Neuroplasticity

I know that the number of synapses between neurons can change as we age but does the total number of neurons in the body ever change?
I'm thinking about doing an EPQ on neuroplasticity because it seems like an interesting topic, so i don't have much exposure to the subject yet.

Reply 1

thegodofgod

Original post by Ngaden76

Yes, as we age beyond about 40, we start to lose neurons (mostly in the brain); this is known as neurodegeneration. It can lead to neurodegenerative diseases such as Alzheimer disease (loss of cholinergic neurons) and Parkinson's disease (loss of dopaminergic neurons).

Reply 2

Kallisto

Entertainment Forum Helper

Original post by thegodofgod

Yes, as we age beyond about 40, we start to lose neurons (mostly in the brain); (...)

As far as I know it even starts after the birth. I have read that a baby at one or two has already lost millions of neurons. Is that right?

Reply 3

thegodofgod

Original post by Kallisto

As far as I know it even starts after the birth. I have read that a baby at one or two has already lost millions of neurons. Is that right?

Yes, that's right, but up until the age of about 40, the rate of neurogenesis is greater than the rate of neurodegeneration, after which they swap over.

Reply 4

Kallisto

Entertainment Forum Helper

Original post by thegodofgod

Yes, that's right, but up until the age of about 40, the rate of neurogenesis is greater than the rate of neurodegeneration, after which they swap over.

I see. And this is the reason why it leads to Alzheimer diseases in an advanced age? Is it right that alzheimer diseases can be obviated by using the brain to think and to learn something new?

Reply 5

ndnd_ndnd

number of neurons decrease in neurodegeneration diseases but does it ever increase (when we learn new stuffs etc) ??

Reply 6

Kallisto

Entertainment Forum Helper

Original post by Ngaden76

number of neurons decrease in neurodegeneration diseases but does it ever increase (when we learn new stuffs etc) ??

No, not really. The number of neurons is fixed from the beginning, id est before the birth. The number of neurons cannot be increased! after the birth, the number of neurons already decreases to restrict them to the 'body functions'. In short: the brain is using so many neurons as required, no more!

If we learn something new, the number of neurons will not increase, but if learning is effective and understandable, the neurons are creating a higher number of networks, called dendrites. The better the neurons are connected, the better (id est effective) the learning.

Reply 7

ndnd_ndnd

Original post by Kallisto

thank you, I'm going to do an EPQ on neuroplasticity and was confused about what it means when they say the shape of the brain changes.

Reply 8

cptschwm

We can produce more neurones through the process of adult hippocampal neurogenesis, which only occurs in a few areas of the brain. So the number of neurones is definitely not fixed. Learning/memory is not a case of increased neurones but more to do with synaptic plasticity which is a strengthening of the synaptic signal between neurones following increased glutamatergic signalling.

Original post by Kallisto

Reply 9

Kallisto

Entertainment Forum Helper

Original post by cptschwm

We can produce more neurones through the process of adult hippocampal neurogenesis, which only occurs in a few areas of the brain. So the number of neurones is definitely not fixed. (...)

But this does not apply for the whole brain, but for some areas only? so for the great part of the brain the number of neurons are fixed?!

Reply 10

cptschwm

I suppose so. Although it isn't really that simple as we don't entirely know the effects AHN have. It has been implicated in mood disorders such as depression, and also in memory.

Original post by Kallisto

But this does not apply for the whole brain, but for some areas only? so for the great part of the brain the number of neurons are fixed?!