how to study the brain Flashcards

(32 cards)

1
Q

What is a stroke?

A

-Causes motor language impairments
-Depends on which brain region is damaged

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2
Q

What is Alzheimer’s disease?

A

-Damage starts in medial temporal (hippocampus)

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3
Q

What is Parkinsons disease?

A

-Degeneration of neuron’s in substantial nigra (midbrain)

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4
Q

Describe the case of Patient Leborgne

A

-Suffered stroke
-Damage to left side of frontal cortex (Broca’s area)
-Lack of speech, could only say ‘tan’

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5
Q

Describe the case of Phineas Gage

A

-Metal rod through frontal cortex
-Behaviour changed and became impulsive

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6
Q

Is hippocampus both necessary and efficient?

A

-Hippocampus is necessary for spatial and declarative memory but it isn’t sufficient

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7
Q

(R) What is a lesion?

A

-Wound or injury

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8
Q

What are the 6 methods used to study the brain?

A

-Behavioural studies
-Manipulations of brain functions
-Neuroanatomy and histology
-Electrophysiology
-Imaging (MRI and PET)
-Computational models/brain based devices

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9
Q

Describe the use of manipulations of brain functions

A

-Neurological patients/ones with brain damage, if you know which part is damaged then you can figure out the role
-Conducted more on animals to be more ethical

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10
Q

Describe the use of neuroanatomy and histology

A

-Connection to other brain sites

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11
Q

Describe the use of electrophysiology

A

-Listen to electrical activity of neurons

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12
Q

Describe the use of imaging (MRI and PET)

A

-Non-invasive methods

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13
Q

Describe the use of computational models/brain based devices

A

-Once we know how a brain region links to a psychological process, we can build a model on how a brain circuit links to functions

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14
Q

Describe in detail what happened in the case of Patient H.M.

A

-Had his hippocampus removed to stop epileptic seizures
-Used behavioural and cognitive analysis
-Found that he had impairments in spatial and declarative memory

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15
Q

What is spatial memory?

A

-Memory of directions and locations
-He couldn’t form new ones

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16
Q

What is declarative memory?

A

-Memory that we can recollect
-Includes semantic and episodic memory

17
Q

(R) Describe stereotaxic surgery

A

-Ability to locate objects within a space
-Keeps animals head in position and an arm that moves an electrode through measured distances in all 3 axes of space

18
Q

What are optogentics?

A

-Manipulating specific neurons in the brain so that they become light sensitive
-Shining a light means you can either activate or inhibit neurons

19
Q

What is Trans-cranial magnetic stimulation (TMS)?

A

-Disrupt electrical activity but inducing magnetic field on the surface of the brain

20
Q

What occurs during neuronal tract tracing?

A

-Tracer is injected into 1 brain region
-Travels in direction of action potential

21
Q

What happens in diffusion magnetic resonance imaging?

A

-Highlight white fibre tracts

22
Q

How do you record the electrical activity of the brain?

A

-Planting electrodes into the brain region to record specific electrical signals from neurons
-Each neuron has different firing rates
-Local field potential (LFP) recordings, where you record electrical potentials generated by neurons known as field potentials

23
Q

How is water maze used to look at learning deficits after hippocampal lesions in rats?

A

-Rats don’t have declarative memory but do have spatial memory
-Spatial cues placed to find the correct location
-Get faster each time
-Remove it and track their pathway

24
Q

What are invasive single-unit and LFP recordings?

A

-Only conducted in rare cases for pre-surgical evaluation of epilepsy patients
-Neurologist would plant electrodes to figure out where the seizure is coming from, so that the surgery is conducted on the smallest area needed

25
What is a surface EEG?
-Spontaneous and event-related (evoked) -Record electrical activity generated by the brain by putting electrodes on the surface of the brain -Can be used to diagnose epilepsy
26
What is magnetoencephalography?
-Conducted with neuromagnetometers -Measures the small magnetic-field changes that arise from the electrical voltage changes due to brain activity -Better spatial resolution than EEG (<1cm) -Require a large machine that is very expensive and difficult to do on children
27
What is magnetic resonance imaging (MRI)?
-Images are generated from MR signal -Nuclei of spinning hydrogen atoms align with magnetic field -These are aligned by a strong magnetic field -Excited by magnetic pulse -Doesn't use x-rays
28
Describe the use of structural MRI of the brain
-Non-invasive imaging of brain structure -Based on MRI contrast between different tissue types due to different densities of H nuclei -Would have been used on H.M to confirm which area is damaged
29
Describe the use of functional MRI of the brain
-Non-invasive imaging of brain ‘activity’ based on MR signal changes -Associated with metabolic and cerebral-blood-flow changes -Most common method is based on changes in Blood-Oxygen-Level-Dependent (BOLD) MR signal -Best spatial resolution
30
Is the hippocampus both necessary and efficient?
-Just a correlation -Doesn't tell you that the hippocampus is necessary or sufficient for memory
31
What is positron emission tomography (PET)?
-Involves injection of radioactive tracers that resemble compounds of biological interest -Uses dedicated tracers around the head -Tracers can be followed in brain e.g. to monitor metabolic activation -Tend to use MRI more now -Poor spatial resolution and costly
32
How can PET imaging be used to monitor brain activity and chemical neurotransmission?
-Can cause changes in Parkinson’s disease -Less DAT in striatum - reflects degeneration of dopaminergic fibres that express this transporter at terminals -More binding of dopamine receptor specific tracers - reflects less dopamine release that could displace tracer from receptor -Some regions are hypo, others hyperactive