1.3 Neural communication Flashcards
What are growth cones?
grown of neurons in developing brains
What is neuroplasticity?
dynamic morphology of growing neurons
What did Charles Sherrington postulate?
functional junctions existed between neurons
What were the observations that Sherrington based his postulation on?
- degeneration of NS always resulted in discrete, demarcated pattern of loss, rather than diffuse
- reflex response were much slower than explicable by the speed of nerve conduction (so, delay from neuron to effector)
- reflex conduction is unidirectional
What did Loewi discover?
able to mimic effects of sympathetic and parasympathetic nerve stimulation by applying fluid from stimulation to another non-stimulated heart
ACETYLCHOLINE DISCOVERED
What is a neurotransmitter?
when reaching AP terminal, neurotransmitter specific receptors recognise and initiate next step of transmission on postsynaptic cell
What are chemical synapses?
energy dependent process take place there (ie. synthesis, release, reuptake)
How fast is transfer of chemical synapse?
slow, due to complex energy dependent release, machinery, diffusion
What usually causes nerve impulse via depolarisation?
neurotransmitters binding onto the postsynaptic neurotransmitter receptor
What are electrical synapses?
show direct electrical connections between neurons seen at gap junctions
What do electrical synapses cause/
excitation (can’t choose between excitatory and inhibitory) on postsynaptic cell
What kind of transmission happens in electrical synapses?
passive transmission, no energy-dependent processes
How fast does transmission in electrical synapses occur?
fast with no latency
What are some benefits of electrical synapses?
synchronisation of neuronal groups
bi-directional
What is a vesicle?
bundle of membrane containing neurotransmitters
