Individual neurons communicate with multiple other neurons. This interaction inc
ID: 96429 • Letter: I
Question
Individual neurons communicate with multiple other neurons. This interaction includes receiving inputs from the numerous other neurons in the form of postsynaptic potentials We were introduced to two types of postsynaptic potentials; excitatory postsynaptic potentials (EPSPs) that function to make action potential generation more likely (usually through depolarization) and inhibitory postsynaptic potentials (IPSPs) that function to make action potential generation less likely (usually through hyperpolarization) Summation is the additive effect of multiple sub-threshold graded postsynaptic potentials that determines whether the membrane potential at the axon hillock reaches the threshold potential for generation of an action potential. There are two types of summation; spatial and temporal. Temporal summation refers to the situation where overlapping postsynaptic potentials occur close in time such that a subsequent postsynaptic potential occurs before the membrane has returned to resting potential from a previous postsynaptic potential. Spatial summation refers to the situation where multiple inputs converging on a single postsynaptic neuron overlap close to one another, often occurring simultaneously, and summate in space. In both cases, the resultant summation of the incoming impulses determines whether the activation threshold required for action potential generation is reached Here, using the information provided above, consider the conditions (A,B,C,D) presented in the figure below and briefly describe in your response whether situations of summation are occurring, and, f so, specity the type of summation Summarize in a few lines how the resultant effect of each condition impacts action potential generation and neural transmission. Your responses should not exceed one paragraph.Explanation / Answer
In condition A, the two stimuli arrived one after another from Ex1 with proper time gap (more than 10msec) and none of them are sufficient enough to provide a depolarisation. So, their effect is not summed and there go action potential generated. In condition be both the stimuli came together from Ex1 and thus their effects summed and that is good enough to provide action potential. In condition C, the two stimuli arrived one after another from Ex1 with proper time gap which unable to give rise any action potential but third time two stimuli came from Ex1 and Ex2 and thus their total effects able to give rise a action potential. In condition D, the first stimulus from Ex1 unable to give rise any action potential where as a inhibitory stimuli is good enough to rise hyperpolarisation where as in case of third time two stimuli one excitatory and another inhibitory arrive together thus causes a special summation which unable to give rise any action potential.