STUDY neurotransmitter receptors

Nicotinic ACh receptor

example of inotropic NT receptor

-receptor for ACh

-channel for cations but mainly Na+ (sometimes K+, Calcium, chloride)

Nicotinic ACh receptor leads to what and why

leads to initial depolarization & EPSP because it introduces cations into cell

what channels do  metabotropic NT Receptors open

indirectly opens channels that are further along the post synaptic membrane 

how do metabotropic NT Receptors open channels

by activating signal transduction pathways, which involves the use of G protien coupled receptors 

-sequence of intracellular events 

What does G protien consist of 

3 subunits 

-alpha, betta, gamma 

G protien coupled receptors location

it is linked to the Metabotropic NT Receptors

example of Metabotropic NT Receptors

Adrenergic Norepinephrine Receptor

3 types of ionotropic glutamate receptors 

NMDA, AMPA, kainate receptors 

8 types of metabotropic glutamate receptors

mGluR1 to mGluR8

GABA_A receptors =

ionotropic receptors

GABA_B receptors

metabotropic receptors 

some NTs can be excitatory or inhibitory depending on what

the receptor they bind to an the location of the receptor 

when is ACh an excitatory NT

when it binds to nicotinic ACh

nicotinic ACh receptor location

skeletal muscle & ionotropic

when is ACh an inhibitory NT

when it binds to musscaranic ACh

musscaranic ACh receptor location and what kind of receptor

smooth muscle and metabatropic

when is GABA an inhibitory NT

in mature/adult brain 

when is GABA an excitatory NT

in developing brain (child)

why is GABA an excitatory NT in child brain

Chloride gradient is reveres in chuld’s brain

CI- high inside cell → Cl- leaves → cell positive → depolarization

what is Nitric Oxide

a gas produced by some nuerons 

how does Nitric Oxide diffuse

it diffuses ACROSS the presynaptic membrane → into a large area → then diffuses into target cell 

NO receptor and its location

Guanylyl cyclase

-present inside target cell

Gaunylyl Cyclase dual function

receptor and enzyme

Gaunylyl Cyclase as a receptor 

activates the production of cGMP as a second messenger 

cGMP

activates protien Kinase G  if PED-5 is inhibited (PKG)

activation of PKG leads to what 

→ relax smooth muscle cells → vasodilation

cGMP if PDE-5 is active 

leads to GMP production 

NO release leads to what mainly

vasodilation 

presence of PDE 5

breaks down cGMP into GMP which means no vasodilation

what happens to smooth muscles if cGMP breaks down

no smooth muscles relaxation, no vasodilation occurs

why would a phosphodiesterase 5 inhibitor cause vasodilation

no cGMP breakdown  leads to PKG which relaxes smooth muscles 

famous PDE 5 inhibitors

ED medicine

-erectile dysfunction medicine