Lecture 3 - Neural Communication

Lecture 3 - Neural Communication - Neural Neural...

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Unformatted text preview: Neural Neural Communication Basic Terminology – Neuronal Parts Basic Terminology – Neuronal Parts Neuron – basic building block of the nervous Neuron system system Dendrite – part of neuron that receives Dendrite messages from other cells and passes the messages to the cell body messages Cell Body – control center of neuron, contains Cell nucleus nucleus Axon – sends messages to other neurons, Axon glands, muscles, etc glands, Cont. Cont. Myelin Sheath – fatty tissue covering some Myelin axons, speeds conduction of neural impulse axons, Synapse – Junction between axon of one Synapse neuron and dendrite of another neuron Receptor – protein that binds Receptor neurotransmitters, hormones, or drugs neurotransmitters, Basic Terminology – Neural Basic Terminology – Neural Communication Action potential – brief electrical charge that Action travels down an axon. Caused by positively charged ions moving in and out of channels on the axon’s membrane. the Threshold – the level of stimulation required Threshold to trigger an action potential. Threshold is reached through depolarization. reached Cont. Cont. Depolarization – When the inside of an axon Depolarization becomes more positive through an inward flow of ions. of Hyperpolarization – Return of the inside of the Hyperpolarization axon to a more negative charge. axon Cont. Cont. All-or-none – Action potentials can’t be All-or-none partial, they either happen or they don’t. partial, Refractory period – the period in which a new Refractory action potential can’t occur Neurotransmitters Neurotransmitters - - Chemical messengers that traverse the Chemical synaptic gaps between neurons and bind to receptors. receptors. Dopamine – movement, learning, attention, Dopamine emotion, reward (linked with schizophrenia, Parkinson’s) Parkinson’s) Cont. Cont. - - - - Serotonin – mood, hunger, sleep, arousal Serotonin (linked with depression) (linked Norepinephrine – alertness and arousal (linked Norepinephrine with depression) with Endorphins – natural opiate-like transmitters Endorphins linked to pain control and pleasure linked 50-60 types of known neurotransmitters Sequence of Events Sequence of Events 1. 2. 3. 4. Dendrite receives messages in the form of Dendrite neurotransmitters. neurotransmitters. Through temporal and spatial summation, Through message is passed to cell body. message Depolarization of cell body begins. If depolarization is sufficient to reach If threshold, action potential occurs. threshold, Cont. Cont. 1. 2. 3. 4. Action potential travels down axon. At the synapse, action potential is converted At to neurotransmitter which is released into synaptic cleft. synaptic NT binds to receptors on dendrites of next NT neuron (Process starts over in new neuron) . neuron Hyperpolarization occurs in original neuron Hyperpolarization and refractory period is entered. and ...
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