Download 233 Brain & Behaviour: 1. Introduction

Basic neuroscience
Anatomy
J. Lauwereyns, Ph.D.
Professor
Graduate School of Systems Life Sciences
Kyushu University
[email protected]
The neuron
Chemical release
Detection
DNA
Transport
Insulation
Glia
In mammals: Axons are myelinated
Neuron communication
Neurons:
1. detect external environment
2. convert this sensory information
into cellular ‘language’
Simple reflex
Simple reflex
Touching a hot iron;
muscles of the arm contract,
withdraw the arm
Simple reflex
Dendrites of
a sensory neuron
signal the painful
stimulus
Simple reflex
This triggers
an action potential
in the axon
Simple reflex
This activates
an interneuron
in the
spinal
cord
Simple reflex
This activates
an interneuron
in the
spinal
cord,
which, in turn,
activates a motor neuron
Simple reflex
Now the motor
neuron sends a
series of action potentials
to the muscle, which contracts
Simple reflex
Note: for simplicity, only 3 neurons and 1 muscle are
shown. In reality, even this simple reflex involves many
hundreds of neurons, and groups of muscles…
How does this work??
• Action potentials (or nerve impulses) form the
language of the brain, like computer bits or Morse
code
• Cells that can generate and conduct action potentials
have an excitable membrane
• When such cells are not generating impulses, the
membrane is at its resting potential
Flash forward!
Action potentials:
Visual
stimulus
Neuron’s
response
(action
potentials)
Neuron’s response
The brain’s information code
Visual stimulus
Data from a neuron in visual cortex
Back to the present…
The neuron
Chemical release
Detection
DNA
Transport
Insulation
Glia
In mammals: Axons are myelinated
‘Central dogma’ of molecular biology
DNA
Transcription
mRNA
Translation
Protein
The axon and its terminal
Close up of terminal button
Following an
action potential:
Neurotransmitters
will be released in
the synaptic cleft
and influence the
post-synaptic
neuron…
To be continued
Neuron communication
Two components:
• Within the neuron (action potentials)
• Between neurons (neurochemical release)
The logic of + and – in the brain
Inhibitory
“-”
Excitatory
“+”
Simple reflex
Touching a hot iron;
muscles of the arm contract,
withdraw the arm
The advantage of inhibitory control…
Returning to the example of the simple reflex,
and a desire not to let go of the hot casserole
1 human
2 monkey
3 cat
4 pigeon
5 possum
6 dog
neuraxis
dorsal
posterior
caudal
rostral
anterior
ventral
lateral
medial
rostral
neuraxis
ventral
dorsal
caudal
lateral
medial
dorsal
coronal
ventral
sagittal
rostral
caudal
transversal
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Meninges
Spinal cord
Ribs
Spinal nerves
Cranial nerves
Lung
Kidney
(Cauda equina)
Dorsal
Dura mater
Arachnoid membrane
Pia mater
Spinal nerve
SubVertebra
Fat
arachtissue
noid
space
Ventral
Dorsal
Dorsal
root
ganglion
To
Dorsal
brain
root
Dura mater
Afferent
Arachnoid membrane
axon
Pia mater
Ventral root
Efferent
axon
Spinal nerve
Motor
neuron
SubVertebra
Fat
arachtissue
noid
space
Ventral
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Meninges
Spinal cord
Ribs
Spinal nerves
Cranial nerves
Lung
Kidney
(Cauda equina)
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Let’s take
a look
Dura mater
Subdural
space
Arachnoid
membrane
Subarachnoid
space
(Arachnoid trabeculae)
Pia mater
The meninges
Surface of the
brain
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Ventricular system:
flotation, shock absorption
Lateral ventricle
Third ventricle
Massa
intermedia
Cerebral
aqueduct
Fourth
ventricle
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Nervous system
1 Central Nervous System
2 Peripheral Nervous System
3 The cranial nerves
4 The meninges
5 The ventricular system
Cerebral cortex
(Telencephalon)
Limbic structures
Basal ganglia
Forebrain
Thalamus
(Diencephalon)
Midbrain
(Mesencephalon)
Hypothalamus
Tectum
(Substantia nigra,
Superior colliculus,…)
Cerebellum
(Metencephalon)
Hindbrain
(Myelencephalon)
Pons
Medulla
Cerebral cortex
(Telencephalon)
Limbic structures
Basal ganglia
Forebrain
Thalamus
(Diencephalon)
Midbrain
(Mesencephalon)
Hypothalamus
Tectum
(Substantia nigra,
Superior colliculus,…)
Cerebellum
(Metencephalon)
Hindbrain
(Myelencephalon)
Pons
Medulla
Cerebral cortex
Primary
Motor
cortex
Primary
Somatosensory
cortex
Primary
Visual cortex
Primary
Auditory
cortex
Cerebral cortex
Primary
Somatosensory
cortex
Parietal lobe
Primary
Motor
cortex
Frontal lobe
Primary
Visual cortex
Primary
Auditory
cortex
Temporal
Medulla
lobe
Spinal cord
Occipital
lobe
Cerebellum
Primary
Motor
cortex
Primary
Somatosensory
cortex
Right hemisphere
Primary
Visual cortex
Primary
Auditory cortex
Left hemisphere
Primary
Motor
cortex
Primary
Somatosensory
cortex
Right hemisphere
Central sulcus
Calcarine
fissure
Primary
Visual cortex
Lateral fissure
Primary
Auditory cortex
Left hemisphere
Fissure, sulcus: groove (major, minor)
Gyrus: a convolution of the cortex (separated by sulci or fissures)
Cerebral cortex
(Telencephalon)
Limbic structures
Basal ganglia
Forebrain
Thalamus
(Diencephalon)
Midbrain
(Mesencephalon)
Hypothalamus
Tectum
(Substantia nigra,
Superior colliculus,…)
Cerebellum
(Metencephalon)
Hindbrain
(Myelencephalon)
Pons
Medulla
Limbic structures
Limbic cortex
Corpus
callosum
(largest
Hippocampus
commissure,
connecting the two
hemispheres)
Pituitary gland
Cerebellum
Amygdala
Pons
Medulla
Spinal cord
Cerebral cortex
(Telencephalon)
Limbic structures
Basal ganglia
Forebrain
Thalamus
(Diencephalon)
Midbrain
(Mesencephalon)
Hypothalamus
Tectum
(Substantia nigra,
Superior colliculus,…)
Cerebellum
(Metencephalon)
Hindbrain
(Myelencephalon)
Pons
Medulla
Basal ganglia
+ (Diencephalon)
Caudate nucleus
and putamen
Thalamus
Hypothalamus
Globus
pallidus
Tail of caudate nucleus
(can’t see:
Substantia nigra)
Cerebral cortex
(Telencephalon)
Limbic structures
Basal ganglia
Forebrain
Thalamus
(Diencephalon)
Midbrain
(Mesencephalon)
Hypothalamus
Tectum
(Substantia nigra,
Superior colliculus,…)
Cerebellum
(Metencephalon)
Hindbrain
(Myelencephalon)
Pons
Medulla