Talk:Whisking pattern generation

Review of ‚Whisker Pattern Generation’ by Phil Zeigler and Asaf Keller

This article provides an overview over a field which, unfortunately, is characterized by large gaps of knowledge. The authors do a great job in covering the most important background information and some of the speculative hypotheses that have been formed about whisker pattern generation so far. For the non-expert reader I think, however, the article is a bit too dry. Some illustrations of the rather complex anatomical and functional background of pattern generation would be helpful. Also some reference to other (better described) pattern generation systems would help to see how whisking locates in a greater picture of pattern generation. In some instances more references to the existing literature might be given to guide the readers seeking more detailed information.

Comments:

1) I recommend to include a schematic to the description of the whisking machinery in section 1. It is a complicated affair and non-expert readers may be helped tremendously if there were a picture to look at.

2) In section 2 the somatotopic arrangement of the facial nucleus and its connectivity is detailed without reference to the existing literature. Here some references would be helpful.

3) In section 3, paragraph 2, line 1: ‘is’ should read ‘in’

4) A schematic about the most prominent, and important connectivity of the facial nucleus would be helpful somewhere in section 3.

5) In section 3 it is stated that brainstem stimulation evokes whisker movements. A reference should be included.

6) In section 4.1, paragraph 2 it is stated that rats use different motor strategies to discriminate objects. The paper of Carvell and Simons (1995) explicitly studying this question should be cited.

7) In section 4.2 the abbreviation IOx is introduced and used only one time. I recommend to use the full description. Also the abbreviation IO can be confused with inferior olive. Better use ION.

8) Section 4.2. paragraph 2. This paragraph is an interesting one, detailing first data on sensitive periods for whisking during development. Unfortunately it is written in a rather confusing way and should be reformulated. What does ‘re-sectioning’ and ‘re-emergence’ mean? Is there repetitive sectioning of the nerve? The puzzling finding that before the presumed sensitive period, sectioning of the nerve has no effect should be explained better. etc.

9) Section 5.1. Arguably the most detailed and supported hypothesis about the whisker pattern generator is the serotonin hypothesis by Keller. It is an idea that departs quite a bit from principles known from better established systems (see next comment). Some ideas how the serotonin mechanism could solve some of the pertinent problems of whisker patterns generation e.g. coordination between sides or protraction-retraction, could be added.

10) Section 5 could be greatly improved and made more accessible by adding schematics that contrast the emerging knowledge about the whisker pattern generator against the properties of some better established systems – for instance the CPGs for breathing or locomotion.

11) Section 5.3. My lab has shown first evidence that intensity of stimulation in RW, the whisking area of vMCx, can change the whisking frequency (Haiss and Schwarz, 2005). In addition, the same work has shown that RF the other area of vMCx can adjust the set point.