The Big Bang of the Human Brain - on the Making of the Brain and the Emergence of Consciousness
Thursday 14 May 2009
to 16:15 at
Professor Hugo Lagercrantz (Professor of Pediatrics, Karolinska Institute)
The quest for the emergence of the human brain and its consciousness belongs to one of the key puzzles confronting scientific worldview. The neural tube may be formed by a default pathway three weeks after conception. The cranialpart is "ballooning" due to induction by the sonic hedge-hog protein. 10-20 weeks after conception about 200 000 new neurons are formed per minute. The
neurons sprout and become connected via synapses. Synaptogenesis is stimulated by sensory input and peaks during early childhood (1 million newsynapes every second!).
The infant brain is more like a jungle than a computer. There is a redundancy of neuronal branches. Optimal pathways are selected due to activity and epigenetic mechanisms.
The newborn brain is not blank as earlier believed. The physicist Peter Fransson has together with us demonstrated that there is a spontaneous resting activity in the cortex by the use of functional MRI.
The newborn infant seems to be aware of itself and to a limited extent of the surrounding world, ie he/she is probably conscious.