Suzuka Iritani (left) and Minasa Kasai (right) finished their excellent undergrad studies. Suzuka demonstrated that the hippocampus of seals is smaller when compared to their land-living relatives, the Carnivores. Minasa did a histological analysis of the dolphin’s amygdala. Well done! Suzuka will continue with her Master studies in our lab.
Whales and dolphins lose heat to their aquatic environment 90 times faster than terrestrial animals in air.
Even a slight drop in brain temperature makes many neurons inactive, greatly reducing mental activity. In a recent study we demonstrate that whales and dolphins possess a specialized brain heat-producing system to combat this environmental pressure of heat loss. They have the internal chemistry that allows the brain to function as its own heating element.
Proteins called uncoupling proteins (UCPs) are involved in this internal heat production by preventing efficient ATP production for normal neuronal functions and instead convert this energy as heat. Results of the study showed that 90% of the neurons in whale and dolphin brains contain UCPs, much more than closely related species (such as the river hippopotamus that only has 35% of UCP containing neurons).
30 to 70% of glia cells of whales and dolphins contain UCPs, which is 30% denser than other related species. Furthermore, nerve terminals that contain the neurotransmitter noradrenaline are about 30% denser in whale and dolphin brains when compared to closely related species. Noradrenaline is involved in processes that control the concentration and activity of UCPs.
These findings show that cetaceans have an increased ability for thermogenesis due to higher expression of UCPs. These heat-regulation mechanisms may have contributed to the evolution of large brain size in whales and dolphins.
Jinta Kasai has finsihed his Master thesis. All the best for your new job!
We are happy to announce that this year we will be participating in Hokkaido Summer Institute with 2 new courses:
Undergraduate level: Fundamentals of Comparative Neuroanatomy and Behaviour: from birds to whales
The objective of this course is to give the students an overview of the different ways the brain and behaviour evolved in separate, but closely related vertebrate classes.
Postgraduate level: Mammalian Brain Morphology: From specimen collection to mathematical modeling
The aim of this course is to demonstrate the use of an integrated set of multidisciplinary methods, ranging from neuroanatomy to MRI (Magnetic Resonance Imaging) processing to theoretical modeling, to better understand brain morphology of large mammals (e.g. Whales).
In a serious of publication in the Journal of Comparative Neurology, in collaboration with the laboratory of Paul Manger, University of the Witwatersrand, South Africa, we examined the anatomy of the amygdala, the diencephalon and the hippocampus of the feliform banded mongoose and the caniform domestic ferret.
Minasa (left) and Suzuka (right) are 4th year students who joined our lab this April. Minasa will be working on the amygdala of whales and Suzuka will analyses the hippocampus of Pinnipeds. Welcome and good luck!
This talk has been postponed to a later date. The new date will be announced as soon as it is established!
Dr. Hiromasa Takemura, from the Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology in Osaka, will present his exciting research on white matter pathways. 6th of March in Room 407 (4th fl.) – Science #5 bld. 15:00 -16:00. Everyone is welcome!!!
Our new addition to the lab: a 3D printed Baird’s beak whale (40% original size, left) and Sika deer brain (70% of original size, right).
Nina was invited to give a talk at the 41th annual meeting of the Japanese Society for Comparative Physiology and Biochemistry (JSCPB2019), Symposium: Comparative and evolutionary approaches toward understanding the brain architecture. Tokyo, Japan
Phua Yong Heng and Suzuka Iritani are Biology undergraduate students who joined our lab this October as Technical Assistants. A big welcome!