Week 4: Osteometrics and Odaiba

Hello from the PRI! As week 4 comes to a close, I am finishing up with the osteometric data collection from the skeletal samples. Since the Japanese macaque collection is so expansive, I can be very specific about sampling. Each skeletal sample requires approximately 85 different measurements once I have semi-rearticulated and sided the skeleton. These measurements are taken from both crania and postcrania, so each sample must be relatively complete and intact.

 Nutrient Foramina and Bone Growth

As I have previously mentioned, my research focuses on developmental bone biology. I am interested in seeing how the environment in Japan interacts with the genotype of the Japanese macaque during development through the physical manifestation of that genotype, also known as the ‘phenotype’. One way of keeping track of bone growth through development is to look at the nutrient foramen. Every bone has a nutrient foramen, or a small opening into the bone which allows for veins and arteries to supply the bone with blood to help it grow. On long bones (the limbs), these are found in the shaft, always directed away from the growing end of a bone. In the upper limb, the growing ends are in the proximal end of the humerus, and the distal ends of the radius and ulna. In the lower limb, the growing ends are found in the distal femur and proximal tibia. So, when I am measuring long bones, two measurements are taken from the nutrient foramen; one from the foramen to the distal end and the other from the foramen to the proximal end. This quantifies how much growth has occurred from the nutrient foramen.

Bone Density Techniques

I previously mentioned that some of my measurements involve weights, and you might be wondering what the importance of weighing bones would be. This is another method of quantifying how much grow has occurred, in terms of bone density. It is used when measurements of shape might not be as accurate due to irregularities in bone appearance. Another method of examining robusticity is by using a pQCT scanner, or peripheral quantitative computed tomography. Multiple slices from the midshaft of the femur from each sampled skeleton will be produced to look at the density of the bone by comparing cortical thickness. Each slice takes approximately 15 minutes, so this is an extremely time-consuming process, but is a non-invasive way of observing the internal architecture of a bone.

Nerd Nite at the PRI

This past Thursday, I attended a fun and educational evening hosted by the PRI called Nerd Nite Inuyama. It takes place once a month and involves casual lectures interspersed with different sensory experiences! The theme this month was called Chasing the Phantom: Brain tricks, magic shadows, and delusion. Four different professors, post-docs, and PhD students shared lectures including one on the neurobiology of hallucinations to determine if Japanese monkeys could see chimpanzee ghosts. Another lecture discussed the use of natural drugs by fauna in the wild. For example, the mushroom called Amanita muscaria is a hallucinogenic commonly consumed by reindeer, which then urinate while other reindeer consume the urine, apparently to get the same hallucinogenic effects. Only approximately 15% of the compound is metabolized by the liver, leaving 85% in the urine! It is thought that this is where the notion of “flying reindeer” comes from.

Another Weekend in Tokyo

Since Tokyo is such a large and sprawling city, I decided to spend a second weekend there to explore different districts! On Saturday, after a quick trip to the top of the 47-story Caretta Shiodome for an incredible view of Tokyo, some JSPS fellows and I went to Odaiba to experience the Borderless exhibit at the teamLab Digital Arts Museum. It was an incredible sensory experience that included map-free exploration of continuously changing, flowing exhibits and a non-traditional tea house where you chose from a variety of green teas to experience “flowers” blooming in your cup and petals falling away with each sip.

The day ended with my first experience at the Ōoedo-onsen-monogatari, a carnival-style onsen in Odaiba. Onsen are hot soaking pools filled with water sourced from geothermal springs, which are common in Japan due to the volcanic activity. This onsen was special because there is a central area decorated to look like a night market where you dress in traditional yukata and walk around playing games and eating food between baths! It was an incredible, relaxing experience.

Before heading back to Inuyama, I made a quick stop through Akihabara, which is known for video games, anime, and manga culture. There were multistory buildings that were dedicated arcades. While here, I tried taiyaki, which is a fish-shaped pancake/waffle type confection that is filled with either red bean paste, or flavored custard. They were delicious!

Until next time, Sayonara!


This research is supported by the Japan Society for the Promotion of Science