Chapter 3 : Biological basis of behaviour (3) Flashcards
How is normal development characterized?
Normal development is characterized more by the elimination of old synapses appears than the creation of new synapses.
The nervous system normally forms more
synapses than needed and then gradually eliminates the less-active synapses
What is synaptic pruning? What is its significance?
This elimination of old or less-active synapses is called synaptic pruning.
It appears to be a key process in the formation and strengthening of the neural networks that are crucial to communication in the nervous system
Define long term potentiation.
Long-term potentiation refers to a longlasting increase in neural excitability in synapses along a specific neural pathway
What are the 4 common properties neurotransmittors share?
- They are synthesized in the neuron.
- They are stored in the synaptic terminals.
- They are released when the neuron has an action potential.
- They are deactivated or removed from the synapse when they have completed their task.
What are the two effects a neurotransmitter has when it is released into the synapse?
They either increase the chance of the postsynaptic cell firing (i.e., they produce EP potential) or they decrease the chance of the postsynaptic cell firing (i.e., they produce IP potentials).
What is an agonist?
An agonist is a chemical that mimics the action of a neurotransmitter.
What is an antagonist?
An antagonist is a chemical that opposes the action of a neurotransmitter.
What is the only transmitter between motor neurons and voluntary muscles?
Acetylcholine.
What are the uses of acetylcholine?
Every move you make—requires that
ACh is released to your muscles by motor neurons .
ACh also appears to contribute to attention, arousal, and memory.
What are some Ach agonists?
Ach receptors are stimulated by Nicotine
What disease can inadequate supply of acetylcholine lead to?
An inadequate supply of ACh in certain areas of the brain is associated with the memory losses seen in Alzheimer’s disease
What is an example of an acteylcholine antagonist?
Curare.
What neurotransmitters belong to monamine?
Dopamine, Norepinephrenine and serotonin.
What is dopamine used for?
- Contributes to control of voluntary movement, learning and attention
- Plays a role in pleasure and rewards. Dopamine circuits in the medial forebrain are charcaterized as ‘‘reward pathway’’.
When is dopamine released?
More dopamine is released when you engage in rewarding activities such as eating when you are hungry, drinking when you are thirsty etc.
