Flashcards in lecture 29 - Synaptic transmission Deck (40)
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1
glutamate transporter
removes glutamate to presynaptic terminals and astrocytes. Other transporters take it to be stored in synaptic vesicles
2
what are the 2 classes of neurotransmitters?
- small molecule neurotransmitters ('classical')
- neuropeptides ('neuromodulators')
3
substance P and endorphins
neuropeptides
4
synapse found in retina
electrical synapse
5
what does the increase of permeability to Cl-, due to IPSPs, cause ?
decreased cell membrane resistance. They make the current induced by EPSPs less efficient in bringing postsynaptic membrane to threshold.
6
metabotropic
indirectly gated glutamate receptors
7
how are most amino acids inactivated?
re-uptake
8
factors affecting synaptic action:
(a) type of neurotransmitter/neuroregulator
(b) type of neurotansmitter receptor expressed in post-synaptic membrane/ multiple receptor subtypes
(c) number of neurotransmitter receptors in the postsynaptic membrane - synaptic plasticity
9
Direct gating of ion channels (characteristics and features)
- transmitter binds directly to the ion channel complex and the pore opens
- very fast onset
- short-lived
10
neuromuscular junction =
chemical synaptic transmission between the axon terminals of motoneurons and the end-plates of muscle fibres
11
features of classical, small molecule neurotransmitters
fast action, acting directly
12
how small are the postsynaptic potentials?
around 0.1mV
13
AMPA, Kainate
directly gated glutamate receptors
14
too much glutamate release (or insufficient re-uptake) will lead to...
excitotoxicity: too much glutamate leads to excessive depolarisation of neurons. The long-term opening of NMDA receptors leads to excessive Ca2+ entering = damage to neurons
15
EPSPs and IPSPs work together TRUE/FALSE?
FALSE they work independently
16
axodentritic synapse
where the axon of one neuron communicates with the dentrite of another via chemical synapses
17
indirect gating of ion channels (characteristics and features)
- transmitter binds to G-protein coupled receptor or metabotropic receptors
-activates biochemical pathway, eventually opening pore
- slower onset
- longer-lasting
18
where would you find Pyramidal cells and what do they look like?
cerebral cortex of the brain. Pyramid shape
19
NPY
a neuropeptide
20
2 forms of synapses
1. chemical synapse
2. electrical synapse
21
IPSPs + EPSPs
cancel out
22
spatial summation
synapse activation occurs at the same time at many different synapses and the EPSPs add together
23
small molecule neurotransmitters include:
- Amino acids (glutamate, GABA, glycine)
- Acetylcholine (ACh)
- Amines (serotonin, dopamine, noradrenaline)
- others include ATP and Nitric oxide
24
inhibitory synapses cause a ________ of the post-synaptic membrane. The neurotransmitters involved are mainly ______ and ________ . Their ionic mechanism is the opening of the ion channels for __ and __ .
inhibitory synapses cause a _hyperpolarisation_ of the post-synaptic membrane. The neurotransmitters involved are mainly _GABA_ and _glycine_ . Their ionic mechanism is the opening of the ion channels for _K+_ and _Cl-_ .
25
through which type of cell junction are electrical synapses transmitted?
gap junction
26
where would you find Purkinje cells?
in the cerebellum
27
what are the two main chemical synapses in the CNS?
1. excitatory synapses (EPSPs)
2. inhibitory synapses (IPSPs)
28
excitatory synapses cause a ________ of the post-synaptic membrane. The neurotransmitters involved are mainly ________ _____ and ________ . Their ionic mechanism is the transient opening of the ion channels for __ and __ and sometimes __.
excitatory synapses cause a _depolarisation_ of the post-synaptic membrane. The neurotransmitters involved are mainly _glutamic_ _acid_(glutamate)_ and _Acetylcholine_(ACH)_ . Their ionic mechanism is the transient opening of the ion channels for _K+_ and _Na+_ and sometimes _Ca2+_.
29
features of neuropeptides
- Large molecules
- indirectly act on postsynatptic membrane
- slow and more dififfuse action
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