Washington, September 3 : A new study suggests that humans have a higher cognition than other mammals because they possess different types of cells, and not due to having larger cells.
Published in the journal PloS Biology, the study focused on chandelier cells, so-named for their structural resemblance to an old-fashioned candlestick.
Tamas, the lead author of the study, says that the study provides new insights into the organization and function of neocortex, a brain region involved in sensory perceptions, conscious thoughts, and language.
During the study, the researchers studied the microcircuitry of neocortical cells by recording from pairs of connected neurons in human brain tissue.
The challenging method allowed them to measure the dynamic communication lines between neurons, illustrating how neurons interact and affect one another, say the authors.
Contrary to the suggestion that neurons worked in groups to affect the brain, the study showed that a single chandelier cell could trigger multiple excitatory pyramidal cells that make up the bulk of the cortex, and cause a chain reaction throughout the brain.
The authors said that triggering specific chandelier cells enabled the researchers to elicit a precisely timed chain of electrical events in the neocortex.
The study also revealed that the synaptic pathways between chandeliers and pyramid cells are much stronger than has been recorded previously in other mammals.
Based on their observations, the researchers have come to the conclusion that humans do possess different types of cells, and that our higher cognition is not due to having larger cells.
Though chandelier cells have been found in other species, they are more complex in humans.
The authors of the study say that this fact raises the possibility that there are many things that attribute to higher cognition - different types of cells, and a complex circuitry, perhaps.
This study furthers the search for the answers to higher cognition, and more fully opens the door to questions of how our brains compare to those of other species.