Synaptic connections ~100,000,000,000 neurons in human brain Each neuron contacts 1000 cells Foms~10,000 connections/cell How many synapses?
Synaptic connections • ~100,000,000,000 neurons in human brain • Each neuron contacts ~1000 cells • Forms ~10,000 connections/cell • How many synapses?
Neurotransmitter- communication via a chemical intermediary Chemical Synapses called a neurotransmitter Axon released from one Ca2 ca 2+ Action otentials Action otential neuron and influences Ca2+ Protein kinase activates a Ca2+ another (inactive) Calmodulin Protein kinase Synaptic (inactive) vesicles phosphorylates synapsin Synaptic cleft- a small Docking proteins ynaptic cle gap between the Q Fusion and eXOcytOSIS sending(presynaptic Neurotransmitter. released and the receiving Ca2+ (postsynaptic) site
•Neurotransmittercommunication via a chemical intermediary called a neurotransmitter, released from one neuron and influences another •Synaptic cleft- a small gap between the sending (presynaptic) and the receiving (postsynaptic) site Chemical Synapses
Synaptic vesicles. small spherical or oval organelles contain Chemical Synapses chemical transmitter used in transmission Action Axon Ca otentials Action otential Ca2+ Protein kinase activates a Ca2+ (inactive) Calmodulin Protein kinase Polarization Synaptic (inactive) vesicles phosphorylates communication occurs synapsin proteins in only one direction Synaptic cleft Docking Ca2 Fusion and from sending eXOcytOSIS Neurotransmitter. released presynaptic site, to Ca2+ receiving postsynaptic Site
•Synaptic vesiclessmall spherical or oval organelles contain chemical transmitter used in transmission •Polarizationcommunication occurs in only one direction, from sending presynaptic site, to receiving postsynaptic site Chemical Synapses
1. Synaptic Transmission model Precursor transport NT synthesis Storage Release Activation Termination - diffusion, degradation, uptake autoreceptors
• Precursor transport • NT synthesis • Storage • Release • Activation • Termination ~diffusion, degradation, uptake, autoreceptors 1. Synaptic Transmission Model
Presynaptic Postsynaptic Axon terminal Membrane Terminal Button Dendritic Spine
Presynaptic Axon Terminal Postsynaptic Membrane Terminal Button Dendritic Spine