lecture 3 - claudia racca Flashcards
where are neurotransmitters found
at chemical synapses
what do NTs do
act as chemical signals
NTs released from vesicle by exocytosis, it interacts with specific molecules on the post synaptic side. what does this activate
signalling cascade
in inhibitory synapses what NT is released
GABA
in inhibitory synapses what receptor is on the post synaptic side
GABA receptors
excitatory synapses release what NTs
glutamate
what are the receptors on the post synaptic side of excitatory synapse
AMPA and NMDA receptors
what is post synaptic density
a huge protein complex attached to post synaptic membrane, its only found in excitatory synapses
excitatory synapses synapse on the…
dendritic spines
inhibitory synapses synapse on the
dendritic trunk or the soma
criteria that define a NT
- the substance must be present within presynaptic neuron
- the substance must be released in response to presynaptic depolarisation, and the release must be Ca dependant
- specific receptors for the substance must be present on the postsynaptic neuron
what are the 3 major types on NTs
- low molecular weight transmitters
- peptides
- gases
example of low molecular weight transmitters
ACh, amino acids, purines
example of peptide NTs
substance P, opioids, somatostatin, vasopressin
example of gas NTs
NO, CO
example of amino acids NTs
glutamate, GABA, aspartate, glycine
GABA and glycine are inhibitory, which is the major inhibitor in the brain and which in the spinal cord
GABA - brain
glycine - spinal cord
which is the major excitatory NTs
glutamate
life of a NT
- synthesis
- packaging into vesicles
- release from vesicles
- activation of specific receptors
- removal from the synaptic cleft
the small molecule transmitters will be synthesised and packaged where
in the terminal
where are peptide neurotransmitters formed
in the cell body
what vesicles do low molecular weight neurotransmitters go into
small clear core vesicles
what vesicles do bioamines and neuropeptides go into
dense core vesicles
what are the two types of receptors on the post synaptic membrane
ionotropic and metabotropic receptors
how do ionotropic receptors work
ion channel, transmembrane protein that has a pore in the middle. the pore will open once it binds to NT allowing movement of ions in
how do metabotropic receptors work
transmembrane proteins
they bind the NT
the G protein will then be activated and the subunits or intracellular messengers modulate ion channels allowing ions to flow across the membrane
mechanisms for removal of NT from the synaptic cleft
- diffusion in combination with reuptake
- degradation by enzymes
