Dot Point 2 Flashcards
How are messages sent and received through the nervous system?
Messages are sent and received via neurochemicals, which are chemical substances that travel between neurons.
The two types of neurochemicals are neurotransmitters, which transmit signals between two neurons with immediate excitatory or inhibitory effects,
and neuromodulators, which influence neurotransmitter activity over a larger amount of nerurons
What are the two types of neurochemicals?
Neurotransmitters – affect one or two post-synaptic neurons, allowing for rapid communication.
Neuromodulators – affect multiple post-synaptic neurons by being released into multiple neural synapses, influencing neural activity on a larger scale.
What are neurotransmitters and how do they work?
Neurotransmitters are chemical substances that allow quick communication between two neurons across the neural synapse. They are often compared to a text message because of their rapid effect.
What are the two effects of neurotransmitters?
Excitatory effect – Activates post-synaptic neurons, making them more likely to fire.
Inhibitory effect – Prevents or blocks post-synaptic neurons from firing.
What is the primary excitatory neurotransmitter in the CNS, and what does it do?
Glutamate is the primary excitatory neurotransmitter. It is responsible for enhancing neural transmission and playing a key role in learning, memory, and synaptic plasticity.
What is the primary inhibitory neurotransmitter in the CNS, and what does it do?
Gamma-amino butyric acid (GABA) is the primary inhibitory neurotransmitter. It makes post-synaptic neurons less likely to fire, preventing excessive neural activity.
What happens if there is a deficiency of GABA?
A lack of GABA can lead to uncontrolled neural activity, potentially causing seizures (like in epilepsy) and anxiety disorders.
What are neuromodulators, and how do they work?
Neuromodulators are chemical substances that are released into multiple synapses, influencing neural activity on a larger and longer-lasting scale than neurotransmitters.
How do neuromodulators bind to post-synaptic neurons?
Each neuromodulator has a distinct chemical shape and binds to receptor sites that match it through the lock-and-key process.
What is dopamine, and what are its functions?
dopamine is a neurotransmitter that plays a crucial role in movement, motivation, and pleasure.
Dopamine can be both inhibitory and excitatory
Pleasure and reward – Dopamine is involved in the brain’s reward system, reinforcing behaviors that bring pleasure
Motivation and learning – It plays a role in reinforcing positive behaviors and is important for goal-directed behavior.
Can dopamine be excitatory or inhibitory?
Yes, dopamine’s effect depends on the type of receptor site in the brain.
What is the dopamine reward pathway, and how does it relate to addiction?
When exposed to rewarding stimuli, dopamine is released in an excitatory format, creating feelings of pleasure. Addictive behaviours (e.g., gambling) activate this pathway, reinforcing the behaviour and potentially leading to addiction.
What is serotonin, and what are its functions?
Serotonin is a neuromodulator that has an inhibitory effect and is responsible for:
Mood regulation and stabilization
Appetite and digestion
Arousal
How does serotonin affect digestion?
Approximately 90% of serotonin is found in the gut-brain axis, where it regulates bowel movements and reduces appetite
