06-09-2017 Wednesday
Neuroscience
- Human brain
➢ 1100-1400 g is the average weight
range of the brain.
➢ Blue whale has a largest brain.
➢ Birds brain are the smallest . 0.1g.
➢ Humans have bigger brains when
compared to the body size.
➢ 1/3rd of all calories are going to the
brain.
- Sleep stages :
➢ There is one sleep stage where the
brain is most active compared to
when we are awake.
- Development of the brain :
➢ Males have bigger brains when
compared to females in all ages.
➢ Females have larger brains when compared to their body size.
➢ The weight of the brain triples in 1 year. From 300g to 900g. After , there is a diffused cortical atrophy
after the person passes 70s. This is due to the accumulation of wear and tear pigment called
lipofuscin. The ageing process of shrinking of the brain is accelerated in Alzheimer’s and dementia.
- Facts about the brain :
➢ Cerebellum also called the little brain can detect sensory consequences of a motor movement. It
predicts the sensory consequence of a motor movement.
▪ Eg: When another person is tickling you, you cannot predict it and thus you are tickled.
▪Stress alters the neurons and their function.
▪There is a structure called locus coeruleus: It is a nuclei that releases Norepinephrine and
epinephrine. When the body is in stressful conditions/ panic. This is present in the pons.
• Etymology :
1. Locus : Spot
2. Coeruleus : DARK Blue
▪ This blue/azure color is because of the light scattering from the
neuromelanin in the noradrenergic nerve cell bodies.
▪ Two types :
• Good stress: For effective functioning you need stress. No stress= no effort
• Bad stress
➢ Dreaming :
▪ Dreaming requires more brain than being awake.
▪ Two major stages of sleep:
• REM sleep
1. Dreaming occurs here.
2. The cerebral blood flow to the brain is higher in the sleep. The flow increases
except in the frontal lobe. Frontal lobe creates social inhibition distinguishing us
from animals. It allows for socially acceptable behavior. In dream, you don’t
have a socially acceptable behavior which is why you may kill and do anything
that you may want to.
, • Non REM sleep
➢ Music :
▪ Music helps in brain organisation.
• Opera singers awake sleep neurons. There are neurons that are not active and are called
sleep neurons. Music can stimulate these neurons and wake them up.
➢ Average of 70000 thoughts a day.
▪ The communication between the synapses is very intense.
➢ Amygdyla : This is in the medial part of the temporal lobe.
▪ It is the centre for fear and emotions.
• Eg: When is need to be aggressive?
▪ It is also needed to understand the emotions. Therefore it can read facial cues.
➢ EEG/ electro encephalogram
▪ Electrodes are placed on where there is high neuronal activity.
▪ This can be used to monitor both sleep and seizures.
➢ Brain needs 20% of O2.
➢ You use your entire brain despite of the popular belief that you only use 10%.
▪ There are 20 supporting cells that surround each neuron. The glial cells play a very key role in
memory processing and how much of the brain you are using.
▪ Functions of glial cells :
• Support
• Faster conduction of impulses.
➢ Oxytocin:
▪ Functions :
• Milk ejection by contracting
the myoepithelial cells in the
nipples.
• Cuddling hormone
1. Love has several
phases.
▪ Lust:
Increased
testosterone
and
progesterone
▪ Attraction :
Dopamine or serotonin
• This is the stage of euphoria.
▪ Attachment phase
• Oxytocin plays a role here. Oxytocin is released in a long term
relationship.
• The same hormone is responsible for the milk ejection from the
mom when the baby cries in the other room. This is because the
mother and the son are extremely attached.
➢ Brain cannot feel pain
▪ This is because the brain parenchyma does not have pain receptors.
▪ Out of the three brain layers Duramater arachnoid mater and Piamater, only the duramater has
pain receptors.
• Stretching of duramater can cause head ache or stretching of blood vessels.
➢ There are 100,000 miles of blood vessels in the brain.
, - American crowbar case :
➢ This proved that each part of the brain is responsible for different
function.
➢ Phineas Gage was implanting dynamites and the crowbar went all the
way to his left check and to the frontal bone during an explosion. He
was unconscious for 30s and he survived the accident.
➢ Before the incident , the guy was humane but after the event his
behavior changed.
➢ What caused this :
▪ Anterior part of the frontal lobe is called the prefrontal
cortex which is important for behavior and personality and
establishes a socially acceptable behavior.
- Albert Einstein’s brain :
➢ He used most of his glial cells. Einstein’s brain had more glial cells and
there was difference in the architecture.
➢ IT also had a well developed prefrontal cortex.
➢ Glia means glue like.
- Medical Neuroscience :
➢ Neuroanatomy
➢ Neurophysiology
➢ Neuropathology: Infections,
➢ Neuropharmacology
▪ Treatments for Parkinson’s, Alzheimer’s, prion disease.
➢ Neuroradiology : CT and MRI
▪ MRI has T1 and T2
➢ Neurocytology and neuro embryology.
