Active Learning: A Practical Approach to Implementation

It’s likely that at this point I do not need to convince most of you that active learning can be highly beneficial to student learning.  There is a multitude of resources, including HAPS Educator articles, which discuss successful active learning in a variety of classroom settings.  But here’s the thing. With so many great ideas at our finger tips, where are we supposed to begin if we want to implement active learning in our own courses?  

GOALS

First, step back from the swarm of ideas swirling in your mind and reflect on your goals. What are the goals of your course (which may or may not be content-related)?  Your goals should shape the type of active learning exercise(s) you implement. Here’s what the participants at my workshop at the HAPS Annual Conference in May had to say about their goals with active learning:

Participants in a HAPS worskhop (May 2017) described their goals for active learning.
Participants in a HAPS worskhop (May 2017) described their goals for active learning.

 

PLAN

To ensure your efforts are manageable, start with just one or two sessions.  Upon successful implementation of the initial activity, you can build off it, or incorporating additional methods.  Allow enough time to develop the activity, implement it in class, and give yourself time afterward to assess and for providing student feedback if necessary.  Some (or all) of these steps can take a lot of time!

BUY-IN

This can be tough.  Students will sometimes resist the unfamiliar (i.e. not a standard lecture).  Be transparent.  Explain the goals of the activity, and if appropriate, share evidence to support the activity.  Ensure students that it is of the appropriate difficulty level for them and that you’re there to guide them.  Considering giving credit for participation, especially if it’s a regular part of class.  For more on this topic, check out the Cavannagh, et al. (2016) article or this blog post from Bryn Lutes at Washington University.

RESOURCES

Classroom Assessment Techniques: A Handbook for College Teachers by Angelo and Cross is a book that will walk you through identifying your goals, selecting appropriate activities for those goals, and it gives you a detailed guide for implementation of the activities and assessment.  Assessment is a critical part of scholarly teaching!  How else will you know if the original goals were accomplished?

Technology.  A simple, yet effective means of incorporating small snippets of active learning into a lecture can be interactive questions.  Similar to “clicker” questions, there are many web-based platforms which enable faculty to easily incorporate interactive questions (multiple formats) into lectures.  It’s an opportunity to give the students practice retrieving informing, as well as allowing instructors to see where students are in their understanding of the material.

Some audience response systems allow students to touch the correct answer on an image, and the data for the whole class shows up as a heat map!
Some audience response systems allow students to touch the correct answer on an image, and the data for the whole class shows up as a heat map!

Low-tech options.  In lieu of all of the apps and high-tech options out there we sometimes forget that a marker board, or pen and paper can be effective tools.  Drawing or writing out a process in a way that is meaningful to students (and maybe incorporating a drawing) is an effective means to promote learning.  Get creative with other materials too!  Pull ‘n’ Peel Twizzlers make a great model of vascular supply, and playdoh, pipe cleaners, paper, etc. can be used to model many different body parts.

While this is by no means an exhaustive list of resources available for us to use in teaching, I hope it helps you get started.  Establish your goals.  Pick an activity to meet those goals. Plan well, and don’t forget to include assessment!  Happy teaching!


Cavanagh, A.J.,  Aragón, O.R., Chen, X., Couch, B.A., Durham, M.F., Bobrownicki, A., Hanauer, D.I., & Graham, M.J. (2016). Student buy-in to active learning in a college science course. CBE Life Sci Educ 15(4).

Michael, J. (2006). Where’s the evidence that active learning works? Adv Physiol Educ 30: 159-167.

Pierce, R., J. Fox. (2012). Vodcasts and active-learning exercises in a “flipped classroom” model of a renal pharmacotherapy module.  American Journal of Pharmaceutical Education 76(10): 1-5.


Audra Schaefer is an Assistant Professor of Anatomy and Cell Biology who teaches neuroanatomy and histology to first year medical students.  She oversee multiple systems-based integrated courses that are part of the first two years in the medical curriculum.  She also conducts educational research, with interests in metacognition, study skills and remediation.

