Talk:Cerebellum

Query regarding status of this article

The history of this article is not easy to understand. Am I correct that a draft was written by Rodolfo Llinas, converted to wikitext and edited by Javier Elkin, and then moved by Leo Trotter? Is Rodolfo actively curating this article? Thanks for any responses, William Skaggs 04:31, 23 July 2013 (UTC)

I do not know the history of the entry either, but it is apparent that the article is incomplete, in some respects. --Mario N. Negrello 16:56, 28 July 2013 (UTC)

Suggestions for Modifications and Additions

• • the introduction could mention the important fact that the cerebellar output is exclusively inhibitory.
  • the introduction motivates phylogeny but there's no session on comparative anatomy. I suggest adding one, perhaps with comparative pictures of unfolded cerebellum of different species (Sultan et al.)
  • the introduction should make reference to the olivo-cerebellar system (which perhaps deserves an entry too)
  • Anatomy deserves more attention. More diagrams. I could provide some nice showing the geometrical features of the cerebellar cortex (mostly from Braitenberg's classical 1958 article). The entry needs clearer and more detailed description of cerebellar anatomy.
  • Needs a section on development and morphogenesis
  • to make the point that the cerebellar architecture is stereotypical, the author ignores significant differences in anatomy and dynamics between different areas of the cerebellum (flocculus), and omits cell types.

(There are at least two cell types the entry omits: Lugaro cells and unipolar brush cells - excitatory on granules). It also ignores differences between flocculus and the rest of the cerebellum).

• • The sessions on cerebellar input systems need to be clearer, better referenced, and perhaps complemented with diagrams.
  • there is scarce information on the multifarious projections to and from the cerebellum and cerebellar system. More diagrams are needed here too.
  • particularly, the extensive projections from the dentate nucleus to the basal ganglia, and thereon to prefrontal cortex (articles from Schmachman, Strick, etc).
  • no mention of cerebellar zones, and the fact that they correlate with cell activity.
  • scarce reference made to conflicting views on cerebellar function.
  • There is surprisingly little about the purkinje cell, as in ion channel distributions, anatomical particularities and the like.
  • There's scarcely any mention of cerebellar pathology.
  • There's no mention of Marr-Albus-Ito anywhere in the text. A link to Marr would seem appropriate.
  • There's no mention of LTD or any other kind of cerebellar plasticity!
  • More quantified anatomy (perhaps comparing humans and mice)
  • Anatomy of Golgi cell dendrites, and the fact that they are contained within stripes (Zebrin).
  • The following is incomplete, as Golgi cells have also been shown to be inhibited by extracellular glutamate from spillovers:

The Golgi cells exert their inhibitory effect on the granule cells and thereby quench any further activity in the parallel fibers. This mechanism is one of negative feedback: through the Golgi cells, the parallel fiber extinguishes its own stimulus. The net result of these interactions is the brief firing of a relatively large but sharply defined population of Purkinje cells.

• • It would seem to me that the Inferior Olive would deserve a session, if not an article in itself. The cerebellum is better understood as the olivo-cerebellar system, and thus the article could make good use of detailed sessions both on the cerebellar nuclei and the inferior olive.

• It would seem like the pontine nuclei would merit a link?

---

--Mario N. Negrello 15:56, 28 July 2013 (UTC)

General Discussion

I agree with most of that, although I think it takes the anatomy to a level of detail that would better be dealt with in a subsidiary article. My reason for asking is that I would enjoy doing some work on this article and wanted to get a feel for whether there is any chance of revisions being approved. Regards, William Skaggs 16:56, 28 July 2013 (UTC)

Greetings William, Yes, i would also enjoy adding to the entry. I presume the editors would be happy with a more complete article. A set of subsidiary articles is a good idea. It would seem to me that these ones could be stubs:

• olivo-cerebellar system (containing also references to cerebellar theories)
  • IO, DCN, Pons
• purkinje cell

It feels to me like it would be more appropriate to have a parent page to cerebellum with the olivo-cerebellar system, including anatomy, dynamics and models of the Inferior Olive and of the Deep Cerebellar Nucleus.

