The allele symbols on the outside of the punnett square represent the alleles in the gametes . Because when we done cross we got the gametes only . Example AABB X aabb , then we got the gametes AB and ab . This represent AB and ab are the alles of the gamete only . A allele is the alternative form of gene , if one is dominant other one is recessive.
GABA(gamma amino butyric acid) is an inhibitor neurotransimitter. When it attaches to the post-synaptic segment it causes an influx of anions that makes is harder to generate an action potential.