Getting Them out of Their Funk

Muscles and bones, bones and muscles. How many times have my students learned the deltoid tuberosity in the bone unit, only to complain that they have to learn all these bone names as part of their muscle attachments?! Many of my students come in thinking they are going to simply learn the names of the bones, having little understanding that there is a whole world of terms for bone landmarks. To help my novice students become proficient, I have made two changes.

muscle-attachmentsHistorically, my labs followed a 2 week period of appendicular and then axial bones, followed by a 2 week period of appendicular and then axial muscles. My students scraped an average of around 67% on their weekly practical quizzes. They always did slightly better with their bones, and then much worse with their muscles in part due to that muscle attachment component. I wanted more, so I flipped to appendicular bones one week, followed by appendicular muscles the next week. Their averages went up to 78% for the unit, but I still got a little of the whining related to bone landmarks. Their scores were higher on bone weeks and lower on muscle weeks, so I switched to regional study of the body, bones and muscles of the leg one week, the arm the next and so forth.  For the last three years, my averages for this unit have settled around 75%, but the students are making the connections between bone landmarks and their muscle attachments.

muscle-to-attachmentI remember when I took A&P, my lab instructor handed me a Rubbermaid with the bones for that week and said, “Get to it!” I had the “luxury” of having previously taken  Comparative Anatomy class, so 5 of my peers worked with me to learn the material. Most of my peers left lab and were overwhelmed. So when I started teaching A&P, I tried to help the students whose strategies mimicked my classmates’, but I kept running into an almost total mental shut down the moment I handed out their term list for the week. So I made a second change. Now my labs have 6 stations and students spend about 15-20 minutes at each station. Each station has an objective, which also helps the students chunk up the material into manageable pieces.

skeletonJust what can you do at these stations? One is the dissection/prosection table with the cadaver or cat. One is a pile of bones and they have to put Humpty Dumpty back together again – recognizing left vs right and what the bone names are. Another station has a plastic skeleton with felt muscles and scotch tape to study origin, insertion, action. I have brought in Halloween skeleton decorations and asked the students to look for anatomical inconsistencies. Another table has a few bones with the goal of identifying the landmarks from their list of terms.

You may be thinking that this doesn’t get to every student, but I have noticed is I now have students who either pass their lab quiz well, or they really, really don’t pass. There aren’t so many in the middle. It tells me the students who are studying, vs not spending the time studying and I have fewer students who are all out “tanking with pride,” as I call it. It seems to be working. A student came to me yesterday and told me that she had attempted to take A&P at another institution, but she got so lost in all the material, she didn’t know where to start. She felt my lab set up helped her divide and conquer the content into manageable pieces.

It’s easy to become complacent with our students, and forget that sometimes our students need ideas presented in a way that helps them begin to categorize and learn the material. What is so simple to us may be the straw that breaks the proverbial camel’s back for them.  It’s a lot of work to help our students figure out where to start and learn how to be a learner, but so rewarding when it works.


Nichole Warwick teaches biology at Clatsop Community College and is a proud member of the HAPS Communications Committee.

How does Physical Activity Exert Beneficial Effects on Atherosclerosis and Coronary Artery Disease?

This post describes an update seminar delivered by Harold Laughlin, Professor at the University of Missouri at the 2017 HAPS Annual Conference in Salt Lake City.


Update Seminar VII was given by Harold Laughlin.  In this talk, the benefits of exercise on cardiovascular health were clearly documented.  I’m sure we’ve all heard the sobering stats before.  Cardiovascular disease, largely due to atherosclerosis, is the leading cause of death in the USA, accounting for ~ 1/3rd of all deaths.  As our President-Elect Ron Gerrits announced, we were all left feeling very inspired to getting fit for the HAPS conference Fun Run next year!  

For those interested in a great review article on the regulation of coronary blood flow during exercise, Harold mentioned the Physiology Review article by Duncker and Bache (2008).   In particular, here is list of some of the things we know so far regarding coronary blood flow during exercise:

  • During exercise, heart rate and myocardial contraction increase to meet the increased oxygen demands of the body and heart itself.
  • In order to meet increased metabolic demand, coronary blood flow increases (~5 fold) and there is also a small increase in oxygen extraction.
  • An increase in heart rate, will increase the relative time spent in systole, which affects (impedes) coronary blood flow.
  • There are many factors which regulate coronary vessel dilation (neurohormones, endothelial factors, and myocardial factors)
  • During exercise, coronary vasodilation appears to be induced by many factors including: exercise-induced ischemia, shear stress, increased arterial pressure, tangential wall stress, higher levels of endogenous NO, and β-adrenergic activity.
  • Exercise training results in coronary microvascular adaptations including: the formation of new capillaries, increased arteriolar diameters, increased adrenergic receptor responsiveness, and increased endothelium-dependent vasodilation (as a result of increased expression of endothelial NO synthase (eNOS), increased NO production, and increased Kv (potassium voltage) channel activity).

