Biology Unit 4.6 - Neuroscience Flashcards
What is electroencephalography (EEG)?
Detects voltage flucuations in the brain’s electrical activity over time through electrodes placed on the scalp
What are the advantages/disadvantages of an EEG?
+Non-invasive, no claustrophobia or staying still, no radioactivity or magnetic fields
-Only detects activity in the cortex
What is computerised tomography (CT)?
Use X-rays to show the internal structure of the brain in slices, from any angle
What are the advantages/disadvantages of CTs?
+Fast results for the whole body, can look at areas from different angles
-Use X-rays, images not as clear as MRI, only shows structural features
What is magnetic resonance imaging (MRI)?
Strong magnetic field and a radio wave pulse manipulate protons in water to give a 3D coloured map of the cerebral cortex
What are the advantages/disadvantages of MRIs?
+More sensitive than CT with good contrast, no radiation involved
-Claustrophobic and noise, patient needs to be totally still, can’t be used on patients with pacemakes or cochlear implants due to strong magnetic fields
What is functional magnetic resonance imaging (fMRI)?
Fundamentals of MRI are used to show flow of oxygenated blood, allowing structure and functioning of the brain to be assessed from second to second
What are the advantages/disadvantages of fMRIs?
+Shows what regions of the brain are most active, therefore functioning
-Claustrophobic and noise, patient needs to be totaly still, can’t be used on patients with pacemakers or cochlear implants due to strong magnetic fields
What is position emission tomography (PET)?
Metablosim of a radioactive isotope with a short half-life shows areas of glucose use
What are the advantages/disadvantages of PETs?
+Shows functioning of areas of the brain
-Uses gamma radiation
What occurs during brain development?
Formed in early embryonic development from the neural tube, which expands at the anterior end to form the brain, until the cerebral hemispheres can be identified by week 5 of gestation
During cerebral hemisphere formation, neural tube cell rapidly divide until they differentiate into neurons and glial cells, which make up the central nervous system
Neurons migrate to form the different structures of the brain, branch off to form synaptic communications with each other, while glial cells increase in number until adolescence, whereas neurons stop forming at birth
What are neural circuits?
Groups of interconnected neurons that connect different parts of the brain
Change, in three possible ways, when new information is aquired:
* Synapse is formed or lost
* Change in the amount of neurotransmitter released at a synapse
* Post-synaptic neuron response is changed
Reinforced by constant exposure to the information or experience that created them, and regress when the information or experience is no longer encountered
What is neuroplasticity?
The brain’s ability to form new connections between neurons in response to new information, sensory stimulation, development or damage
Allows the brain to change and adapt throughout life
What is developmental plasticity?
Process of change in neural connections, resulting from environmental interactions and learning, which is most prominent during the critical period
As development continues, unused connections are lost via synaptic pruning, which mostly occurs in adolescence and increases efficiency in the transmission of impulses
What is gene expression?
Parts of the genome are activated and deactivated a specific times and locations by chemical reactions, which may be behind many brain functions
Abuse is often linked to a higher risk of mental illness, where those who experienced the abouse finding it harder to recover from mental illness and be more likely to abuse alcohol and drugs
