Excitatory Postsynaptic Potentials and Action Potentials - Assignment Example

By inhibiting the reticular activating system in the brain stem, the preoptic nucleus makes the cortex sleep. Therefore, consciousness depends on the normal workings of the brain.

2. Describe three differences between EPSPs and action potentials.

Excitatory postsynaptic potentials Action potentials
EPSPs occur on the cell bodies (of the neuron) as well as the dendrites. Excitatory postsynaptic potentials results from the activation of ions on the postsynaptic channel. The channel opens, giving way for the ions to move across the membrane, which causes depolarization Contrary, action potential responses are initiated in the axon hillock and are not degraded as they are propagated down the axon.

In this case, due to the degradation of the activation, the amplitude decreases as the change in voltage moves far from the post-synaptic channel. The action potential does not undergo degradation during transfer; hence, the amplitude is the same.
Many EPSPs that simultaneously arrive at axon hillocks are responsible for the generation of a single action potential. An action potential is transferred through neurotransmitters, to a postsynaptic neuron

3. What organ is lateral to the amygdala, posterior to the eye, and has two windows?
Inner Ear
4. How may a drug’s action at a synapse explain its effects on behavior?
A drug interferes with normal neurotransmission. Therefore, a drug alters how neurons communicate since it dopamine mediation of neurons is interfered with. A drug can affect the synapse by increasing the neurotransmitter in the synaptic space. This may increase the action potential, hence amplifying behavior such as the feeling of pleasure. Sometimes, drugs may interfere directly with the postsynaptic receptors.

While some drugs block, others activate the receptors. In this case, a drug can affect the brain by inhibiting the neuromodulator from binding with the required receptor, therefore blocking the part responsible for sleep from causing sedation. Drugs such as LSD blocks the dopamine transporter between serotonin receptors; thus resulting in a change in moods and eating. Finally, a drug can interfere with the removal of neurotransmitters contained in the synapse. Such a drug blocks the dopamine transporter, which may result in euphoria due to the accumulation of dopamine.

5. How would you describe the difference between what the retina does and what the striate cortex does?
The retina acts as the interface to the brain by transforming light into electrical impulses. On the other hand, the striate cortex receives translated information and converts it to actual perception of the environment.
6. Describe how the auditory system encodes the frequency of a sound.
To encode sound, the auditory system decomposes the amplitude signal that arrives at the ear into several bands of the frequency with each frequency being approximately an algorithmic function of the length from the stapes. Read More