Neuroscience 2 Flashcards
Neuraxis
Human nervous system axis
Dorsal & ventral
- At the level of spinal cord
- At the level of the head
- SPINAL CORD
Dorsal = back
Ventral = front - HEAD
Dorsal = up
Rostral & caudal
Rostral - to the top of the axis
Caudal - towards the bottom of the axis
What do brain injuries link?
Brain anatomy with behavioural deficits
Special techniques exist for studying the __________ and ________ of the brain
Special techniques exist for studying the STRUCTURE and FUNCTION of the brain
What are the 2 techniques to study the structure and function of the brain?
Lesion studies and targeted electrical stimulation
Techniques to study the structure and function of the brain:
Lesion studies
Lesion studies must be specific to target the function of a brain region
ADV - a direct measure of a brain structure’s function
DISADV - hard to selectively target particular regions and draw conclusions
SOL - Specific brain lesions can be studied in animal models
Techniques to study the structure and function of the brain:
Electrical stimulation
Targeted electrical stimulation can also provide insight on brain function
- electrically stimulates an area of the brain and observes the result on behaviour to build an anatomical map related to the function
- single cell stimulation helped map behaviour to specific brain regions
- single cell recording reveals the function of individual neurons
- the pattern of firing reveals a particular neuron’s functional role
Computed Tomography (CT)
CT scans produce structural slices of the brain
- those x-ray lives of the brain are pieced together to produce a quick and inexpensive picture of the brain
- helpful to diagnose brain injuries
Problem with CT scans
Low resolution –> difficult to examine fine brain anatomy
- thus not often used in neuroscience research
Magnetic Resonance Imaging (MRI)
Used for more detailed structure image of the brain
- provides higher resolution images of the brain
- takes much longer and more expensive
- powerful magnetic fields are generated which align the H+ atoms found throughout the brain
- while the atoms are aligned, MRI can be used to localize tissue very precisely throughout the brain
Positron Emission Tomography (PET)
Display the functional role of brian structures
- a radioactive tracer of glucose or oxygen is injected into the bloodstream
- the radioactive molecules make their way to the brain and are used in metabolic processes which are detected by the PET scan
- the more active brain area will use more metabolic resources thus an image of the brain’s relative pattern of activity can be constructed
Functional neuroimaging techniques examples
PET, FMRI
Structural neuroimaging techniques examples
CT and MRI
Disadvantage of PET
Requires a radioactive tracer to be injected
- a relatively invasive procedure
Functional Magnetic Resonance Imaging (FMRI)
Often the preferred functional neuroimaging technique b/c it can produce a relatively clear image of the brain’s activity without the need for a radioactive tracer
- uses many of the same principles as MRI
- able to measure the relative use of O2 throughout the brain under the same basic assumption as the PET scan
What does FMRI measures?
The blood oxygen dependent signal
Disadvantage of FMRI
FMRIs provide temporally imprecise mapping of brain function
The images look striking but the oxygen used by the brain often spikes a few seconds later than the spikes of the functional activity in the brain
Electroencephalogram (EEG)
Displays the activity from specific populations of neurons
- EEG records from a population of neurons to provide only a rough image of the brain’s overall activity
- in an event created potential (ERP) experiment, a specific stimulation is presented to the participant repeatedly while the EEG is recording
- the EEG will generally produce very noisy waves, the specific stimulus presented can have a small and consistent effect on the readout
- by averaging the signal across many trials, the noise can be balanced out and a characteristic signal will remain
*when combined with the behavioural measure, EEG and ERP signals can be highly informative markers with very precise temporal resolution
What are the 3 groups of the brain
Forebrain, midbrain, hindbrain
What does the hindbrain connect?
Connects the brain to the spinal cord
The hindbrain consists of what?
Medulla
Pons
Reticular Formation
Cerebellum
*RCMP - the hindbrain is primarily involved in the regulation of vital bodily function
What does the medulla regulates?
Regulates breathing, digestion, HR, autonomic reflexes (eg. sneezing)
What are the roles of pons?
Role in movement, auditory perception, emotional processing
What are the roles of reticular formation?
Role in arousal, motivation, circadian rhythms, posture and balance
What does the cerebellum facilitate?
Coordinated movement
What does the midbrain process?
Processes perception, arousal and motor control
What are the 2 major subdivisions of the midbrain?
Tectum and tegmentum
What are the 2 structures involved in functions related to perception and action that are part of the tectum?
Superior colliculus and inferior colliculus
What is the superior colliculus involved in?
Thought to be involved in eye movement and visual reflexes
*vision is superior thus superior colliculus
What is the inferior colliculus involved in?
Thought to be involved in auditory integration
*audition is inferior thus inferior colliculus
What does the tegmentum include?
Red nucleus and substantia nigra
What does red nucleus do?
