idk the name yet, but rest of flashcards
(19 cards)
excitatory vs inhibitory neurotransmitters
excitatory - increase the chance that the receiving postsynaptic neuron will fire an action potential by depolarizing the postsynaptic membrane
Inhibitory - makes the postsynaptic neuron less likely to fire an action potential through hyperpolarizating the membrane (moving it further away from the threshold)
acetylcholine
- neurotransmitter for muscle contractions
- excitatory and inhibitory effects
glutamate
- excitatory neurotransmitter in the brain and CNS
- essential for learning, memory, and the development of the brain
Norepinephrine
- involved in the body’s flight or fight response
- excitatory
GABA
- main inhibitory neurotransmitter in the brain and CNS
- prevents over excitation of neurons
dopamine
- inhibitory or excitatory
- plays a vital role in movements, motivation, reward, mood, and attention
seratonin
- inhibitory or excitatory
- affects attention and emotional state
Ion channels vs signaling cascades
ion channels
- open through inotropic receptors (special proteins that act as receptors and ion channels)
- very fast
signaling cascades
- bind to metabotropic receptors and tell them to open the ion channels
- slower, but long-lasting
how can synaptic signals be turned off
- recycling the neurotransmitter in the presynaptic neuron by proteins
- enzymatic breakdown in the synaptic cleft
- diffusion of the neurotransmitter into the surrounding fluid
Why is turning off synaptic signals important
- prevents overstimulation
- allows new signals to happen - allows neurons to reset
- keeps signals specific - ensures timing and communication
- keeps excitatory and inhibitory signals in control
what is an Excitatory Postsynaptic Potential (EPSP)
a graded depolarization caused by the arrival of a neurotransmitter at the postsynaptic membrane
what is an Inhibitory Postsynaptic Potential (IPSP)
a graded hyperpolarization of the postsynaptic membrane
How does the cell decide how to response to many signals?
The neuron acts like a calculator — it adds up all the “yes” (EPSP) and “no” (IPSP) votes. If the total is strong enough (us, it sends the signal (fires an action potential)
How can a cell increase EPSPs
1) Temporal Summation
A single synapse fires repeatedly in a short time, causing EPSPs to build up before the membrane resets
This increases the total depolarization.
2) Spatial Summation
Multiple excitatory synapses on different parts of the neuron fire at the same time.
Their combined EPSPs add together, making a larger effect.
How can facilitating and inhibiting neurons influence neural signaling
1) Facilitating neurons enhances neural signaling by increasing EPSPs which increases neurotransmitter release which makes postsynaptic neurons more responsive
2) Inhibiting neurons suppress neural signaling by releasing IPSPs which hyperpolarizes the membrane which makes it harder to reach the threshold
What is neural coding and how does it work?
What
- how neurons encode sensory input, thoughts, and commands into electrical signals
How
- neurons use action potentials to transmit information
define the following neural circuits
Diverging:
A circuit for spreading stimulation to multiple neurons or neuronal pools in the CNS
Converging:
a circuit for providing input to a single neuron from multiple sources
Reverberating:
a positive feedback circuit
Parallel after-discharge:
a circuit in which neurons or pools process the same information simultaneously
What is neuroplasticity?
the brains ability to change and adapt in response to the structural and functional changes in neurons and their synapses overtime.
What changes about neurons when you learn?
- synaptic strength
- new synapses
- dendritic changes
- pruning
- molecular changes
