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PHAR1001- Pharm of the brain
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- 1Where are there more transmitters? in the CNS or PNS?In the CNS (brain and spinal cord). The brain receives sensory information from the outside world though peripheral sensory neurones, processes it, stores it and then produces responses.
- It is remarkable that the main outputs of the brain are the autonomic nervous system and motor activation-in humans the motor control of speech and expressions makes us the unique individuals we all are. - 2What are the features of transmitters?- they are always AGONISTS and
the direction of effect and the duration of action of the transmitters are determined by their receptors - 3What are the features of receptors?- produce fast actions (directly gating ion channels; msec onset and offset) or have
slow effects (indirect links to ion channels and enzymes via G proteins; secs to mins)
- subsequent intracellular changes initiate changes in activity of neurones that are more subtle than those produced by fast receptor events. - 4What does neural excitation involve? and inhibition?- depolarization of the membrane
- inhibition is produced by hyperpolarisation - 5What are the drugs that produce the most selective effects on CNS?- drugs acting on receptors
-but drugs acting to alter release or breakdown of transmitters can be very useful - 6What is GLUTAMATE?- the main excitatory transmitter in the CNS
-most neurones use glutame to transfer information from place to place in the brain - 7How many receptors does glutamate has?- AMPA and NMDA receptors (ionotropic) on POSTSYNAPTIC sites
- a fast presynaptic excitatory kainite receptors
-and a number of slow METABOTROPIC receptors (G-protein) - 8How are ,the fast synaptic excitations mediated by glutamate seen throughout the CNS, activated?They are activated though the AMPA receptor that directly opens Na channels.
- 9Whys is NMDA receptor of considerable interest?- it has been implicated in development of visual systems, epilepsy, pain transmission, memory and cell death
-2 agonists are needed and the channel is both ligand-and voltage-gated; all other known channels are either one or the other
- - 10,- glycine is requred for activation of the complex in addition to the glutamate (ligand-gaing)
-the channel is plugges by physiological levels of magnesium- this is removed by depolarization of the membrane (voltaged-gating) - 11—
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- Fichas sobre PHAR1001- Pharm of the brain , creado por Margaret-Estefani Conde Paredes el 03/03/2017.
- Creado por
- Margaret-Estefani Conde Paredes
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