Basics to know Flashcards
1
Q
Label these different viewing segments of the brain
A
2
Q
Label these orientations of the head
A
top down- horizontal
plane of face- coronal
side on view- sagittal
3
Q
Label the areas of the cerebral hemispheres
A
4
Q
Label the brain vesicles
A
Forebrain (telencephalon and diencephalon)
Midbrain (mesencephalon)
Hindbrain (metencephalon and myelencephalon)
5
Q
What are the folds in the cerebral hemisphere called?
A
Gyri
and the sulci are the grooves between the folds
6
Q
Name the 4 major subdivisions of the diencephalon
A
The four major subdivisions of the diencephalon include the thalamus, hypothalamus, subthalamus, and the epithalamus
7
Q
What is the central core of the cerebral hemisphere?
A
The diencephalon
8
Q
How many ventricles are there in the brain?
A
There are 4
2 lateral, 3rd and 4th ventricle
9
Q
Tell me about the organisation of the ventricles
A
The ventricles are continuous with each other and are filled with CSF
10
Q
What is the Ventricular size indicative of?
A
Ventricular size can be indicative of cortical atrophy (neurodegeneration)
11
Q
Whats associated with ventricular enlargement?
A
Neurodegenerative diseases
12
Q
What are ventricles filled with and where is this secreted from?
A
The ventricles are fluid filled with CSF
CSF is secreted from specialised capillaries called Choroid Plexus
The Choroid plexus line the ventricles
13
Q
Is ventricular size associated with psychiatric disorders as well as neurodegenerative diseases?
A
Ventricular size is hard to detect in psychiatric disorders which make them hard to observe. There are slight changes but they are at a very small level
14
Q
What are the cortical areas subdivided into?
A
Cortical areas are divided into lobes
15
Q
Name the lobes of the brain?
A
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
16
Q
What are the association cortexes?
A
Association cortex are the regions of the brain that aren’t assigned any specific function in the brain. This is about 90% of the brain. It is involved in integrating information based on past experience and memory. Taken to frontal lobe which then makes the executive decision
17
Q
Name the cortexes associated with each of the lobes
A
- Primary motor cortex
- Primary sensory cortex
- Visual cortex
- Auditory cortex
18
Q
Are the two hemispheres of the brain equal in size?
A
There is asymmetry between the cerebral hemispheres
19
Q
Label these sulci and gyri structures
A
20
Q
Whats the Corpus callosum?
A
A band of fibres that connects the left and right cerebral hemispheres
21
Q
How do the left and right cerebral hemispheres differ in their specialisations
A
Left is more specialised for verbal and linguistic tasks and right is for special (simple but what experiment showed)
22
Q
Tell me about how the lateralisation of the brain varies in patients with schizophrenia
A
Not the same lateralisation of brain function between left and right in patients with schizophrenia which could explain cognitive function lack
23
Q
What lobes are the following functional areas in:
- Motor lobe
- Sensory lobe
- Visual lobe
- Occipital lobe
A
Motor: Frontal lobe
Sensory: Parietal lobe
Auditory: temporal lobe
Visual: occipital lobe
24
Q
What is the role of the frontal lobe?
A
- voluntary movement
- expressive language
- managing higher level executive functions i.e., collection of cognitive skills like organisation, self motor, goal setting
25
Whats the roles of the **parietal lobe**?
* sensory perception and integration
26
Whats the roles of the **temporal lobe**?
* processing affect/ emotions
* language
* certain aspects of visual perception
* the dominant temporal lobe on the left, is involved in understabding language and learning and remembering verbal information
27
Whats the roles of the **occipital lobe**?
* Visual processing
* distance and depth perception
* colour determination
* face recognition
* memory formation
28
Whats the roles of the **motor cortex**?
This is a region of the cerebral cortex involved in the **planning, control and execution of voluntary movements**
Classically, the motor cortex is an area of the **frontal lobe** located in the posterior precentral gyrus immediately anterior to the central sulcus.
29
Whats the roles of the **sensory cortex**?
The sensory area of the brain recieves and processes sensory information
30
Whats the roles of the **Visual cortex**?
The primary purpose is to recieve, segment and integrate visual information
The processed information from this cortex is sent to other regions of the brain to be analysed and utilised
31
What are the roles of the **auditory cortex**?
