Having trouble with the video. Link here: http://archive.org/details/RobertSapolsky-BiologyAndHumanBehavior
Is learning about strengthening pre-existing synapses? That's the current thinking. By making the connection stronger, it becomes more likely that an action potential will be reached in the second neuron. Long term potentiation (LTP). The stronger the connection, the bigger the wave of excitation.
The brain can grow new neurons (in the hippocampus). Alzheimer's disease erodes the hippocampus. It's the area of the brain that causes synapses to be strengthened
The same thing can happen in the amygdala (PTSD, phobias), the spine (pain, diseases that are about pain).
Glutamate - neurotransmitter involved in LTP. Most exciting neuron known (generates a greater wave of excitation than the others). It has 2 receptors, fill both and you get a tidal wave of excitation. Non-linear; aha moments. Calcium ions pour in and open up the second, calcium gated receptor. The receptors undergo phosphorylation, which results in the receptors staying open for longer periods of time. So the post synaptic neuron listens better, has more receptors, is open longer and is more receptive to the messages.
There are neurotransmitters in the dendritic spine, retrograde neurotransmitters that go backwards. Nitric oxide is one and it's made of gas. Others are made of membrane. Utterly bizarre. Their role is to go back and hit the original neuron and trigger the release of more glutamate.
But too much glutamate and you have an excito-toxin. Too much firing can destroy the receiving neuron. This is part of what happens in a stroke or epileptic fit. In a stroke your brain is deprived of energy and cannot clear glutamate out of the synapse. So it fires and fires and you have glutamatergic toxicity. MSG can get into babies brains so it's banned from baby food these days. (He notes that he grew up in an era when it wasn't banned. And he went to Harvard and teaches at Stanford, so maybe it's not all bad...)
Aspertame, NutraSweet, when broken down it produces a neurotransmitter that's similar to glutamate.
LTP is helped by good nutrition/energy. Glucocorticoids (stress hormones) can also enhance LTP in the short term but mess it up over the long term. Alcohol also interferes with LTP.
And there are individual differences - glutamate levels, receptivity of neurons, shapes, phosphorylation. A gene manipulation experiment in mice produced some Secret of NIMH mice and some moronic ones by juicing up glutamate activity in one and knocking out the gene in another. But putting the morons in a highly stimulatory environment the effects were counteracted.
Is learning about strengthening pre-existing synapses? That's the current thinking. By making the connection stronger, it becomes more likely that an action potential will be reached in the second neuron. Long term potentiation (LTP). The stronger the connection, the bigger the wave of excitation.
The brain can grow new neurons (in the hippocampus). Alzheimer's disease erodes the hippocampus. It's the area of the brain that causes synapses to be strengthened
The same thing can happen in the amygdala (PTSD, phobias), the spine (pain, diseases that are about pain).
Glutamate - neurotransmitter involved in LTP. Most exciting neuron known (generates a greater wave of excitation than the others). It has 2 receptors, fill both and you get a tidal wave of excitation. Non-linear; aha moments. Calcium ions pour in and open up the second, calcium gated receptor. The receptors undergo phosphorylation, which results in the receptors staying open for longer periods of time. So the post synaptic neuron listens better, has more receptors, is open longer and is more receptive to the messages.
There are neurotransmitters in the dendritic spine, retrograde neurotransmitters that go backwards. Nitric oxide is one and it's made of gas. Others are made of membrane. Utterly bizarre. Their role is to go back and hit the original neuron and trigger the release of more glutamate.
But too much glutamate and you have an excito-toxin. Too much firing can destroy the receiving neuron. This is part of what happens in a stroke or epileptic fit. In a stroke your brain is deprived of energy and cannot clear glutamate out of the synapse. So it fires and fires and you have glutamatergic toxicity. MSG can get into babies brains so it's banned from baby food these days. (He notes that he grew up in an era when it wasn't banned. And he went to Harvard and teaches at Stanford, so maybe it's not all bad...)
Aspertame, NutraSweet, when broken down it produces a neurotransmitter that's similar to glutamate.
LTP is helped by good nutrition/energy. Glucocorticoids (stress hormones) can also enhance LTP in the short term but mess it up over the long term. Alcohol also interferes with LTP.
And there are individual differences - glutamate levels, receptivity of neurons, shapes, phosphorylation. A gene manipulation experiment in mice produced some Secret of NIMH mice and some moronic ones by juicing up glutamate activity in one and knocking out the gene in another. But putting the morons in a highly stimulatory environment the effects were counteracted.