Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Systems Neuroscience > CNS development And Structure > Flashcards

CNS development And Structure Flashcards

(68 cards)

Start Studying
1
Q

What does the brain do

A

Senses environment and integrates information
Some things hardwired - breathing
Some aren’t - eg run to the train?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Brain function

A

Neuronal computation > output > real world interactions > input > neuronal computation

Adjust responses through learning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Hardwired example

A

Patella reflex
Hammer tap, tendon stretch, stretches sensory receptors in leg extensor muscle
Sensory neuron excites motor neurone in spinal cord and spinal interneuron, interneuron synapse inhibit motor neurone to flexor muscle
Motor neurone conducts AP to synapse on extensor muscle fibres causing contraction, flexor muscle relaxes due to inhibition
Leg extends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Sperrys experiment (1940s)

A

Frog: retinotopic map from retina
Direct connection optic tectum to motor cortex
Amphibians can regrow optic nerve if cut
Cut and rotate eye by 180, map did not reflect new sight as hard wired, inverted image and could not catch fly
Innate and based on initial distribution of chemical markers in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Plastic circuits

A

Learnt behaviours
Usually during critical period for easier learning
Neurodegenerative diseases effect learning and memory so related to plasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Are receptors different during development and adulthood

A

Yes
Biophysical properties different
Activated for different times, different processing
Activation threshold (long term potentiation) for memory formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

System development: Nature and nurture

A

Nature- hardwired eg migration, differentiation etc usually overshoot and then defined

Nurture- plasticity. Some synapses maintained and strengthened some lost based on experience

Experiences are key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neuroscience core concepts

A

1) NS controls and responds to body functions and direct behaviour
2) NS structure and function are determined by both genes and environment throughout life
3) the brain is the foundation of the mind
4) research leads to essential understanding for therapies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

NS system structure and function determined by both genes and environment throughout life

A

Genetically determined circuits are foundations of NS
Experiences change the NS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Experimental approach to systems neuroscience

A

What is the sensory stimulus? Complex or minimalistic?
What is the neuronal processing? Single cell resolution, cells of same type or neuronal networks?
What is the output? Motor output, neuronal firing, recall?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Visual perception

A

Neurone detects position
System will interstate all different inputs
Processing of image details

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Key areas of research related to systems neuroscience

A

Life long health
Nutrition for health
Biotech for health
Mental health
Neurodegenerative
Insight into living human brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Types of evidence

A

Correlation
Causation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Key elements of research

A

Grand question?
Model system?
Stimulus?
Outcome measure?
Correlation vs causation?
Remaining questions?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

System

A

A group of cells with a concerted function
In neuroscience_= info processing
Smell, heating, touch, memory etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Every function of NS is underpinned by circuit

A

Sensing changes in environment
Deciding what to do based on instinct and experience
Response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Early stages of brain development of vertebrates (frog)

A

Blastula
Blastocoele
Gastrula
Blastophore
Mesoderm
Neural plate

Great similarities in embryonic development across vertebrates
Time course differences tho (xenopus 6hrs humans 2 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Neurogenesis

A

Notochord, floorplate, and roofplate are transient structures essential for instructing nervous system formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Neurogenesis and differentiation

A

When and where neuron is born determines it’s fate
Morphogen gradients drive differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

3 primary brain vesicles in development

A

Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Adult derivatives

A

3 segments further differentiate to 5 secondary brain vesicles
Telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon
Further separate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do brain vesicles differentiate

A

Morphogenetic bind to receptors ti activate or repress sets of TFs
TFs (Hox genes) control programmes of gene expression
Gene expression profiles determine identity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Cranial nerve development

A

Develop from inner neural tube but part of PNS (except optic nerve as it remains in CNS)
Intermediate targets
Guidance cues (attractive/repulsive)
Fasciculation
Growth cone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Early development summary

