It seems to be the common rule that the younger we are when we try to learn something new, the better we are at acquiring the necessary skill. Our human performance is therefore a reflection of the neural circuitry that has been developed by early experiences. Yes, we are capable of learning new things when we are adults; however, it appears that those who have started younger, fare better. This is caused by the fact that we have certain critical or sensitive periods in our early development that allow us to learn. Before we continue, let me first give two definitions by T.K Hensch. “A critical period (CP) is a strict time window during which experience provides information that is essential for normal development and permanently …show more content…
These studies examined the loss of responsiveness in V1 and thanks to these studies, as well as with the help of molecular tools, researches have managed to determine the cellular mechanisms involved in the onset and closure of critical periods. The cellular mechanisms involved in CP plasticity are split into four cellular substrates: CP triggers, mediators, brakes and reopeners. Immature neural circuits can be made plastic with the help of molecular triggers like Otx2 and BDNF, which cause a CP to open. The neurotransmitter GABA is involved in the maturation of these neural circuits and underlies the timing of plasticity. The plasticity switch that controls the opening of the CP is the parvalbumin (PV) cell. This is an inhibitory cell and a positive subtybe of GABA neuron, which determines whether plastic changes are possible by means of an excitatory-inhibitory balance. This balance is crucial in determining the timing of the CP. It is conceivable to either trigger or delay CP onset when GABA function is manipulated. One can either accelerate GABA function by using pharmacological agents like benzodiazepines to open the CP quicker, or delete genes involved in GABA synthesis or cause a disruption in the environment to delay the opening of the