PS263 Lecture Notes - Lecture 3: Gaba Receptor, Excitatory Synapse, Nucleus Accumbens
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Or: g-protein receptors activate downstream pathways, enzymes in postsynaptic soma cause depolarization. At terminal bulb (bouton), depolarization opens voltage-gated ca+ channels: ca+ enters cell, vesicles containing neurotransmitter fuse with membrane, neurotransmitter spills into synaptic cleft, attaches to the receptors on post-synaptic cell. Positive ions (na+, k+, ca+, excitatory) glutamate. Channel that allows in positive ions excitatory synapse (due to depolarization) Ipsp cell becomes more negative less likely to fire: as the neurotransmitter molecule detaches, the channel closes, channel opening allows ions into postsynaptic cell, directly depolarizes it. Ionotropic receptors work really quickly around 1 millisecond from binding to opening. Does(cid:374)"t sta(cid:455) ope(cid:374) for lo(cid:374)g neurotransmitter detaches after about 5 milliseconds. Not ion channels, but are still intermembrane proteins. They are g-protein coupled receptors: activated by binding of neurotransmitter, cause lots of downstream effects inside cell. Neurotransmitter attaches to protein, the conformation changes, and that protein (cid:862)does thi(cid:374)gs(cid:863) to other protei(cid:374)s i(cid:374)side the (cid:272)ell, (cid:272)reati(cid:374)g a (cid:272)hai(cid:374) of e(cid:448)e(cid:374)ts: ex.
