Neuroscience Flashcards
Descartes
separated the mental processes of the mind from the physical processes of the brain - sees the mind as a separate entity existing outside the biology yet in control of our actions and thoughts
Neurons
fundamental building block of the nervous system
specialized for communication
organized into signalling pathways to communicate via synaptic transmission
Receptive Zone of the Neuron
receives signals from other neurons (dendrites)
- dendrites branch from the cell body
- reach out to other neurons and receive signals to be relayed to the dendritic branch of the cell body where some signals will be conveyed down the axon
Transmission Zone of the Neuron
pass on signals to other cells (axon and terminal ends)
The Axon
once a neuron receives a signal in the receptive zone, it is passed down a long fibre called the axon
- varies in length
- approaching the transmission zone at the end of the are the terminal ends
Terminal Ends
at the end of the transmission zone
reach out to make connection with the receptive zone of nearby neurons
Glial Cells
provide structural support, nourishment and insulation for the neuron
Cell Membrane
selectively permeable
separates the intracellular fluid from the extracellular fluid
Resting Potential
each of the ions contain either a positive or negative charge
the starting baseline for the differing concentrations of ions produces an electrical imbalance between the outside and the inside of the neurons
-controlled by 2 forces
–70mv inside the cell compared to the outside
Diffusion
the tendency for molecules to distribute themselves evenly in a medium
Electrostatic Force
the repulsion between ions with the same charge
Leaky Channel
allows potassium (+) to pass through the cell membrane (at all times) out of the neuron as they are drawn to the negatively charged protein (-) molecules
Voltage Gated Channels
stays closed during resting potential
Dorsal
refers to the back side of the axis
- to the top at level of the head
- to the back at the level of the spinal chord
Ventral
means to the front or to the belly
Rostral
top of the axis
Caudal
bottom of the axis
Medial
central/midline (in the brain)
Lateral
towards the outside (of the brain)
Lesion Studies
case studies of accidental brain injury - link anatomy with cognitive and behavioural deficits that occur
Phinneus Gage
the victim of a tragic railway accident - iron rod went completely through left cheek and top of skull
- survived and almost recovered completely
- major behavioural change - went from optimistic and lively to selfish and profane, erratic and unreliable
Advantages of Lesion Studies
a direct measure to a brain structure’s function
Disadvantages of Lesion Studies
hard to selectively target particular regions and draw conclusions
-can be overcome by studying legions in animals
Ablation Studies
researcher destroys/removes/inactivates a certain region of the brain and observes result in behaviour
Penfeild
used the stimulation and single cell recording technique - electrically stimulate an area and observe result to build an anatomical map
-Montreal Procedure
CT Scans
take a series of X-ray slices of the brain and piece them together to produce a picture
- helpful in diagnosing brain injuries
- limited by low resolution (can’t examine fine brain anatomy)
MRI
powerful magnetic fields are generated and align the hydrogen atoms in the brain
-can localize tissue when aligned
Structural Neuroimaging
used for a larger scale
- CT Scans
- MRIs
Functional Neuroimaging
PET Scans
fMRIs
EEG
Position Emission Tomography (PET)
how brain function relates to cognitive tasks
- a radioactive tracer is injected into the blood stream
- detects it in brain’s metabolic processes
- more active brain areas will use more metabolic processes
- relative patterns of activity can be constructed
- limited because it requires radioactive tracer to be injected which is invasive
Functional Magnetic Resonance Image (fMRI)
can produce a relatively clear image of a brain;s activity without radioactive tracers
measures the blood-oxygen dependent signal and uses the same principles as the MRI
measures the relative use of oxygen throughout the brain
more active = more metabolic resources
Limited because it only produces a rough image of brain activity and timing is off
Electroencephalogram (EEG)
cap of sensitive electrodes record electrical activity in the brain through the scalp
rough image of overall activity from populations of neurons
can be more informative - averaging out signals across many repeated trials, noise can be balanced out and the consistent effect on the read out by the specific repeated stimulus during ERP remains
-ERP can be hard to interpret but certain markers can signify different types of neural processing
Hindbrain
region at the base of the brain that connect the brain the the spinal cord
- medulla, pons, reticular formation, cerebellum
- primarily involved in the regulation of vital bodily functions
Medulla
most caudal part; lies directly above spinal cord
-breathing, digestion, regulation of heart rate
Pons
rostral to medulla
- relays info about movement from the cerebral hemispheres to the cerebellum
- contains nuclei that are generally part of the reticular formation
- processes some auditory info and thought to be involved in emotional processing
Reticular Formation
a set of interconnected nuclei found throughout the hindbrain (excluding cerebellum)
Ascending Reticular Formation
arousal and motivation, and part of a large network responsible for conscious experience
- circadian rhythms
- damage leads to loss in brain function (or even coma)