Yves Agid

While I agree with the authors that glia are under-researched and undervalued in neuroscience, this book falls short of its promise. The biggest with the book is how it is written. It is a very shallow overview, seemingly aimed at lower year undergraduate students. The book wastes a lot of time explaining very simple brain anatomy and function (in some cases so simplified as to be incorrect). My thinking is that if you're interested enough in glia to buy an Oxford book about them, then you don't need the primer. In that way I was disappointed. Along these lines, the size of the book and the reference list are both more slender than I'd like.

Another thing that ticked me off was that Agid and Magistretti completely wrote off the contribution of microglia in the preface. They wave their hands, say that microglia are no different from other macrophages, and pronounce astrocytes as the "heroes of our story". I've written a review paper for a master's level class on how microglia affect memory and cognition. I can tell you from my own knowledge - microglia do a hell of a lot, and their role is so much more complex than macrophagic activity. This book's validity and longevity are seriously impaired by this glaring omission. Agid and Magistretti's refusal to consider the microglia in cognition is just another instance of "neuro-chauvinism" (their term).

When introducing the astrocyte's role in learning, two main chemical players are introduced. Serine and lactate. The idea of serine is interesting: it must bind to the NMDA receptor (key mechanism of LTP) alongside neuronal glutamate, and serine is released from astroglia. However, serine as a gliotransmitter was debunked at least five years before this book was released (Wolosker et al. 2016). The enzyme that produces serine, serine racemase, is almost exclusively expressed in neurons, meaning that serine mainly a neurotrasmitter and astrocytes are superfluous in this particular aspect of plasticity.

I'm not saying astrocytes aren't involved in learning and memory, far from it. It's just that there's no excuse for poor arguments from outdated research in a book written in this era, in which there is so much excellent work on glia. At any rate, of two putative plasticity mechanisms, one is not actually mediated by astroglia. Lactate is an interesting avenue, though again, not all lactate is astrocytic in origin. An interesting paper shows that exercise derived lactate can drive memory formation via BDNF (El Hayek et al., 2019). Overall though, the case for astrocytic lactate is obscure but getting stronger over time. At any rate, I don't want to nitpick the content too much.

When it comes to the production of the book, I have some issues. The figures look like they were sketched on the back of a bar napkin. Why a book like this doesn't either use a skilled scientific illustrator or actual photographs of structures is beyond me. Additionally, without proofreading, I encountered too many grammar mistakes. I can't fault the authors here, only OUP's dramatically lowering standards.

Pettily, I'll bring up that the book is guilty of many rhetorical questions as section titles or topic sentences. As always, we can invoke Betteridge's law ("Any headline that ends in a question mark can be answered by the word no"). An example: "Could consciousness be glial?"... nope (it's clearly more complex - and they know it). This writing style is disingenuous, not suited for an academic work.

I should give credit where credit is due however. It does justice to the fragmented and unclear involvement of astrocytes in neurological disease, and encourages researchers to continue considering astroglia in looking for solutions. As well, I found their discussion of astrocytes as a kind of diffuse syncytium (being all connected via gap junctions) really interesting. We are long overdue for books that celebrate the many roles of glia. The last chapter is a fun meditation on why as neuroscientists we've missed glia for so long. I liked this: "neuroscience operates as an ideology", it certainly does. Although this book is far from the ideal, I have to give it up to the authors for making an effort to spread awareness of these often maligned cells that do so many interesting and vitally important things for neuronal maintenance and for cognition. As researchers who aim to understand how higher cognition arises from physiological activity we must leave no stone unturned. Here's to even more in the future.

References:
El Hayek, L., Khalifeh, M., Zibara, V., Abi Assaad, R., Emmanuel, N., Karnib, N., El-Ghandour, R., Nasrallah, P., Bilen, M., Ibrahim, P., Younes, J., Abou Haidar, E., Barmo, N., Jabre, V., Stephan, J. S., & Sleiman, S. F. (2019). Lactate Mediates the Effects of Exercise on Learning and Memory through SIRT1-Dependent Activation of Hippocampal Brain-Derived Neurotrophic Factor (BDNF). The Journal of Neuroscience, 39(13), 2369–2382. https://doi.org/10.1523/JNEUROSCI.166...

Wolosker, H., Balu, D. T., & Coyle, J. T. (2016). The Rise and Fall of the d-Serine-Mediated Gliotransmission Hypothesis. Trends in neurosciences, 39(11), 712–721. https://doi.org/10.1016/j.tins.2016.0...
(less)… (més)