In his talk, Harold brought up some current data from his experiments with swine vasculature (Simmons et al., 2012).  He noted that healthy individuals typically have good vasomotor tone, and express low levels of the inflammatory markers and adhesion molecules (e.g. E-selectin and vascular cell adhesion molecule-1, VCAM-1) that are associated with atherosclerosis.  It has been previously found that endothelial cells located at bifurcations and other points of turbulence, are more at risk for developing atherosclerotic plaques than straight conduit arteries (Davies et al. 2010).  Laughlin et al. (2012) decided to investigate the straight conduit arteries and veins in six different regions of the swine to determine whether there were any differences in susceptibility to the development of atherosclerosis.  Overall, they found conduit arteries expressed higher levels of both pro- and anti-atherogenic markers than veins.  Also as one might expect, vessels of healthy individuals that lack atherosclerosis, are the most responsive to exercise.

In this talk, the improvements in vasculature as a result of exercise training were specifically addressed (Green et al. 2017).  The exercise-induced effects on vasculature is actually remarkable.  It is estimated that physical activity increases longevity, and reduces the risk of cardiovascular mortality by 42-44%.  The positive effect of exercise is noted to have dose-dependent curve and exercise training has been found to be on par with contemporary drug interventions (Green et al. 2017).  Exercise induces structural and functional adaptations in the vascular walls that reduce the risk of atherosclerotic plaque formation.  In addition increased capillary density and formation of additional collateral circulation is observed, as exercise induces the release of VEGF (Vascular Endothelial Growth Factor) (Green et. al. 2017).  Also, exercise was found to increase endothelial progenitor cell (EPC) activity which contributes to the growth of new vessels as well as repair.

It is important to note that exercise training increases cardiac output and oxygen uptake, without increasing mean arterial pressure.  This is because as cardiac output increases, peripheral vasodilation occurs (reducing afterload).  Exercise training improves vasodilation capabilities through structural changes.  During exercise, the increased systolic pressure stimulates vascular endothelial and smooth muscle cells to grow and align in response to stress, allowing for greater vasodilation.  In addition, vessel wall stretching induces vasodilation through increased eNOS activity (which produces the vasodilator NO) and activation of Kv channels (which causes smooth muscle cells to hyperpolarize and relax).  In addition, increased blood flow, has been found to increase both acetylcholine and prostacyclin levels which have been shown to induce vasodilation.  Conversely, low levels of shear stress, has been found to increase expression of adhesion molecules (ICAM-1 and VCAM-1) and reduce levels of the endogenous vasodilator NO (Green et al. 2017).

Thankfully for those of us looking to improve vasodilatory function in our conduit arteries and increase our capillary density, improvements through exercise can be seen in as little as 1-4 weeks of exercise and of course continue with longer training sessions.  So with that in mind, I’ll be sure to grab my running shoes and sign my kids up for sports, as fewer than 30% of females and 50% of males get the recommended 60 minutes 5-7 days/ week of exercise!  Yikes-arama!  Time to unplug and play…

A big thank you to Harold Laughlin for a highly motivating talk!


Post from Dr. Zoë Soon, School of Health and Exercise Sciences, University of British Columbia Okanagan, BC, Canada


Davies, P.F., Civelek, M., Fang, Y., Guerraty, M.A. Passerini, A.G. (2010). Endothelial heterogeneity associated with regional athero-susceptiblity and adaptation to disturbed blood flow in vivo. Semin. Thromb. Hemost. 36, 265-275.

Duncker, D.J. and Bache, R.J. (2008). Regulation of coronary blood flow during exercise. Physiol. Rev. 88, 1009-1086.

Green, D.J., Hopman, M.T.E., Padilla, J., Laughlin, M.H., Thijssen, D.H.J. (2017). Vascular adaptation to exercise in humans: role of hemodynamic stimuli. Phsiol. Rev. 97, 495-528.

