A team of researchers from the National Center for Biological Sciences in Bangalore (India) has discovered that whether we are afraid or not is a matter of a “democratic vote” between the neurons in our brain . They decide by majority if we feel fear or not. The work has been published in the journal Nature Neuroscience .
To reach this conclusion, the scientists carried out an experiment with rats that were previously trained to fear a specific sound after which an electric shock would arrive – that sound anticipated punishment – and to be neutral before another type of sound that did not have consequences of any kind.
After learning to distinguish between the two sounds, the experts measured the electrical activity of their neurons – the basis of transmission of nerve impulses – discovering that with learning, electrical activity changed. Most neurons responded more intensely to the danger sound than to the other. Thus, each neuron was able to distinguish the sound associated with the threat , which determined the subsequent behavior of the rat. If the neurons that were altered were the majority, the rat felt fear . Apart from this, they discovered that there was a series of neurons, in a minority, that were altered with any of the sounds.
According to the study authors, in the amygdala, the part of the brain that processes fear, there is a minority of fearful neurons that any signal from the environment leads them to transmit a signal of panic but this does not affect subsequent behavior if that “democratic vote ”Does not activate it. Either way, when faced with a great threat, neurons respond alarmingly as a protective instinct.
