?

Auditory association and language comprehension

What can demyelination do?

Disrupt neural signalling e.g. multiple sclerosis