Simmons, G.H., Padilla, J., and Laughlin, M.H. (2012). Heterogeneity of endothelial cell phenotype within and amongst conduit vessels of the swine vasculature. Exp. Physiol. 97(9), 1074-1082.

Transferability: Giving Credit Where Credit is Due

In general, students take our A&P courses in preparation for a future career in healthcare or the sciences. It is critical to our students that our courses are accepted; either for transfer or as a prerequisite by other institutions and programs. National guidelines, such as the HAPS learning goals and outcomes, provide a common reference point for instructors and administrators to compare and evaluate courses. 

As an online science educator, one of my challenges is to make my courses as robust and defensible as possible when it comes to transfer. Unfortunately, a bias against online science courses still exists at some institutions. Some students are challenged or even denied credit for transfer or acceptance as a prerequisite simply because they took their course online. I agree that not all online science courses are equal and designed with the same rigor. However, the same can be said of on-campus courses, yet they are not held to the same level of scrutiny. 

In preparing this post, I went back to the HAPS-L Discussion Group archives to review the history of our discussions on the topic of transferability. Not familiar with the HAPS discussion groups? Visit the HAPS Discussion Groups page for additional information on how HAPS members can subscribe to the discussion groups and access the archives. 

In December 2015, we had a discussion on “Transfer credit for purely online A&P courses.” Wendy Riggs noted that at her institution, the teaching modality of the course was not allowed to be a factor when considering transfer. As long as the course had the appropriate number of credits, contained a laboratory component, and came from an accredited institution, it would be accepted for transfer. Both Wendy and Jon Jackson highlighted the important difference between focusing on the instructional method and achieving the learning outcomes. Jon Jackson made the point that asking if courses are equivalent is the wrong question. The appropriate question is how well the student in the course masters the material. 

Instructors and administrators can use the following questions to help guide their evaluation. Ideally, the syllabus should contain the answers to these questions:

Does the syllabus reference state or national standards? One of the goals of the HAPS Guidelines for Undergraduate Instruction of Human Anatomy And Physiology was to “help establish equivalency between anatomy & physiology courses at different institutions, easing many of the problems associated with the process of transferring credits.” A statement of course alignment to state or national standards can be very helpful during the evaluation process. References to articulation agreements may also provide an additional data point for comparison. 

Does the course use a commonly recognized textbook or course materials? The use of commonly recognized textbooks and course materials provides some confidence that the common body of anatomy & physiology knowledge has been covered in the course. This question becomes increasingly important as the use of Open Educational Resources (OER) becomes more common.

What was included in the lab? The HAPS Guidelines describe the expectations for hands-on laboratory experiences and hours of laboratory activity per week of the course. It is important to note that the HAPS Guidelines and the Distributed Learning Position Statement support A&P instruction at a distance. 

Does the course or department utilize the HAPS exams? Use of the HAPS exams provides a direct measure of student learning referenced to the HAPS learning outcomes. Even if individual student scores are not available, use of the HAPS exams for programmatic assessment is an indicator that the institution is attempting to evaluate student performance relative to the HAPS outcomes.

Is the institution regionally accredited? This may require investigation beyond the syllabus, but can be easily answered using the institution’s public website. Regional accreditation (HLC, SACS, etc.) provides an indication of overall institutional quality independent of instructional modality. 

Students can also be proactive and be prepared for potential questions:

Keep a copy of the syllabus. This is the most important document (besides the transcript) a student will need in order to demonstrate the scope and activities in our course.

Keep copies of their work. This is especially useful in courses where students are creating original lab reports or assignments. In my A&P courses, students create written and video-based lab reports. I encourage my students to keep copies of their assignments so that they can share them with institutions if there are questions. My institution also uses a commercial publicly viewable online portfolio platform which students can use to display their work. 

In summary, we can help all of our students with respect to transfer through quality course design and clear documentation in the syllabus. In terms of evaluating science courses for transfer, we need to take the time, request a syllabus, and give credit where credit is due.


Dave Brashinger is an assistant professor and director of the natural sciences program at American Public University System.

