The Six Layers of the Cerebral Cortex | Neuroscience 101

The mammalian neocortex exists of 6 layers, here we discuss them.
The cerebral cortex cosists of six layers:
First, the molecular layer which has very little neurons, and consists of glial cells, dendrites and axons.
Second, the external granular layer with small granule cells (pyramidal neurons).
Third, the external pyramidal layer with medium-sized pyramidal neurons. Together layer 2 and 3 are receive interhemispheric input.
Fourth, the internal granular layer, which is the layer that receives sensory input via the thalamus
Fifth, the internal pyramidal layer, which is the main output layer that has outgoing axons to other brain regions and the corticospinal tract. This layer has large pyramidal neurons (Betz cells).
Sixth, the multiform layer, which has a variety of neurons and reciprocal connections to the cortex.
References:
Azim, E., & Seki, K. (2019). Gain control in the sensorimotor system. Current opinion in physiology, 8, 177-187. doi.org/10.101...
Helmstaedter, M., Staiger, J. F., Sakmann, B., & Feldmeyer, D. (2008). Efficient recruitment of layer 2/3 interneurons by layer 4 input in single columns of rat somatosensory cortex. The Journal of neuroscience : the official journal of the Society for Neuroscience, 28(33), 8273-8284. doi.org/10.152...
Olsen, S. R., Bortone, D. S., Adesnik, H., & Scanziani, M. (2012). Gain control by layer six in cortical circuits of vision. Nature, 483(7387), 47-52. doi.org/10.103...
Quiquempoix, M., Fayad, S. L., Boutourlinsky, K., Leresche, N., Lambert, R. C., & Bessaih, T. (2018). Layer 2/3 Pyramidal Neurons Control the Gain of Cortical Output. Cell reports, 24(11), 2799-2807.e4. doi.org/10.101...
Scala, F., Kobak, D., Shan, S. et al. Layer 4 of mouse neocortex differs in cell types and circuit organization between sensory areas. Nat Commun 10, 4174 (2019). doi.org/10.103...
Schuman, B., Dellal, S., Prönneke, A., Machold, R., & Rudy, B. (2021). Neocortical Layer 1: An Elegant Solution to Top-Down and Bottom-Up Integration. Annual review of neuroscience, 44, 221-252. doi.org/10.114...
Thomson A. M. (2010). Neocortical layer 6, a review. Frontiers in neuroanatomy, 4, 13. doi.org/10.338...
Wagstyl, K., Larocque, S., Cucurull, G., Lepage, C., Cohen, J. P., Bludau, S., Palomero-Gallagher, N., Lewis, L. B., Funck, T., Spitzer, H., Dickscheid, T., Fletcher, P. C., Romero, A., Zilles, K., Amunts, K., Bengio, Y., & Evans, A. C. (2020). BigBrain 3D atlas of cortical layers: Cortical and laminar thickness gradients diverge in sensory and motor cortices. PLoS biology, 18(4), e3000678. doi.org/10.137...
Narrated and produced by: Miles Wischnewski
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[@literallyagalaxy7789]

if i was forced at gunpoint by a raging maniac to choose one of my layers to be removed which one should i choose to minimize the damages to my brain

[@real.psyched]

That is an extremely tough question. Obviously losing any of them would have severe consequences. I can only speculate, but I would pick layer 2 OR 3 (not both). Since layer 2 and 3 are functionally similar, I believe that any loss in function might be taken over by the other to some extent. And if I had to pick out of those, probably layer 2, since it is generally smaller than layer 3.
Certainly NOT layer 4 or 5. Layer 1 seems tempting, but all dendrites of the other layers are there, so that would have sever consequences too. Layer 6 is probably the most mysterious, but with so many connections to the thalamus, I think that is dangerous too.
So, at gunpoint, I pick layer 2

[@literallyagalaxy7789]

@@real.psyched Thank you very much for answering my hypothetical question which is of course is only in the realm of fantasy as I am not a hostage to any mad neurosurgeon nor I am being forced to type this message by one

[@BooleanDisorder]

​@@real.psychedthank you. I was just in this scenario and hgd hhj hgggfcggv ffff! 😂😂 hhffhhn? Tggg😢 ffff🎉

[@shaanramnah2153]

This is honestly a really good and interesting question

[@mankiddyman]

THANK YOU

[@Neuronalchannel]

Thanks!

[@hanifunny7]

It was really helpful thankkkkk you

[@real.psyched]

Thank you for watching

[@maximilyen]

Very well

[@pingukutepro]

Layer 1: Trash
Layer 2: Supplement
Layer 3: Supplement
Layer 4: Input
Layer 5: Output
Layer 6: Transport