Contributes to motor control
*Motor units involve muscles - muscles are red thus red nucleus control motor units
What does substantia nigra do?
Plays an integral role in reward-related behaviours through the release of the neurotransmitter dopamine
What does the forebrain control?
Complex functions (eg. emotions, thoughts, perception and memory)
What does the hypothalamus do?
Control stress response, energy metabolism, hormonal control
- Controls fight, flight, feeding and reproduction
Where is the pituitary gland located in regard to the hypothalamus
Inferior to the hypothalamus
- very small
What is pituitary gland?
The master gland of the endocrine system
What are the 2 subregions of the pituitary gland?
Anterior pituitary and posterior pituitary
Anterior pituitary
- Receives signals from the brain (usually via hypothalamus)
- Releases stimulating hormones to regulate other important endocrine glands
Posterior pituitary
An extension of the hypothalamus and releases 2 hormones (oxytocin and vasopressin)
What are the 2 hormones released by the posterior pituitary?
Oxytocin and vasopressin
What is oxytocin involved in?
Involved in basic physiological functions (eg. lactation) and plays a role in bonding, love and trust
What does vasopressin regulate?
Vasopressin is a vital blood hormone that regulates levels of thirst by interacting with the kidneys to regulate glucose levels
What is the relay station of the cortex?
The thalamus
What is the one exception that bypasses the thalamus?
Olfaction - sense of smell
What is the amygdala?
A symmetrical almond-shaped structure located just below the surface of the temporal lobe
What does the amygdala do?
Receives sensory info and plays a role in decoding emotions, particularly stimuli that may be threatening
- Decodes fear and emotion from sensation
What is the hippocampus?
Horse shoe shaped structure in the temporal lobe
What is the hippocampus involved in?
Involved in the process of memory and navigation
What is the hippocampus connected to?
Connected with the amygdala
- might be why strong emotions may be triggered by particular memories
Hippocampus: memory
- activity in the hippocampus is related to your ability to hold short-term memories
- may be involved in the process of transferring to long-term memory
Hippocampus: navigation
maintain a spatial map of the world around you
____________ continues throughout adulthood in the hypothalamus
Neurogenesis
- facilitates hippocampal memory function across the lifespan
Neurogenesis
The birth of new neurons
The ___________ system is highly interconnected and complex
The limbic system
What does the cortex control?
Info processing and cognition
What does the cerebral cortex refers to?
Refers to the outer layer of the brain
_____ and _____ greatly increase the surface area of the cortex
Gyri and sulci
Gyri
A ridge on the cortex or a bulge outwards
- often linked to specific mental functions
Sulci
An indent or gap between gyri
- useful in indicating where the neural tissue responsible for one function ends and next function begins
Fissures
Very deep sulci
- often divide major areas of the cortex responsible for distinct mental processes
What are the 4 lobes of the brain?
Frontal lobe - lies at front of brain
Occipital lobe - lies at the back of the brain
Parietal lobe - between the front and occipital lobes
Temporal lobe - wraps around both sides of the brain
What does the occipital lobe process?
Processes vision
- contains the *primary visual cortex
What does the temporal lobe process?
Processes visual form (higher visual processing), audition, memory and language
- contains the *primary auditory cortex
What does the parietal lobe process?
Processes touch and spatial location
- directly along the central sulcus (at connection point with the frontal lobe) lies the *primary somatosensory cortex
- contains a spatial representation of the world
What does the frontal lobe process?
Processes decision-making and higher order thoughts
- along the central sulcus (where frontal meets with parietal lobe) lies the *primary motor cortex (where motor commands originate)
Brain lateralization (aka asymmetry)
Function that specializes to one side of the brain
Language processing appears to be lateralized to the _______ hemisphere
Left hemisphere
Expressive aphasia
Due to the Broca’s Area - motor production of speech
Receptive aphasia
Due to the Wernicke’s Area - language comprehension
What joins the two hemispheres of the brain together?
Corpus callosum
- carries info b/w the two hemispheres of the brain
What leads to Split Brain Syndrome?
A severed corpus callosum
- split brain patients can’t communicate b/w their two hemispheres
Biological predisposition to learn through _____________ behaviours
Modeling
Theory of mind
The ability to attribute mental states — beliefs, intents, desires, emotions, knowledge — to oneself, and to others, and to understand that others have beliefs, desires, intentions, and perspectives that are different from one’s own
Motor neurons respond to _________-____________
Self-actions
Mirror neurons respond to actions of ____________
Actions of others
- you fire APs as someone else does the action
How we recognize others?
Recognition (of their face) & emotional significance (emotional connections)
Capgras Delusion
AKA the imposter syndrome
- The ability to explain why you recognize someone but don’t have any emotions towards them
Hemi-spatial neglect
Ignoring half of the world
- Most of the time, they only pay attention to the right side of their life
- Shows damage to parietal lobe
- It’s an attentional issue, not visual