This cortex plays a critical role in our ability to perceive sound
32
What did Roger Sperry recieve his nobel prize for in 1981?
Describe some ideas from this experiments and how that helped come to his conclusion
* Performed 'split-brain' experiments in 1959-1968 where he performed different experiments on cats, monkeys and humans with a severed corpus callosum
* He was studying the functional differences between the two brain hemispheres
* In cats and monkeys he found out that if the hemispheres werent connected then they would function independently of one another aka. split brain
* He found that the left hemisphere interpretated language whilst the right could only recognise language but could not interpret it
* **chemoaffinity hypothesis:** neurons make connections with their targets based on interactions with specific molecular markers
33
What is the main role of the **thalamus**?
Its a 'relay station' for sensory informaton
34
What is the relationship between the thalamus and the neocortex?
The thalamus provides all parts of the neocortex with **afferents,** and, in turn, the thalamus recieves input to the cortex
35
What is the neocortex?
The neocortex is part of the human brain's cerebral cortex where higher cognitive functioning is thought to originate from
36
What loop is the thalamus part of in the orbitofrontal cortex and what does this play a role in?
The **cortico-striatal-thalamis loop circuit**
This loop is important in controllling the input to the cortex
37
With sensory information such as touch, where does the thalamus project this sensory information?
The **Ventral posterior nuclei** relay information regarding touch and perception of bodily position to the **primary somatosensory cortex** in the **cerebral cortex**
38
What is the **Reticular activating system**?
This is a network of neurons that extends from the **medulla ---\> lower midbrain**
It carriers **non-specific** information about alertness and arousal
Its present in the brain stem
39
Tell me about **axon collaterals**
An axon typically develops side brances called axon collaterals
This is so one neuron can send information to several others
**Axon --\> Axon collaterals --\> terminal branches (each has a synaptic terminal on the tip)**
40
What is the **basal ganglia** involved in?
Extrapyramidal motor control and coordination
41
Label the structures of the basal ganglia...
42
Tell me the main roles that the basal ganglia has
* fine tuning of volunary movement
* intitiation of movement
* smooth execution of movement
43
What two features of the basal ganglia form the striatum and what is its appearance like?
The **Caudate and Putamen** form the striatum
They have **fibre tracks** along them which gives them a **stripy** appearance
44
Tell me about the appearance of the **Substantia Nigra** and why it is this way
The Substantia nigra is dark in appearance because it is where **melanin** is present
45
Lesions to the subthalamic nuclei can give rise to what condition?
What is the main characteristic of this condition?
Give rise to a condition known as **Ballismus**
This is where there are explosive movement of the limbs
46
The degradation of what pathway is involved with Parkinson's disease?
The degradation of the **substantia nigra- striatum pathway** (a dopaminergic pathway)
47
What is the **limbic system** and what three main structures are involved in this system?
The limbic system is involved in the origins of **emotional behaviour**
The main structures involved in this pathway are:
* Amygdala
* Hypothalamus
* Hippocampus
48
Label the limbic system...
49
What lobe is the amygdala, thalamus and hypothalamus in?
The temporal lobe
50
What is the hypothalamus involved in?
The origin of emotion
51
What is the amygdala involved in?
The process of fear and fear conditioning
Also involved in the emotional response to face recognition
52
Name a diseases that can cause lesions of the amygdala?
What happens in this diseases and what are the effects of this?
**Urbach-Wiethe disease**
Here calcium is deposited in the amygdala
If this disease occurs early in life, then these patients with bilateral amygdala lesions cannot discriminate emotion in facial expressions, but their ability to identify faces remains
53
Name three processes that the amygdala is involved in?
Reward
Addiction
Negative reinforcement (which is important in addiction)
54
What is the **reticular formation**?
A diffuse ascending network of neurons which regulate arousal
Interconnected nuclei throughout the brain stem
55
Tell me what the Ascending reticular activating system (ARAS) inputs to?
ARAS inputs to hypothalamus, basoforebrain and thalamus. Important for regulation sensory imput to the cortex
56
57
Name the main neurotransmitters involved in the brain
* **Noradrenaline**
* **Dopamine**
* **5-HT**
* **Glutamate**
* **GABA**
58
Draw noradrenaline
59
draw dopamine
60
draw 5-HT
61
draw glutamate
62
draw GABA
63
What type of neurotransmitter is noradrenaline?
