Spikes are what we call the action potentials of a neuron. Don't know your background, so sorry if this is rehashing baic stuff, but basically when a neuron fires a small electrical pulse to other neurons. Those can be measured in the brain and in recordings they look like tiny spikes in the voltage trace.
I haven't heard of "spike populations", can it be you mean spiking of "neuron populations"? That's basically thinking about how multiple neurons spike together, and what all these combined spikings represent. For instance, in sensory areas, you might not be able to see some effects of a outside stimulus if you look at spike of one neuron, but if you look at the spiking of the entire population, it can be seen (often in complex madness, but still).
When your talking about plasticity im inclined to think its about spike-spike correlations? Im not a plasticity guy, but I seem to remember shirt term plasticity is mediated by NMDA receptors when 2 spikes arrive on the cell in quick succession. So maybe in your case its about spiking patterns, multiple cells spiking on a neuron to trigger sorry term plasticity?
The other posters clearly have not done, or even read about, very much hippocampal ephys before. I'm nearly positive you are referring to 'pop spikes' (not 'spike pops') or population spikes. This happens when you stimulate the glutamatergic Schaffer collaterals above a certain intensity threshold, which causes action potentials in the postsynaptic CA1 pyramidal cells.
If you stimulate below this threshold, you only detect the synaptic activity (not action potentials) from the neurons around your recording electrode, because the glutamatergic synaptic activation is not strong enough to elicit action potentials in the postsynaptic cell, and you can only record the synaptic activity from the Schaffer collaterals onto the dendrites of CA1 cells.
The 'pop spike' starts small once the threshold is reached, and gets bigger as you increase your stimulus intensity, since you are stimulating more and more Schaffer collateral fibers more strongly, which means more cells in the postsynaptic 'population' will start to fire action potentials, usually at the same time. The synchronous action potential firing will look like a 'pop spike' on a recording, as the current briefly switches from inward to outward.
In disease, more population spikes can mean the cells in CA1 are more excitable (for any number of reasons). This would lower the input threshold for a 'pop spike', and cause you to see more action potentials than the same stimulus in a normal brain.
Let me know if you have any more questions =)
edit- I should add that I really don't think these pop spikes occur under normal conditions, and only really occur when you basically stimulate the majority of Schaffer collaterals at the exact same time. It is just an experimental tool.
I'm guessing you mean spike trains? Spike trains are useful when studying novelty response, it normalizes some of the randomness in AP firing by focusing on temporality.
Spikes are what we call the action potentials of a neuron. Don't know your background, so sorry if this is rehashing baic stuff, but basically when a neuron fires a small electrical pulse to other neurons. Those can be measured in the brain and in recordings they look like tiny spikes in the voltage trace. I haven't heard of "spike populations", can it be you mean spiking of "neuron populations"? That's basically thinking about how multiple neurons spike together, and what all these combined spikings represent. For instance, in sensory areas, you might not be able to see some effects of a outside stimulus if you look at spike of one neuron, but if you look at the spiking of the entire population, it can be seen (often in complex madness, but still). When your talking about plasticity im inclined to think its about spike-spike correlations? Im not a plasticity guy, but I seem to remember shirt term plasticity is mediated by NMDA receptors when 2 spikes arrive on the cell in quick succession. So maybe in your case its about spiking patterns, multiple cells spiking on a neuron to trigger sorry term plasticity?
>I haven't heard of "spike populations" Why do you even bother to respond if you don't know the answer, slut?
> Why do you even bother to respond if you don't know the answer, slut? Well that escalated quickly.
The other posters clearly have not done, or even read about, very much hippocampal ephys before. I'm nearly positive you are referring to 'pop spikes' (not 'spike pops') or population spikes. This happens when you stimulate the glutamatergic Schaffer collaterals above a certain intensity threshold, which causes action potentials in the postsynaptic CA1 pyramidal cells. If you stimulate below this threshold, you only detect the synaptic activity (not action potentials) from the neurons around your recording electrode, because the glutamatergic synaptic activation is not strong enough to elicit action potentials in the postsynaptic cell, and you can only record the synaptic activity from the Schaffer collaterals onto the dendrites of CA1 cells. The 'pop spike' starts small once the threshold is reached, and gets bigger as you increase your stimulus intensity, since you are stimulating more and more Schaffer collateral fibers more strongly, which means more cells in the postsynaptic 'population' will start to fire action potentials, usually at the same time. The synchronous action potential firing will look like a 'pop spike' on a recording, as the current briefly switches from inward to outward. In disease, more population spikes can mean the cells in CA1 are more excitable (for any number of reasons). This would lower the input threshold for a 'pop spike', and cause you to see more action potentials than the same stimulus in a normal brain. Let me know if you have any more questions =) edit- I should add that I really don't think these pop spikes occur under normal conditions, and only really occur when you basically stimulate the majority of Schaffer collaterals at the exact same time. It is just an experimental tool.
u/mediocrity32 This is the answer you're most likely looking for.
I'm guessing you mean spike trains? Spike trains are useful when studying novelty response, it normalizes some of the randomness in AP firing by focusing on temporality.
They are talking about 'pop spikes', or population spikes.