3-Neuroscience Flashcards
Dualist framework
person who created it + definition
René Descartes
The brain acts as the link between mental processes and the body
Neuron anatomy
zones + structures in each
Receptive zone
- Dendrites
- Cell body
Transmission Zone
- Axon
- Axon terminal
- Terminal boutons
Dendrites
purpose/function
- reach out to neurons
- receive signals
Cell body (neuron)
purpose/function
- carries genetic info (nucleus)
- maintains structure
- provides energy
Axon
purpose/function
- transmits signal
- varies in length (cm to ft long)
Axon Terminal + Terminal Boutons
purpose/function
- reach out and connect to other neurons
Action potential
trigger: effect on EP –> effect on channels
- Stimulus: increase EP –> Na channels open
- Na enters cell: EP increases to +ive –> K channels open
- K leaves cell: EP still rising –> Na channels close
- K continues to leave cell: EP decreases just below resting potential –> K channels close
- Sodium potassium pump and Leak potassium channels return EP to baseline
Action Potential
important voltages name + value
- 70mV: Resting potential
- 50mV: Threshold for action potential
Refractory period
types + events under this period
Absolute RP: impossible to trigger another AP
- Na or K channels are opened, cannot be reopened
Relative RP: another AP is possible but more difficult
- larger stim needed as EP is below resting potential
- OR EP is below threshold but K channels still open
message encoding
via action potentials
messages encoded via frequency of action potentials, not intensity
Glial cells
purpose
Help neurons with:
- structural support
- nourishment
- insulation
Myelin sheaths
description + purpose + types and their location
cells which coat segments of the axon
- allow for faster conduction of AP’s through saltatory conduction
CNS: Oligodendrocytes
PNS: Schwann cells
Nodes of Ranvier
description + purpose
uncovered segments of axon between myelin sheaths
- limit where ions from APs can diffuse in and out
Synapse
description + purpose
junction between presynaptic and postsynaptic neuron
- where communication between neurons occurs
Anatomy of a synapse
major structures + important structures within them
- Presynaptic neuron
- vesicles containing NT’s
- Synapse & synaptic cleft
- Postsynaptic neuron
- receptors
Steps for neurotransmission
across a synapse
- AP triggers vesicles containing NT’s to fuse with cell wall
- NT floats in synaptic cleft
- NT binds to postsynaptic receptor
- transmission continues via excitatory or inhibitory post synaptic potential
Methods of neurotransmission
types + description + purpose
EPSP (excitatory PSP)
- Depolarization: modify ion channels to increase EP in next neuron. eg: allow Na in
- makes AP easier or triggers AP
IPSP (inhibitory PSP)
- Hyperpolarization: modify ion channels to decrease EP in next neuron. eg: allow Cl in
- makes AP more difficult to trigger
PSP: post synaptic potential
Neural Development
Neural differentiation
Neuron Maturation
3 facts about it
- neurons mature by connecting with other neurons
- only connected neurons survive
- # of synapses peaks at 1 year old
Neuraxis
6 terms
Rostral - Caudal: towards frontal lobe - towards brain stem
Ventral - Dorsal: towards the stomach/chin - towards the back/top of the head
Medial - Lateral: towards - away from the midline of the body
Neuroimaging techniques
2 basic categories
Structural
Functional
Lesion studies
description + benefits and drawbacks + 1 example
analysing the impact of damage to a region of the brain
- find a direct cause and effect
- injuries aren’t precise and we cannot ethically damage a human’s brain
Phineas Gage: injury to frontal lobe caused major behavioural changes
Targeted electrical stimulation
description + purpose
single cell stimulation (electrical impulse to one neuron)
- helped map behaviour to specific brain regions
Single cell recording
description + purpose
electrode placed directly next to neuron (thin needle in the brain)
- records firing pattern of the neuron in response to a stimulus
structural imaging techniques
types + description + purpose
CT scan: X-ray images of XY slices of the brain
- best for quick, cheap and low res images
MRI: magnetic fields align H atoms to locate tissues
- best for high res images but slower and pricier to obtain
CT: Computed Tomography
MRI: Magnetic Resonance Imaging
functional imaging techniques
