communication between neurones (3) Flashcards
what is a ligand
a chemical that interacts with a receptor
what is the binding site
the place on the receptor where the ligand interacts with the receptor
what is affinity
how well a ligand binds to a receptor
what does it mean if a ligand has a high affinity
almost all ligands bind to receptors
what are the types of receptor
ionotropic and metabotropic
what is an ionotropic receptor
where the receptor is directly coupled to an ion channel
what happens when a ligand binds to an ionotropic receptor
the ion channel opens
what happens when a ligand binds to a metabotropic receptor
the ligand binds to the outside of the postsynaptic membrane, changing the 3D the shape of the receptor; this activates G proteins and initiates a complex cascade of intracellular signals
what are the 2 types of NT
amino acid derivates and monoamines
what type of NT is glutamate
amino acid derivate
what amino acid does glutamate derive from
glutamic acid
is glutamate excitatory or inhibitory
excitatory
what type of NT is GABA
amino acid derivate
is GABA excitatory or inhibitory
inhibitory
what type of receptor do monoamines usually bind to
matabotropic
what are 2 types of monoamine NT
dopamine and serotonin
what are neuropeptides
proteins that act as NTs
what are examples of neuropeptides
opioids
what is fMRI most commonly used for
to see what parts of the brain we employ when carrying out a task
how does fMRI work
When more blood flows to a part of the brain, the amount of oxygenated haemoglobin in the area changes, which has a magnetic signature we can pick up with fMRI
how does EEG work
- Electroencephalography picks up electrical signals on the surface of the scalp
- Measures electrical activity within the brain via electrodes using a skull cap
- Scan recording represents brainwave patterns generated by activity of neurones
what is better about EEG than fMRI
high temporal resolution (better than fMRI), so we can see activity in the brain as a direct response to the stimulus
what is worse about EEG than fMRI
EEGs produce much more generalised information, so we cannot distinguish between activities originating in adjacent locations
how does MEG work
- As we think, neurones fire action potentials and create pulses of electric currents, which in turn generate weak magnetic fields
- MEG has a helmet lined with sensitive sensors (squid devices) which record the location and intensity of the magnetic fields
how does intra-cranial electrophysiology work
- recording electrodes are implanted into the brain
- These electrodes can record individual action potentials from single neurones
what is the idea of synaptic plasticity
- The response changes; the argument is that the response changing is a fundamental property of how our brains learn
what is long-term potentiation
we have a memory of the experience, and so the original input results in an enhanced output