A

Fertilised egg (zygote) divides
Morula forms
Blastocyst
Gasrelation - movement of cells towards midline creating primitive streak
Production of endoderm, mesoderm, ectoderm
NS develops from ectoderm, thickens and becomes neural plate
Neural groove due to uneven rates of cell division creasing midline of embryo
Forms neural tube which becomes cerebral ventricles of the brain and central canal with the spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Early development - neural cells
Progenitor cells of neural tube are precursor cells aka neural stem cells First step of neurogenesis Undifferentiated cells undergo mitotic divisions to produce stem cells or neural blasts that will differentiate into neurones Dividing precursor cells form ventricular zone Some leave ventricular zone and form marginal zone As it grows an intermediate zone forms where cells differentiate into neurones and glia 2nd stage - Greater distances so cell migration occurs via radial glia 3rd stage - differentiation into neurones 4th - process outgrowth
26
Prenatal brain development
Largely genetic control But nutrition and toxins can impact
27
Postnatal brain development
Experience depending Gene environment interactions
28
Are all connections worth keeping
No Overshoot Neurotrophic and electrical activity determine final pattern of contacts Compete for neurotropins and electrical input
29
Example of experience dependent development
Critical period of column dominance in visual system Input from eyes reaches the primary visual cortex (striate cortex) via LGN Layer 4 first intermingled and then ocular dominance columns during development One eye deprived - columns of good eye expands, bad eye columns shrink
30
Congenital cataract
Needs to be treated quickly
31
Amblyopia
Cover eye to make lazy eye work Earlier detected better treatment Untreated causes poor or blurry vision
32
Central nervous system
Brain and spinal cord Integration and analysis of info
33
Peripheral nervous system
Cranial nerves Spinal nerves Sensory and motor components
34
Cranial nerves
1 olfactory 2 optic 3 oculomotor 4 trochlear 5 trigeminal 6 abducens 7 facial 8 vestibulocochlear 9 glossopharyngeal 10 vagus 11 accessory 12 hypoglossal
35
Somatosensation
Receptor endings pick up stimulus Pain and temp afferent fibres make connection Mechanosensory enters dorsal root and joins dorsal column
36
Somatic sensory systems
Body Mechanical stimuli: dorsal column medial lemniscal system Face and anterior head Trigeminal somatic sensory system
37
The thalamus
Relay station Contains complete representation of somatic sensory periphery
38
Cortical maps of sensory surface
Sensory map exaggerates certain regions according to number/type of peripheral givers innervating a region Hands and face have the most/greatest Seen in animals too eg mouse whisker pad
39
Cortical integration and signalling
Thalamic input mainly layer 4 of cortex Cortex sends projections to limbic structures such as amygdala and hippocampus Cortex also sends descending signals (thalamus, brainstem and spinal cord) Eg ocular dominance columns in monkeys Barrels in primary somatic sensory cortex of ray of rat
40
Broadmann areas
Subdivided cortex into distinct regions based on gross anatomy and cytoarchitectural studies Imaging studies - characteristics reflected systems contributing to specific functions
41
Human brain
Neuronal and non neuronal cells in the brain proportionate Brain tissues - neurones (excitatory and inhibitory), glia (astrocytes, microglia, Oligodendrocyte, NG+ cells) Other influences - EMC, vasculature, ependymal cells
42
Tripartite synapse
Pre synapse Post synapse astrocyte - buffers k+, recycle glutamate
43
Barrel cortex development
P0-2 thalamic axons invade layer 4 P3-5 barrels become evident P7 local inhibitor projections formed P7-14 reduction in LTP in corticothalamic synapses
44
Glial cell development matches development of neural circuits
First neurones Then glial cells
45
Barrel cortex somatotropic map
Whisker pad matches barrels in the brain (each whisker is one barrel)
46
Whisker signalling pathway (ascending)
Mechanogated ion channels in nerve endings of sensory neurons Innervate hair follicle AP fires in sensory neurones trigeminal nerve Sensory neurons make excitatory glutamatergic synapse in trigeminal nuclei of the brain stem Trigeminithalamic neurones in principle trigeminal nucleus organised into barralettes - each receiving strong input from a single whisker