 

Action Potentials can be a Puzzle

I found myself digging through a closet of scrap-booking goods last night in a frantic effort to find a 1 3/8” hole punch. I had been sparked by an idea that has been percolating for years, but I’ve never implemented. I wanted to build a cell with ions, channels, and charges so my students could manipulate the “players” involved in the resting membrane potential and an action potential.

This concept is particularly challenging for students. They could use chemistry, biology, and elements of physics to understand this system, but mine are woefully under prepared. Their eyes glaze over when they have to think about electrical gradients and chemical gradients working simultaneously. Add in channel types and applications to graphs that describe membrane changes in voltage, and even I’m starting to have an anxiety attack! When I teach this concept, the energy in my classroom is so thick, I could cut it with a knife. There has to be a better way.

berfore-ap
Before…

But so far, no amount of restructuring, dividing, or attempting to present just a “snapshot” in time had worked to facilitate the connection between what is occurring with ions and how it happens. So I cut out a giant cell, a little positive and negative sign, and all the different channels, and put them in a bag. That handy scrapbook punch allowed me to make sets of 10 potassium ions and 10 sodium ions in the colors I have been trying to get my students to associate with this concept. Voila- my students will now have an intracellular space on a table that represents the extracellular space…and all the important pieces as well.

before-ap
…and after.

Back in the classroom, as I drew on the board a picture of each step of the electrical changes experienced by the cell, they had to manipulate their cell. Did it work dreamily well? Probably not. Some students got it and visibly relaxed. But some students didn’t get it…and remained in a state of panic. However, I did discover that my students were pretty mixed up by the concepts of “depolarization” and “repolarization.” Because they can’t see the cell, sometimes this creates a mental block.

After class, a subset of students followed me to my office, where we played more with the model and I’ll be darned if they didn’t get to the point where they could set up their cell appropriately for each of the phases of the action potential! I could ask questions like, “Can the cell be stimulated again at this point?” And the question I love more, “WHY!?!” Light bulbs started turning on and several students took pictures so they could make their own model at home to use while studying.

This week in lab we use the HHsim program to study action potentials and this time, my new models will be on the table with them and they are going to have to show me what happens to explain the graphical results they get. My hope is that time, coupled with this paper model, will help them master the concepts.


Nichole Warwick teaches biology at Clatsop Community College and is a proud member of the HAPS Communications Committee.

Join HAPS– for the conversations!

The HAPS Discussion group (also known as HAPS-L and before that as “the listserv”) is the place where the most interesting conversations in A&P are happening.  This discussion group has hundreds of members, is very active, and has often features amazingly high level conversations among leaders in the field.  This group was started in 1998 as an email listserv, and some still call it that, but it is a modern discussion group with email preferences and a web archive.  The HAPS discussion group is open to all current HAPS members and is one of the most valuable perks of membership.

This week, one discussion revolved around the most accurate classification of bone types. In this discussion, Mark Nielsen (University of Utah Anatomy Professor and winner of the 2017 HAPS-Theime Excellence in Teaching Award) shared multiple illuminating contributions to the conversation. Check out the excerpt below…and then imagine having content like THIS delivered to your email box on a regular basis.

WOW, there is a lot of interesting discussion going on here, this is one of the nice things about the HAPS listserve. It is always great to share and discuss. While I agree with many of the sage comments about classification and “does it really matter because the bones do not care or know where they fit in the scheme of things”, it is still important to recognize that there is correct and incorrect within a classification scheme. Following is the bases of the classification scheme:

Long bone = what is the one characteristic shared by long bones that none of the other bone types have, one thing and one thing only, a medullary cavity, and yes all the phalanges, even the small distal phalanges have a medullary cavity, as does the clavicle. The following bones have a medullary cavity:

  • clavicle
  • humerus
  • radius
  • ulna
  • metacarpals
  • proximal phalanges of hand
  • middle phalanges of hand
  • distal phalanges of hand
  • femur
  • tibia
  • fibula
  • metatarsals
  • proximal phalanges of foot
  • middle phalanges of foot
  • distal phalanges of foot

I believe someone stated that long bones are characterized because they have a diaphysis with proximal and distal epiphyses. This is not true. Many long bones only have epiphyses at one end and not the other. This is the case for many of the phalanges. Again, the characteristic that defines a long bone is the presence of a medullary cavity. Besides, many bones have epiphyses – for example, short bones and irregular bones have epiphyses.

