Download Introduction to Neuroscience

PS1000
Introduction to Neuroscience
Dr Claire Gibson
School of Psychology, University of Leicester
[email protected]
1. Functional Neuroanatomy – The Nervous
System and Behaviour
2. Development and Plasticity of the Nervous System
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Functional Neuroanatomy
The Nervous System and Behaviour
Overview
• Cells of the nervous system (NS)
• Gross neuroanatomy
Introduction to the larger-scale neural structures that are
constructed from the cellular building blocks
• Functional neuroanatomy
Correlating anatomy with behaviour
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Cells of the nervous system
• Nerve cells (neurons)
– specialised cells
– convey sensory information into the brain
– transmit commands from the brain to control organs
and muscles,
– thought, feeling, action
– form complex circuits
• Glial cells
– support (variety of mechanisms)
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The Neuron
• Camillo Golgi (1843-1926)
• Neurons were continuous with one
another
• Nearly endless network of connected
tubes
• Revolutionary staining
• Santiago Ramon y Cajal
(1852-1934)
• Used Golgi’s staining techniques
• Neurones are not continuous with
one anotehr
• Small gaps exist
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The Neuron Doctrine
• States that;
The brain is composed of separate neurons (and
other cells) that are independent structurally,
metabolically and functionally.
Information is transmitted from cell to cell across
tiny gaps (synapses – Charles Sherrington).
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Structure of the Neuron
• Common to all neurons;
1. Input zone
Cellular extensions (dendrites) which receive inputs
from other neurones, branched
2. Integration zone
Cell body region
3. Conduction zone
A single extension (axon) transmits information away
from the cell body
4. Output zone
Axon terminals (synaptic boutons), communicate the
cell’s activity to other cells
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Classification of neurones
1. Shape
2. Size
3. Function
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Classification of neurones
1. Shape
1. Bipolar neurones
2. Monopolar neurones
3. Multipolar neurones
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Classification of neurones
2. Size
•
considerable variety in shape and size
•
larger neurones
more complex inputs/outputs
cover greater distances
convey information more rapidly
….than smaller neurones
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Classification of neurones
3. Function
i) motor neuron (motoneuron)
located in spinal cord,
transmits information from the spinal cord to the
muscles,
ii) sensory neuron
a neuron directly affected by changes in the
environment (e.g. touch)
iii) Interneuron
neither a sensory or motoneuron,
receives information from and sends output to other
neurones,
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Glial cells
• Glia = glue (greek)
• Originally thought to simply ‘stick’ NS together
• Structural support
• Communicate (with each other and
neurones)
• Directly affect neuronal functioning
– Provide raw materials and chemical signals
– Directly affect neuronal structure and excitability,
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Glial cells
Dendrites
Astrocyte
Oligodendrocyte
Neuron cell body
Main types; astrocytes, oligodendrocytes, microglial cells
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Synapses (PS1003)
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The Nervous System
• Central Nervous System (CNS)
– Brain
– Spinal cord
• Peripheral Nervous System
(PNS)
– Cranial nerves
– Spinal nerves
– Autonomic nervous system
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The Brain
• 1400g (~2% body weight)
• Cerebral hemispheres
• Convolutions = folding= gyri (gyrus)
• Separated from each other by sulci
(sulcus)
• White matter – fiber tracts
• Grey matter – cell bodies and
dendrites (lack myelin)
• CNS = hierarchial
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Forebrain
•
Cerebral hemispheres,
thalamus, hypothalamus
•
Cerebral hemispheres
–
–
–
–
Frontal
Parietal
Occipital
Temporal
(bones)
•
Corpus callosum
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Structure
Major Function
Frontal Lobe
Motor cortex
Basal ganglia
Broca’s area
Prefrontal cortex
Plans and executes voluntary movements
Smoothes movements
Controls speech
Planning, impulse control
Parietal lobes
Somatosensory cortex
Association cortex
Projection area for body senses
Location of body and objects in space
Temporal lobes
Auditory cortex
Wernicke’s area
Inferior temporal cortex
Auditory information
Language area – meaning
Visual identification of objects
Occipital lobes
Primary visual cortex
Visual association cortex
Projection area for visual information
Processes components of visual information
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Support and nourishment for the brain
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Support and nourishment for the brain
• Ventricular system
• Cerebrospinal fluid (CSF)
• Choroid plexus
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Relating structure to function
The case of Phineas Gage (1848)
• 25-yr old construction worker
• 3.5 foot long tamping iron through cheek and
out of skull
• Regained consciousness, talk, walk,
• No impairment of; speech, learning, memory,
intelligence
• Dramatic personality changes
• Post-mortem – damage to both areas of
frontal lobe for processing emotions and
making rational decisions
• Localisation of function
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Summary
•
•
•
•
•
Neurons and glia
The neuron doctrine
Classification of neurons
Anatomy of the brain (forebrain)
Support and nourishment for the brain –
meninges, CSF
• Localisation of functions within the brain
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