47
Whisker signalling from periphery to barrel cortex
Principle trigeminal neurones to ventral posterior medial nucleus of the thalamus VPM neurones respond rapidly and precisely to whisker deflection with one principal whisker evoking stronger responses that others VPM neurone to primary somatosensory neocortex Target = layer 4 barrel map
48
Primary function of neocortex
Generate associations of different sensory inputs which are processed in highly context dependent manner
49
Fgm8 - morphagen
Control - normal barrel field Anterior- move barrel field Posterior - expand structure
50
Barrel cortex is plastic (development)
Lesion of whisker follicles before day 4 prevents formation of corresponding barrels, changing the anatomical map in new born mouse
51
Arrival of axons in whisker pad development
WP first TG PrV VPM S1 last And then everything refunded basically post nataly
52
When is the map of whisker pad fixed?
Within a few days of birth Lesions have little effect after on map So early critical period Refinement of maps guided by activity dependent mechanism Experiences influence physiological properties of neurones
53
Cortical integration and signalling
Thalamic input predominately layer 4 recieved by spiny stellate and pyramidal neurones (excitatory) Descending outputs outnumber ascending ones
54
L4 dendrites
Input from thalamus Excitatory and inhibitory
55
L4 axons
Innervate layer 2/3 dendrites and axons
56
Interneurons
Inhibitory neurones Grouped by morphology, connectivity, mastheads and intrinsic properties Loads of cross talk so categories difficult Some have electrical synapses Close proximity and junctions needed Fast spiking cells that are most prominent inhibitory neurones in cortex and control AP generation
57
Cortical interneurons
Have different origin Born in ganglionic eminences and migrate tangentially and populate layers
58
P7
Local inhibitory projections are formed
59
P14
Feedforward inhibition and low intracellular cl concentrations So inhibitory projections match more to glial system development
60
GABAa receptors are selective for cl-
Early in development cl- concentrations are higher inside neeurones Neurons mature KCC2 synporter expressed and lowers cl- concentrations So during development GABA are actually excitatory due to concentrations
61
Inhibition helps to localise them integration of signals into columnar fashion
Voltage sensitive dye imaging Confinded to column L4 dendrites to Axon to L2/3 dendrites yo axons
62
How is thalamicirtical feedforward inhibition in spiny Stellate cells mediated
Small number of fast spiking interneurons that dampen activity Reduced subsequent excitation so synchronisation so changes charge in cell and probability that it will be excited again So depol and hyperpolerisation at the same time so integrates info
63
Inhibitory neurons essential in all neural networks
Visual system to V1 Both excitatory and inhibitory inputs shape response to stimuli
64
Modifying GABAnergic inhibition impacts critical period plasticity in mice
Plasticity can be delayed by preventing maturation of GABA mediated transmission Critical period brought forward by enhancing GABA transmission (eg with benzodiazepines)
65
Sensory perception
Subjective Created by neuronal activity eg vase vs 2 faces, light and dark etc
66
Experimental investigation of sensory perception in humans
Sensory stimulus (vase vs faces) Neuronal computation if sensory perceptive Behaviour report by motor output i saw 2 faces etc” so correlated
67
Experimental investigation of sensory perception in animals
Whisker detection task Model organism for brain studying Immobilised on magnetic platform Activate whiskers and measure brain activity C2 Whisker activated, tongue out, reward and trained with this Membrane potential correlates perception (correlation) Opogenetic programming of behaviour Activate that area induces linking don’t need to stimulate whisker S1 is necessary for detection of task Control, injection, recovery Inhibit it kill response, block glutamate receptors (is activation needed if inhibitors necessary) (causation)
68
Late depol contributes to perception
Causation Inhibit late or early response Inhibit early then block response Inhibit early block response So causation

Systems Neuroscience (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions