synapse & neurotransmitters
Nerve impulses pass between neurons at synapses.
Pre-synaptic neuron --> Post-synaptic neuron (dendrite or cell body)
Neurotransmitters are released at the end of axons by a nerve impulse, creating a depolarization of the dendrites of the postsynaptic neuron.
Pre-synaptic neuron --> Post-synaptic neuron (dendrite or cell body)
Neurotransmitters are released at the end of axons by a nerve impulse, creating a depolarization of the dendrites of the postsynaptic neuron.
- The arriving action potential depolarizes the presynaptic membrane and Ca+ channels open.
- Ca+ ions enter the presynaptic axon terminal, which activates the neurotransmitters to fuse at the end plates and be released into the synaptic cleft.
- The neurotransmitters released will either have an excitatory or inhibitory effect on the postsynaptic membrane
Excitatory Effect
Neurotransmitters will bind to receptor sites of the postsynaptic membrane, causing Sodium to move into the cell, causing depolarization.
Inhibitory Effect
Neurotransmitters will bind to receptor sites of the presynaptic membrane, causing negative ions to move into the cell, causing hyperpolarization.
Neurotransmitters will bind to receptor sites of the postsynaptic membrane, causing Sodium to move into the cell, causing depolarization.
Inhibitory Effect
Neurotransmitters will bind to receptor sites of the presynaptic membrane, causing negative ions to move into the cell, causing hyperpolarization.
Let's take a look at a form of neurotransmitters, the painkillers.
Resources:
DiGiuseppe, Maurice et al. (2003). Nelson Biology 12. Nelson Canada ELHI (1 Edition). Toronto, Ontario: Thomson Canada Limited
DiGiuseppe, Maurice et al. (2003). Nelson Biology 12. Nelson Canada ELHI (1 Edition). Toronto, Ontario: Thomson Canada Limited