NeurotransmitterHarliansyah,Ph.D

Chairman of Dept. Biochemistry FKUY1st Floor YARSI TOWER, Cempaka Putih 10510, JakartaPh. +6221-4244 574 ext 3107Email: ianshr2001@yahoo.com

OverviewThe human brain contains about 1012 neurons, and some neurons make 1000 connections

Dendrites, cell body, axonThe cell body contains the nucleus, and this is where almost all protein synthesis occursThe cell body also contains nearly all of the lysosomesProteins and other molecules are transported from the nucleus via axoplasmic transportAxons are long processes specialized for the conduction of action potentialsThe nervous system also contains glial cells that support and nourish the neurons (Schwann cells in the peripheral nervous system)Types of neurons: sensory neurons, interneurons, motor neurons

Anatomy of the NeuronArrows indicate the direction of conduction of the action potentialA motor neuron typically has a single axonThe axon of the sensory neuron branches after it leaves the cell body

Both branches are structurally and functionally axonsThe cell body is located in the dorsal root ganglion near the spinal cord

How Do We Study Neural Communication ?

Neurotransmitter Receptors

SynapseTerm Synapse: Site where the Axon terminal or Collateral makes functional contact with another cells.Two kinds of Synapses:

Chemical: Membranes of contiguous, cells are closely apposed Neurotransmitter signals from pre synaptic cell to post synaptic cell. Physically separated but coupled via specialized structures, slower than electrical synapses. Uses diffusible neurotransmitter molecule Can be modulated and Metabolic amplification.

Synapse. contdElectrical:

Cells are electrically coupled by the presence of connexins. Very fast Metabolically economical Can mediate inhibitory and retrograde signaling

Mechanism of Action Potential

AcetylcholineGrandfather of all neurotransmittersSites of action

Vertebrate neuromuscular junction: nicotinicPre-and post-ganglionic parasympathetic: nicotinic and muscarinic, respectivelyPre-ganglionic parasympathetic: nicotinicPresent in CNS (both Muscarinic and Nicotinic receptors)Inactivated by hydrolysis (the only classical neurotransmitter that is inactivated by metabolism)Pathology

Alzheimer (?)

Acetylcholine Metabolism ACh is inactivated by hydrolysis

Thanks for your attention