A catecholamine
64
Tell me about the axons that noradrenaline travels along, what is it known as?
Noradrenaline travels along **long ascenidng axonal tracts**. These are known as the **medial forebrain bundle**.
65
Name the monoamines
dopamine, noradrenaline and serotonin
dopamine and noradrenaline are also known as catecholamines
66
What can monoamines influence hormone secretion from?
The pituitary
67
Where are the neurons present that synthesise noradrenaline?
The Locus Coeruleus (LC)
68
What pathways originate at the locus coeruleus?
Virtually all the Nadr efferent pathways originate at the LC
69
Where is the Locus Coeruleus present?
Tell me about the axons that branch off of this nucleus
This nucleus is in the **midbrain** and part of the **reticular formation** which has a role in the arousal, sleep/wake cycle
The axons consist of highly branches, largely **unmyelinated axons**
The axons innervate the **limbic system** and limbic areas of the **cortex** and innervate areas controlling the **sensory input** which has a key involvement in **perception and attentional processes**
70
What type of neurotransmitter is dopamine?
Catecholamine
71
What nucleus secretes dopamine?
Dopamine is synthesised in nerve cell bodies in the ventral tegmental area (VTA) and is released in the **nucleus accumbens** and the **prefrontal cortex**
72
What are the dopamine pathways?
Mesocortical pathway
Mesolimbic pathway
Nigrostriatal pathway
Tuberoinfundibular pathway
73
What are the dopamine nuclei?
substantia nigra
ventral tegmental area
arcuate nucleus of the hypothalamus
74
What main processes are each of the dopamine pathways involved in?
Nigrostriatal pathway: motor control
Mesolimbic and Mesocortical pathway: behaviour
75
What dopamine pathway is the nucleus accumbens important in?
Mesolimbic
76
What nuclei is important in the 5-HT pathway?
The **Raphe nucleii**
77
What does the Raphe nucleus innervate?
The limbic system and cortex
78
Tell me how neuronal activity changes in the 5-HT pathway in freely moving animals
in freely moving animals, the level of neuronal activity increases immediately prior to and during periods of activity
79
Where are the raphe nuclei found?
They are found in the medulla and are part of the reticular formation
80
Tell me about the **cholinergic pathways** axonal projections
They have long and short axonal projections
81
Cholinergic neurotransmission is mediated by what neurotransmitter?
Acetylcholine (ACh)
82
Tell me the link between the cholinergic pathway and the nucleus of meynert?
The nucleus basallis neurons project the cholinergic axons to the cerebral cortex and the septal cholinergic neurons to the hippocampus
83
Tell me the neurotransmitters involved in the excitatory and inhibitory transmission in the cholinergic pathways
What do they act on?
**Glutamate and GABA**
**Glutamate** is a fast **excitatory** NT that acts on two classes of receptors: Ligand gates ion channels (ionotropic) and G-protein coupled receptors (metabotropic)
**GABA** is an **inhibitory** NT and act on gated chloride channels
They are major transmitters in the CNS and have a ubiquitous distribution
84
Atrophy of what part of the brain is thought to be part of the pathophysiological cascade in progressive alzheimer's?
Severe atrophy of the basal forebrain cholinergic system especially of the nucleus basalis of Meynert (NBM) and an ensuing reduction of cholinergic innervation of the cortex are considered part of the pathophysiological cascade in progressive Alzheimer's disease (AD)
85
Label these structures of the cholinergic pathway
86
to revise neurotransmitter pathways, consult the Biochemical Basis of Pharmacology, Cooper Bloom and Roth.
to revise functional neuroanatomy. Brain Biochemistry by Philip Strange gives a simple and readable account.
Copies of both these texts are in the library.
87
What are the methods for studying CNS disorders?
