Concept of Synapse

• Ramón y Cajal - anatomically demonstrated a narrow gap separating one neuron from another during the late 1800's
• late 1800s - when Ramón y Cajal anatomically demonstrated a narrow gap separating one neuron from another
• Charles Scott Sherrington - physiologically demonstrated that communication between one neuron and the next differs from communication along a single axon in 1906
• 1906 - when Charles Scott Sherrington physiologically demonstrated that communication between one neuron and the next differs from communication along a single axon
• Charles Scott Sherrington - He inferred a specialized gap between neurons
• Charles Scott Sherrington - introduced the term synapse
• Synapse - term introduced by Charles Scott Sherrington
• Reflex - is an automatic muscular responses to stimuli
• Reflex - a sensory neuron excites a second neuron, which in turn excites a motor neuron, which excites a muscle
• reflex arc - circuit from sensory neuron to muscle response
• Temporal Summation - summation over time
• Temporal Summation - light pinch of the dog’s foot did not evoke a reflex, but a few rapidly repeated pinches did.
• presynaptic neuron - the neuron that delivers transmission
• postsynaptic neuron - the neuron that receives
• action potential - produced when the combination exceeds the threshold of the postsynaptic neuron
• excitatory postsynaptic potential - is the long version of the abbreviation EPSP
• EPSP - A graded depolarization
• Decay - the effect of when EPSP to depolarization when it doesn't cause the cell to reach its threshold
• Spatial Summation - Summation over space
• Spatial Summation - Synaptic inputs from separate locations combine

  their effects on a neuron
• Neuron - synthesizes chemicals that serve as neurotransmitters.
• Neurotransmitters - are chemical messengers
• Tryptophan - an amino acid, a precursor to serotonin.
• Presynaptic Terminal - where most neurotransmitters are synthesized near point of release
• Vesicles - tiny nearly spherical packets
• Vesicles - where presynaptic terminal stores high concentrations of neurotransmitter.
• Monoamine Oxidase - breaks down these transmitters into inactive chemicals, thereby preventing the transmitters to accumulate to harmful levels
• Exocystosis - burst of release of neurotransmitter from the presynaptic neuron
• Ionotropic effect - refers to when a neurotransmitter attaches to receptors and immediately opens ion channels
• Transmitter-gated - are channels controlled by a neurotransmitter.
• Glutamate or GABA - what most ionotropic effects rely on
• guanosine triphosphate - energy storing molecule
• G-protein - increases the concentration of a second messenger
• Neuromodulators - they are often called Neuropeptides
• Neuromodulators - Release requires repeated stimulation
• Neurotransmitters are released by the axon; Neuropeptides are released by the dendrites and cell body
• Neuropeptides - often called neuromodulators
• Hallucinogenic Drugs or LSD- that is, drugs that distort perception
• LSD - chemically resembles serotonin
• Nicotine - compound found in tobacco