Incidentally, I was considering writing an entry on the purkinje cell.

--Mario N. Negrello 16:59, 28 July 2013 (UTC)

Wikipedia's "cerebellum" article encapsulates my ideas about what an article on this topic should contain -- it is primarily my work. (I edit there under the name "Looie496".) The main exception is images, where I could not always find good ones and had to use what I could get. For a Scholarpedia article I think some parts of the Wikipedia article might not be necessary, and the material on theoretical issues could be expanded, since Scholarpedia promotes a focus on computational neuroscience. William Skaggs 19:58, 28 July 2013 (UTC)

Good points, I'll have a look in wikipedia and come back to you. Concerning pictures and diagrams i have accumulated a stash we could choose from, and particularly, some nice micrographies (GFP, brainbow), we could potentially use, i could get the approval for and off.

Concerning the computational emphasis, we are currently outlining an subsidiary article on the purkinje cell (Pascal Warnaar and I), which will make reference to existing models (starting with the famous De Schutter 1994), as well as dynamical profiles, bistability, ion channel distribution, and predictions.

--Mario N. Negrello 18:52, 31 July 2013 (UTC)

Post by Eugene Izhikevich (on behalf of an anonymous reviewer)

Although the article gives a good description of the biology of the cerebellum, it gives an incomplete account of the current knowledge. Also, it does not address important aspects such as cerebellar functions, plasticity and theories (model). In comparison, wikipedia's article is more detailed and accurate.

I believe that the current aspects should have been addressed in more details:

Anatomy:

Functional longitudinal organization of the cerebellum.

The connectivity should be more detailed, with distinction between vestibulocerebellum, spinocerebellum and cerebrocerebellum

Concept of micro zone and micro complex should be reviewed

Function

The cerebellar function should be review in greater details:

Sensorimotor role of the cerebellum (tuning of coordinated movement, learning, timing, etc.)

Non motor function of the cerebellum

Cerebellar plasticity should be reviewed.

The main theoretical and computational studies in relation with the cerebellar functions should be reviewed.

Also, the author should not focus so much on its own research and review some other works which may be contradictory to its own (7 citation out of 16 are from Llinas). For example, when the author claims that : "The fact that half of the cerebellar nuclear neurons are GABAergic and project to the inferior olive, as their only target underlines the importance of decoupling at the inferior olive as a central control system for motricity (Llinas, 2009).", he should also review alternative views on the possible reasons and implications of this connectivity. There are many examples like that through the article.

Finally, this article needs to cite more research papers to support its claims. For example, the author claims that "Purkinje cell … gives off recurrent collaterals that ascend back through the granular layer above and below the Purkinje somata and ultimately form synapses with Golgi and basket cells." without citing any work. (many examples through the article)

For all these reasons, I believe that Llinas article is not ready to be published as it is, and would require a consequent amount of work to address the points mentioned above in order to increase the quality of the review and meet scholarpedia's requirements.

Mario Negrello's Additions

changes

deep cerebellar nuclei -> cerebellar nuclei deep nuclei -> cerebellar nuclei

Mention to cognitive impairment from cerebellar damage in the introduction.

Added Unipolar brush cell as an 'ancient' component.

Added a section on Cerebellar Zones and Microzones

Added reference to Voogd, 2003 in the subsection on the congruence between the climbing and mossy fiber systems.

Added a section on synaptic plasticity - Added a figure on cerebellar plasticity sites (Gao et al., 2011)

Added a cerbellar zones figure

Added a section on Computational Models of the Cerebellum

Suggestion: add a link to LTD!

still to do

• thorough copy edit
• add selected references (i've listed most of them, must now go add them in the wikitext)
• upload figures
• modeling section needs review

• as Eugene suggested, a section on cerebellar contributions to motor function, a little review, including:
  • saccadic adaptation
  • eye blink conditioning
  • force field adaptation
  • visuomotor coordination
  • rhythm perception and production

Maybe an intermediate section between intro and anatomy, listing functions?