Short bones = are characterized by a core of spongy bone with an outer covering of compact bone. They typically have a length, width, and depth that are approximately of equal dimensions. The carpal and tarsal bones are placed in this category.

Flat bones = the true flat bones of the body all reside in the skull, but the ribs are also often considered to fall in this category because their bone structure is similar to the flat bones of the skull. These are bones that are characterized by external and internal tables (laminae) of compact bone sandwiching dense trabecular diploe, the diploic spaces of the trabecular bone being filled with hemopoetic red marrow in the living subject. This would include the parietal bones, frontal bone, squamous portion of the occipital bone and temporal bone, sutural or wormian bones that are ossification centers that never fused with the fore mentioned bones.

Most of the remaining bones did not fit into one of these three categories. Like the short bones and flat bones all the remaining bones had an outer covering of compact bone and an internal core of spongy bone and no medullary cavity, but they were not short and they were not flat. This led to the next category that became the catch all:

Irregular bones = a variety of bone shapes consisting of an outer covering of compact bone and a central core of spongy bone, with some bone surfaces that are so flat and thin that they lack spongey bone completely e.g., the scapula, ethmoid. Most of the other bones fall in this category – vertebrae, the bones of the facial skeleton and inferior cranial vault bones, hyoid, malleus, incus, stapes, and the scapula and os coxae.

The final category is the sesamoid bones = these are bones that form within tendons. In human anatomy they are similar in bony structure to short bones but have a unique classification as sesamoid bones because of their location within tendons. In some other vertebrates they are very long slender bones within tendons.

One other recognized category is a pneumatized bone. These are bones that contain air spaces within their cores and can overlap with other categories. For example, the frontal bone is both a flat bone and a pneumatized bone. The ethmoid bone, sphenoid bone, and petromastoid part of the temporal bone are both irregular bones and pneumatized bones.

So there is a logic to classification and it is not a random thing that we can bend to our whims. We now have the choice to ignore it or teach it correctly.

So if you’re a HAPS member, by all means, join this discussion group. And if you’re not a member, JOIN HAPS so you can join the discussion group. (Then adjust your email settings, because most HAPSters have experienced the infamous “blown up email box” that results from some of the more rigorous conversations! Thankfully, executive director Peter English wrote a blog post with instructions for doing just that.)

Gene Targeting into the 21st Century: Mouse Models of Human Disease from Cancer to Neuropsychiatric Disorders

This post describes an update seminar delivered by Dr. Mario R Capecchi at the 2017 HAPS Annual Conference in Salt Lake City.


Update seminar VI was a special one, given by Nobel laureate, Mario Capecchi. Having survived World War II in Italy, in part as a homeless orphan, Mario’s life story is a fascinating one.  He went on to become a graduate student at Harvard in the lab of the Nobel Prize winner and co-discoverer of the structure of DNA, James Watson.  In 2007, Mario Capecchi, now at the University of Utah, won the Nobel Prize in Physiology or Medicine jointly with Oliver Smithies and Martin Evans for their work on gene targeting. The ability to create knock-out mice is widely used to this day and has been a valuable means of mapping gene function.  Mario’s research talk at this year’s HAPS conference focussed on his current work which involves characterizing the different roles that the HOX gene family of transcription factors play during mouse development.  While most HOX (homeobox) gene members are involved in controlling embryonic body plan development in a cranio-caudal manner, Greer and Capecchi (2002) found that Hoxb8 plays a unique role in the mouse’s grooming behavior.

Most animals, including humans, perform some type of auto-grooming and in mice, a cephalocaudal pattern occurs, where the head is groomed first and the tail is groomed last.  Many regions of the brain including the brainstem appear to be involved.  Greer and Capecchi (2002) found that mice with a homozygous Hoxb8 complete loss-of-function knock-out, exhibited over-grooming to the point of hair loss and formation of deep lesions. The deep lesions suggest that the mice also may have reduced sensitivity to painful stimuli.  These mice spent twice as long grooming as wild type mice and also over-groomed their control littermates to the point of inducing hair loss.  Interestingly, in humans, obsessive-compulsive disorder (OCD) often manifests as excessive cleanliness and grooming (e.g. trichotillomania).  Greer and Capecchi mapped the murine expression of Hoxb8 and found that expression began at E7.5 in the primitive streak and yolk sac, spreading through the developing spinal ganglia, spinal cord, and then throughout grooming regions of the CNS in the adult mouse.  In many animals, the basal ganglia has been shown to be involved in modulating grooming behaviour (Aldridge et al., 1993; Berridge, 1989; Berridge and Fentress, 1987; Cromwell and Berridge, 1996; MacLean, 1985a, 1985b; Stein et al., 1992; Wise and Rapoport 1989;).  

