Neuro

Question 1

Define the characteristics of a neurotransmitter

Answer 1

-Synthesized within neurons
-Released into the synaptic cleft
-Binds to specific receptors
-Initiates a response in the target neuron
-Terminated through reuptake, enzymatic degradation, or diffusion
-Mediates various physiological and behavioral effects.

Question 2

What is the correct temporal sequence of events in chemical neurotransmission, beginning with the arrival of a wave of depolarization at the presynaptic membrane and ending with a graded potential generated at the postsynaptic membrane

Answer 2

1. Arrival of depolarisation
2. Calcium influx
3. Neurotransmitter release
4. Diffusion of neurotransmitter
5. Receptor activation
6. Graded potential generation

Question 3

Contrast the generation and conduction of graded synaptic potentials with that of action potentials

Answer 3

graded synaptic potentials are generated in the dendrites and soma of a neuron, influenced by synaptic inputs, and are passive, localized, and decremental. In contrast, action potentials are generated at the axon hillock, are actively propagated along the axon without decrement, and enable long-range communication within the neuron

Question 4

What is the ionic basis for excitatory post-synaptic potentials

Answer 4

Excitatory post-synaptic potentials (EPSPs) result from the influx of positively charged ions, such as sodium (Na+) or calcium (Ca2+), into the post-synaptic neuron. They depolarize the membrane and make the neuron more likely to generate an action potential, thereby enhancing synaptic transmission.

Question 5

What is the ionic basis for inhibitory post-synaptic potentials

Answer 5

Inhibitory post-synaptic potentials (IPSPs) occur when negatively charged ions, like chloride (Cl-) or positively charged ions like potassium (K+), flow into or out of the post-synaptic neuron, respectively. IPSPs hyperpolarize the membrane, making it more difficult for the neuron to reach the threshold for generating an action potential. This inhibition reduces synaptic transmission.

Question 6

What is Postsynaptic inhibition

Answer 6

Postsynaptic inhibition refers to the suppression of neuronal activity at the postsynaptic membrane, typically achieved through hyperpolarization or inhibitory neurotransmitter binding

Question 7

What is Presynaptic inhibition

Answer 7

Presynaptic inhibition refers to the inhibition of neurotransmitter release from the presynaptic terminal, resulting in decreased synaptic transmission onto the postsynaptic neuron.

Question 8

What is the short-term synaptic plasticity, duration and mechansim

Answer 8

Duration: The effects of short-term synaptic plasticity are temporary and typically last from milliseconds to seconds.
Mechanisms: Short-term plasticity is mainly driven by changes in presynaptic neurotransmitter release or postsynaptic receptor properties.

Question 9

What is the long-term synaptic plasticity, duration and mechansim

Answer 9

Duration: The effects of long-term synaptic plasticity can last from minutes to hours, days, or even longer.
Mechanisms: Long-term plasticity is often associated with structural changes in the synapse, such as changes in synaptic connections or alterations in the expression and function of specific proteins. It may involve processes like long-term potentiation (LTP), which strengthens synaptic connections, or long-term depression (LTD), which weakens synaptic connections