types + description + purpose
PET: radioactive tracer injected (glucose or O2), scan shows map of where tracers are being used
- determine metabolic activity of regions but injection is invasive, not temporally accurate
fMRI: measures blood oxygen levels in regions of the brain
- determine metabolic activity of the brain but not temporally accurate
EEG: records electrical activity of neuron populations through electrodes on the scalp
- time sensitive and not invasive
PET: Positron Emission Tomography
EEG: Electroencephalogram
3 broad regions of the brain
- Hindbrain
- Midbrain
- Forebrain
Hindbrain
overall purpose + structure names
Mostly for regulation of vital bodily functions
Reticular formation
Cerebellum
Medulla
Pons
Reticular formation
basic purpose
Role in:
- circadian rhythms
- arousal
- motivation
- posture and balance
Cerebellum
basic purpose
coordinated and fine movements
Medulla
basic purpose
regulates:
- breathing
- digestion
- heart rate
- autonomic reflexes
Pons
basic purpose
Role in:
- movement
- auditory perception
- emotional processing
Midbrain
overall purpose + regions + structures
Perception, arousal and motor control
Tectum:
- Superior colliculus
- Inferior colliculus
Tagmentum:
- Red nucleus
- Substantia Nigra
Tectum
structures and purpose
Superior colliculus: visual perception
Inferior colliculus: auditory perception
Tegmentum
structures and purpose
Red nucleus: role in motor control
Substantia Nigra: reward related behaviours via release of dopamine
Forebrain: subcortical sections
basic purpose + labels
Emotion, memory, perception, thought
Limbic system
- Hypothalamus
- Pituitary gland
- Thalamus
- Amygdala
- Hippocampus
Hypothalamus
basic purpose
- stress response
- energy metabolism
- hormonal control
Fight, Flight, Feeding, Fucking
Pituitary gland
structures + basic purpose
Anterior pituitary: hormones for
- thyroid
- testes/ovaries
- adrenals
Posterior pituitary: extension of the hypothalamus
- oxytocin
- vasopressin
Thalamus
basic purpose
central relay for axons, all senses synapse here EXCEPT our sense of smell
Amygdala
basic purpose
Role in emotional processing, especially fear responses
Hippocampus
basic purpose
- hold short term memories
- involved in transferring short term to long lerm memory
- spatial mapping of the world
- neurogenesis (even in adulthood)
Forebrain: Cerebral cortex sections
labels
Lobes:
- Frontal
- Occipital
- Parietal
- Temporal
bumps and grooves in the brain
terms
Gyri: bumps/ridges
Sulci: grooves/indents
Fissures: deep grooves often separating lobes
Occipital lobe
location + role + subsections
Caudal and dorsal (back of the brain)
Visual processing
Sections:
- primary visual cortex
Notable Fissures and Sulci
labels + locations
Sylvian fissure: seperates temporal and frontal lobes
Longitudinal fissure: seperates left and right hemispheres of the brain
Central sulcus: seperates frontal and parietal lobes
Temporal lobe
location + role + subsections
Lateral, by the ears-ish
Further visual processing, auditory processing, partially responsible for memory and language processing
Sections:
- primary auditory cortex
- Wernicke’s area (left side)
Parietal lobe
location + role + subsections
Top, middle of the head, down the sides slightly
Touch processing, spatial representations (orientation…)
Sections:
- primary somatosensory cortex
Frontal Lobe
location + role + subsections
Rostral, forehead and top of head area
Motor processing, decision making and higher order thought
Sections:
- primary motor cortex
- broca’s area (left side)
Brain laterelization
definition
When a function is specialized on one side of the brain
Broca’s area
purpose and location
Left side of the frontal lobe
Motor production of speech
Wernike’s Area
purpose and location
Left temporal lobe
Language comprehension (through hearing)
Types of language aphasia
names + damaged region + effects
Expressive aphasia: damaged Broca’s area –> lacks the motor control for speech
Receptive aphasia: damaged Wernicke’s area –> cannot comphrehend speech
Corpus callosum
location + purpose
thick segment of neurons connecting the L and R hemispheres, medial
carries info between the two hemispheres
Split brain syndrome
cause + effects
Severed corpus callosum –> independently operating hemispheres, some effects:
- cannot verbally name an object seen by the left visual field as the left hemisphere will not see the object