▪ Notochord induces neuro-ectoderm to form from ectoderm.
Neurocytology
- Rabies :
➢ Virion particles are released in the periphery but will inter the CNS.
➢ Vampire bat: Rabies
- There are two types of transport in a neuron.
➢ Anterograde
➢ Retrograde:
- Varicella virus :
➢ It affects the dermatome. Each Spinal nerve supplies strip of skin called a dermatome. Th following are
the spinal nerves.
▪ 8 cervical
▪ 12 Thoracic
▪ 5 Lumbar
▪ 5 Sacral
▪ 1: Coccygeal Making a total of 31 pairs of spinal nerves.
➢ It starts as painful blisters
- Tremors :
➢ Resting tremor: in parkinsonism. This is the type of tremor that occurs when the muscles are resting. It
reduces when the person starts to move his limb.
➢ Intention tremor : Tremor worsens when you want it to move towards where you want.
, ➢ Task specific tremor : This only occurs when you are doing a particular tast like playing a violin.
➢ Postural tremor : This is a tremor that occurs when you do a yoga position / keep a posture.
- Polio is caused by virus
➢ Causes paralysis of muscles.
Nervous system
- It is divided anatomically into
➢ CNS
▪ Cerebrum , Cerebellum and the spinal cord.
▪ Brain stem connects the cerebral hemispheres to the spinal cord.
▪ Parts of the brain stem:
• Mid brain
• Pons and
• Medulla.
➢ PNS
▪ Peripheral nerves coming out of CNS.
• Spinal nerves.
• Cranial nerves come from the brain stem. There are 12 pairs.
1. Olfactory : Present on the roof of nasal cavity piercing the cribriform plate.
2. Optic nerve
▪ These two does not arise from the brain stem but from the frontal
lobe/telencephalon.
3. 3,4 : From mid brain
4. 5,6,7,8 : Pons
5. 9-12: Medulla
- Divisions :
➢ Part between the cerebral hemispheres and the brain stem. This is called diencephalon.
➢ The cerebral hemispheres are called the telencephalon.
▪ The rostral end of the neural tube becomes the cerebral hemisphere and thus called
telencephalon.
➢ Cerebellum : Sits in the posterior cranial fossa.
➢ Medulla passes through the foramen magnum to become the spinal cord.
➢ The cut section of the spinal cord will have:
▪ Axons of the neurons is the white matter.
▪ The cell bodies of the neurons is the grey matter.
Neuroscience
- Human brain
➢ 1100-1400 g is the average weight
range of the brain.
➢ Blue whale has a largest brain.
➢ Birds brain are the smallest . 0.1g.
➢ Humans have bigger brains when
compared to the body size.
➢ 1/3rd of all calories are going to the
brain.
- Sleep stages :
➢ There is one sleep stage where the
brain is most active compared to
when we are awake.
- Development of the brain :
➢ Males have bigger brains when
compared to females in all ages.
➢ Females have larger brains when compared to their body size.
➢ The weight of the brain triples in 1 year. From 300g to 900g. After , there is a diffused cortical atrophy
after the person passes 70s. This is due to the accumulation of wear and tear pigment called
lipofuscin. The ageing process of shrinking of the brain is accelerated in Alzheimer’s and dementia.
- Facts about the brain :
➢ Cerebellum also called the little brain can detect sensory consequences of a motor movement. It
predicts the sensory consequence of a motor movement.
▪ Eg: When another person is tickling you, you cannot predict it and thus you are tickled.
▪Stress alters the neurons and their function.
▪There is a structure called locus coeruleus: It is a nuclei that releases Norepinephrine and
epinephrine. When the body is in stressful conditions/ panic. This is present in the pons.
• Etymology :
1. Locus : Spot
2. Coeruleus : DARK Blue
▪ This blue/azure color is because of the light scattering from the
neuromelanin in the noradrenergic nerve cell bodies.
▪ Two types :
• Good stress: For effective functioning you need stress. No stress= no effort
• Bad stress
➢ Dreaming :
▪ Dreaming requires more brain than being awake.
▪ Two major stages of sleep:
• REM sleep
1. Dreaming occurs here.
2. The cerebral blood flow to the brain is higher in the sleep. The flow increases
except in the frontal lobe. Frontal lobe creates social inhibition distinguishing us
from animals. It allows for socially acceptable behavior. In dream, you don’t
have a socially acceptable behavior which is why you may kill and do anything
that you may want to.
, • Non REM sleep
➢ Music :
▪ Music helps in brain organisation.
• Opera singers awake sleep neurons. There are neurons that are not active and are called
sleep neurons. Music can stimulate these neurons and wake them up.
➢ Average of 70000 thoughts a day.
▪ The communication between the synapses is very intense.
➢ Amygdyla : This is in the medial part of the temporal lobe.
▪ It is the centre for fear and emotions.
• Eg: When is need to be aggressive?