**imaging techniques**
**Indirect ‘markers’ for changes in neurotransmitter function**
**Post-mortem studies on human brain**
**Genetic- linkage analysis**
**Animal models**
88
Look up the work of Nora Volkow and Victor Ramahchandrah
89
Tell me the different types of **imaging techniques**
Tell me their resolutions
* **CT** (computerised tomography)- X-ray
Spatial resolition several mm
* **MRI** (magnetic resonance imaging)
Resolution less than 1mm
* **fMRI** (functional magnetic resonance imaging)
* **Diffusion tensor imaging**
* **PET** (positron emission tomography)
* **SPECT** (single photon positron emission tomography)
* **EEG** (electroencephalography)
* **MEG** (magnetoencephalography)
90
What is fMRI?
What idea is it based upon?
This is a development from MRI
It detects changes in activity levels in the brain
This is based on the fact that Oxyhaemoglobin has different magnetic resonance to deoxyhaemoglobin
91
What is the basis for fMRI?
* Reveals patterns of actiivty in the intact brain
* Visual stimulation
* Activity utilises oxygen
92
Tell me about diffusion tensor imaging
Mapping pathways and investigating aberrant connectivity
93
What do PET and SPECT scans show?
Both of these techniques reveal activity in the intact brain
94
What is the main advantage of the SPECT scan?
Does not require on site cyclotron
95
Tell me how the PET/ SPECT scans work?
* first unstable positron emission isotopes are created in a cylcotron e.g. O15 (half-life 2 min)
* when these isotopes are injected, they distribute according to the relative activity of the brain regions (these isotopes bind to specific receptors)
alternately, this technique may be used to estimate receptor levels
96
Name some non-invasive imaging techniques
EEG and MEG
97
indirect 'markers' are used to detect changes in neurotransmission function. State some fluid which these markers can measure the level of metabolites in...
* Cerebrospinal fluid (CSF)
* Plasma
* Urine
* Platelets
98
How do markers measuring neurotransmitter function bind to platelets?
They bind using monoamine transporters as markers for depression (looking at 5-HT uptake)
99
Give an example of a binding used when lookin at post-mortem human brains
Radioligand binding
Radioligand binding is an approach that makes use of a radioactively labeled compound, which binds at the target binding site.
100
What are the disadvantages of the imaging techniques of looking at post-mortem studies on the human brain
* The protein is labile- may degrade
* Patients may have been taking medication
101
Tell me about **genetic- linkage analysis**
* restriction-fragment length polymorphisms RFLPs
* DNA is highly polymorphic (one variant every 100 bp) some of these occur at cleavage sites for restriction endonucleases-
* different sized DNA fragments are compared by electrophoresis
102
How are restriction-fragment length polymorphisms (RFLPs) inherited and what do they require?
* RFLPs are inherited in a **Mendelian manner**
* requires **family ‘pedigree’ of inheritable disease**- easiest to study in ‘genetically isolated’ communities
Mendelian inheritance: The manner by which genes and traits are passed from parents to their children. The modes of Mendelian inheritance are autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive. Also known as classical or simple genetics.
103
What do RFLPs determine?
determines whether inheritance of the disease and the RFLP are linked
104
Whats the pros and cons to genetic linkage analysis with RFLPs?
* this approach **worked well for mapping gene mutatio**n that is responsible for **Huntington’s** chorea
* less successful for **other disorders**- these may involve multiple genes or mitochondrial DNA
105
What are **animal models** used for?
To mimic neurochemical changes that occur in disease
106
Tell me what the animal models showed with Parkinsons disease
**Parkinson’s disease-**
* rat 6-hydroxydopamine lesions of the striatum
* primate MPTP lesions of the striatum
107
What are the pros and cons of using animal models?
**Advantages:** drug screening therapy
**Disadvantages:** not an exact ‘phenocopy’ of the disease
108
Genetic approaches?...
**Mouse**
Mice over-expressing mutant Alzheimer's disease (AD)-related proteins exhibit many of the neuropathological and behavioral features of the human disease. Transgenic animals have been created that express mutations in the amyloid precursor protein (APP), presenilin (PS)1, and PS2, and animals expressing more than one of these mutations.
**Invertebrate models of human disease**
109
**Summary**
**These two lectures provide intro for the rest of the course-**
* **You should be familiar with functional divisions of brain**
* **Neurotransmitters and pathways**
* **Methodological approaches**
* **Following lectures will cover;**
**Autism spectrum disorders**
**Depression and anxiety disorders**
**Psychotomimetic drugs**
**Schizophrenia**
**Reward and addiction**