In 2008, Capecchi’s lab (Chen et. al., 2008) found that the Hoxb8 gene was normally expressed in microglia cells, and that this expression appears to be required for regulating normal grooming time.  Chen et al. (2008) found that grooming dysfunction in Hoxb8 knockout mice, could be rescued with wild-type bone marrow transplantation. This makes sense as microglia descend from hemocytoblasts.  In addition, Chen et. al. also found that the Hoxb8 gene was normally expressed in the spinal cord where it seems to be responsible for appropriate responses to nociceptive and thermal stimuli.  In fact, Holstege et al. (2008) proposed that the nociceptive recipient interneurons in the dorsal spinal cord laminae I and II are deficient and disorganized in Hoxb8 knockout mice leading to reduced sensation.  Furthermore, Chen et. al. (2008), found that bone marrow transplantation did not rescue sensory defects, indicating that these 2 pathways of dysfunction were due to separate deficiencies (i.e. microglia cell and sensory neurons). Chen et al. (2008) found that deletion of Hoxb8 only in the hematopoietic cells resulted in mice with excessive grooming, but normal sensory responsiveness.

It is unclear how microglia cells are involved in grooming behaviour, however “immunological dysfunction is linked to many psychiatric disorders including OCD, major depression, bipolar disorder, autism, schizophrenia, and Alzheimer’s disease” Ashwood et al., 2006; da Rocha et al., 2008; Kronfol and Remick, 2000; Leonard and Myit, 2009; Strous and Shoenfeld, 2006 (Chen et al., 2008).   In this study, Hoxb8 mutant mice were found to have a deficiency of microglia (i.e. fewer microglia in the adult brain).  In terms of how microglia may control behaviour, it is speculated that microglia may be involved in modulating synaptic transmission as they surround synapses, perhaps playing a role in adjusting levels of neurotransmitters (e.g. serotonin).  In addition, microglia cells can secrete cytokines that affect both neuronal activity and longevity.  

At first glance it may seem strange that immune system cells, such as microglia, are involved in grooming.  However, upon further reflection, it does make sense that grooming behaviours may be controlled by the immune system, as the purpose of grooming in animals is to reduce the number of harmful pathogens.

Finally, it was noted that the Hoxb8 mutant mice did exhibit high levels of anxiety.   Anti-anxiety drugs were found to reduce the anxiety-induced grooming behaviour in Hoxb8 mutant mice and also improved their ability to perform the open maze test (which is a frequent measure of anxiety).   

As you can see, a lot of really interesting data was relayed to us in this update seminar and I’d really like to thank Mario Capecchi for such a thought-provoking talk!


Post from Dr. Zoë Soon, School of Health and Exercise Sciences, University of British Columbia Okanagan, BC, Canada


Aldridge, J.W., Berridge, K.C., Herman, M., and Zimmer, L. (1993). Neuronal coding of serial order: Syntax of grooming in the neostratum. Psychol. Sci. 4, 391-395.

Ashwood, P., Wills, S., and Vand Water, J. (2006). The immune response in autism: a new frontier for autism research. J. Leukoc. Biol. 80, 1-15.

Berridge, K.C. (1989). Substantia nigra 6-OHDA lesions mimic striatopallidal disruption of syntactic grooming chains: a neural systems analysis of sequence control. Psychobiol. 17, 377-385.

Berridge and Fentress (1987). Disruption of natural grooming chains after stritopallidal lesions. Psychobiol. 15, 336-342.

Chen, S.-K., Tvrdki, P., Peden, E., Cho, S., Wu, S., Spangrude, G., and Capecchi, M.R. (2010) Hematopoietic origin of pathological grooming in Hoxb8 mutant mice. Cell 141, 775-785.

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