▪ It is also needed to understand the emotions. Therefore it can read facial cues.
➢ EEG/ electro encephalogram
▪ Electrodes are placed on where there is high neuronal activity.
▪ This can be used to monitor both sleep and seizures.
➢ Brain needs 20% of O2.
➢ You use your entire brain despite of the popular belief that you only use 10%.
▪ There are 20 supporting cells that surround each neuron. The glial cells play a very key role in
memory processing and how much of the brain you are using.
▪ Functions of glial cells :
• Support
• Faster conduction of impulses.
➢ Oxytocin:
▪ Functions :
• Milk ejection by contracting
the myoepithelial cells in the
nipples.
• Cuddling hormone
1. Love has several
phases.
▪ Lust:
Increased
testosterone
and
progesterone
▪ Attraction :
Dopamine or serotonin
• This is the stage of euphoria.
▪ Attachment phase
• Oxytocin plays a role here. Oxytocin is released in a long term
relationship.
• The same hormone is responsible for the milk ejection from the
mom when the baby cries in the other room. This is because the
mother and the son are extremely attached.
➢ Brain cannot feel pain
▪ This is because the brain parenchyma does not have pain receptors.
▪ Out of the three brain layers Duramater arachnoid mater and Piamater, only the duramater has
pain receptors.
• Stretching of duramater can cause head ache or stretching of blood vessels.
➢ There are 100,000 miles of blood vessels in the brain.
, - American crowbar case :
➢ This proved that each part of the brain is responsible for different
function.
➢ Phineas Gage was implanting dynamites and the crowbar went all the
way to his left check and to the frontal bone during an explosion. He
was unconscious for 30s and he survived the accident.
➢ Before the incident , the guy was humane but after the event his
behavior changed.
➢ What caused this :
▪ Anterior part of the frontal lobe is called the prefrontal
cortex which is important for behavior and personality and
establishes a socially acceptable behavior.
- Albert Einstein’s brain :
➢ He used most of his glial cells. Einstein’s brain had more glial cells and
there was difference in the architecture.
➢ IT also had a well developed prefrontal cortex.
➢ Glia means glue like.
- Medical Neuroscience :
➢ Neuroanatomy
➢ Neurophysiology
➢ Neuropathology: Infections,
➢ Neuropharmacology
▪ Treatments for Parkinson’s, Alzheimer’s, prion disease.
➢ Neuroradiology : CT and MRI
▪ MRI has T1 and T2
➢ Neurocytology and neuro embryology.
▪ Notochord induces neuro-ectoderm to form from ectoderm.
Neurocytology
- Rabies :
➢ Virion particles are released in the periphery but will inter the CNS.
➢ Vampire bat: Rabies
- There are two types of transport in a neuron.
➢ Anterograde
➢ Retrograde:
- Varicella virus :
➢ It affects the dermatome. Each Spinal nerve supplies strip of skin called a dermatome. Th following are
the spinal nerves.
▪ 8 cervical
▪ 12 Thoracic
▪ 5 Lumbar
▪ 5 Sacral
▪ 1: Coccygeal Making a total of 31 pairs of spinal nerves.
➢ It starts as painful blisters
- Tremors :
➢ Resting tremor: in parkinsonism. This is the type of tremor that occurs when the muscles are resting. It
reduces when the person starts to move his limb.
➢ Intention tremor : Tremor worsens when you want it to move towards where you want.
, ➢ Task specific tremor : This only occurs when you are doing a particular tast like playing a violin.
➢ Postural tremor : This is a tremor that occurs when you do a yoga position / keep a posture.
- Polio is caused by virus
➢ Causes paralysis of muscles.
Nervous system
- It is divided anatomically into
➢ CNS
▪ Cerebrum , Cerebellum and the spinal cord.
▪ Brain stem connects the cerebral hemispheres to the spinal cord.
▪ Parts of the brain stem:
• Mid brain
• Pons and
• Medulla.
➢ PNS
▪ Peripheral nerves coming out of CNS.
• Spinal nerves.
• Cranial nerves come from the brain stem. There are 12 pairs.
1. Olfactory : Present on the roof of nasal cavity piercing the cribriform plate.
2. Optic nerve
▪ These two does not arise from the brain stem but from the frontal
lobe/telencephalon.
3. 3,4 : From mid brain
4. 5,6,7,8 : Pons
5. 9-12: Medulla
- Divisions :
➢ Part between the cerebral hemispheres and the brain stem. This is called diencephalon.
➢ The cerebral hemispheres are called the telencephalon.
▪ The rostral end of the neural tube becomes the cerebral hemisphere and thus called
telencephalon.
➢ Cerebellum : Sits in the posterior cranial fossa.
➢ Medulla passes through the foramen magnum to become the spinal cord.
➢ The cut section of the spinal cord will have:
▪ Axons of the neurons is the white matter.
▪ The cell bodies of the neurons is the grey matter.
