We have previously acquired high-resolution MRI scans of the brain, and the cutting procedure will hopefully result in a complete series of giant histological sections that will be treated to view and measure cellular-level features in the whole brain. This work is conducted in collaboration with Dr. Sam Ridgway of the National Marine Mammal Foundation.
Video Feed Programming (Pacific Daylight Time, PDT)
Tuesday August 16th: 3pm-6pm
Wednesday August 17th: 10am-1pm; 3pm-6pm
Thursday August 18th: 10am-1pm; 3pm-6pm
Friday August 19th: 11am-5:30pm
Saturday August 20th: 11am-until it is done...
There are many unanswered questions regarding the brain and mind of the bottlenose dolphin. We hope that the availability of a complete 3-D map at microscopic resolution will help solve some of the mysteries (and myths) surrounding dolphin cognition and intelligence.
Lately, we have witnessed an intense debate regarding the idea that the bottlenose dolphin may be too smart for captivity. This discussion is highly polarized and charged with very disparate personal views, feelings, and motives. The protagonists of this debate call, among other things, on the anatomy of this species to suggest that dolphins have human-like intelligence and therefore should receive the same ethical treatment and have the same legal rights as human beings. Indeed, in terms of relative size and complexity, the dolphin brain approaches that of men and women. However, I noticed that in the zealous quest to support the notion that dolphins are ‘people’ only the supposed similarities between the brains of humans and dolphins have been highlighted, not the differences that are many and very significant. For example, the dolphin brain contains more white matter with larger conductive axons. Auditory pathways that support echolocation are massive compared to human brains. The inferior colliculus is 12 times as large as equal sized human brains while the hippocampus is very small1. The relative expansion of the cerebellum is also dramatic2. Radically different thinking is likely because the corpus callosum connecting the two brain hemispheres is tiny compared to this structures in humans3. The blood supply to the two hemispheres is separate (separate blood supply facilitates sleep with one hemisphere while the other hemisphere is awake4). Understanding how dolphin behavior leverages on such distinctive neural architecture is one of the great challenges of comparative neurobiology.
Verba volant, scripta manent
The truth is, we know very little about how the brain of the (bottlenose) dolphin is organized structurally, and even less on how it works! Therefore, I chose a dispassionate perspective on the subject and plan to focus on creating anatomical images and data that will be the basis for future research and interpretations of behavioral studies. While theories on dolphin intelligence may change over time or be forgotten (verba volant; spoken words fly ), the information that is sealed within every histological glass slide will always be relevant and useful (scripta manent; written text stays). My lab’s role in this important debate is therefore to create new, permanent anatomical information so that current and future arguments over the rights of the dolphins will have richer and more rigorous scientific evidence to refer to.
It is The Brain Observatory’s tradition to be completely candid about the research that we conduct; accordingly, with permission from The Space and Naval Warfare Systems Command (SPAWAR) we have included a brief biography of MK. MK was born in the Mississippi Sound in or around 1970. In July 1974, he was recruited for the US Navy Marine Mammal Program and trained to be a mine-hunting dolphin. He participated in the program off the coast of the Point Loma peninsula in San Diego, CA. During the last year of his life, the animal failed to recover from a chronic, severe dermatitis despite various treatments delivered by the program veterinarians and animal care staff.
MK died at the age of 30 from an incurable skin disease. He was not sacrificed for the purpose of this study. Nevertheless, the circumstances leading to this scientific project will surely be debated and we would like to encourage this debate on our web site while the procedure is ongoing. Our position is that by conducting this work we are ensuring that the opportunity provided by the death of this animal is not wasted. Just like a human patient who, by donating their brain to research, can help others with his condition, we are going to do our best to make sure that MK’s brain donation will lead to an increased knowledge about the neuroanatomy and cognition of his species. We hope to make an objective contribution to the science of marine mammals and to the controversies that surround this field.
Jacopo Annese, Ph.D. (Dr. A)
Director, The Brain Observatory
1. Bullock, T. H., and V. Gurevich. 1979. Soviet literature on the nervous system and psychobiology of Cetacea. International Review of Neurobiology 21:48–127
2. Marino, L., J. K. Rilling, S. K. Lin and S. H. Ridgway. 2000. Relative volume of cerebellum in dolphins and comparison with anthropoid primates. Brain, Behavior, and Evolution, 56:204–211.
3. Tarpley, R. J., and S. H. Ridgway. 1994. Corpus callosum size in delphinid cetaceans. Brain, Behavior and Evolution 44:156–165.
4. Lyamin, O. I., P. R. Manger, S. H. Ridgway, L. M. Mukhametov and J. M. Siegel. 2008. Cetacean sleep: An unusual form of mammalian sleep. Neuroscience & Biobehavioral Reviews 32:1451–1484.