Changes in neurotransmitter amino acids content in several CNS areas from aggressive and non-aggressive bull strains

Neurotransmitter amino acid levels (glutamate, aspartate, GABA, and glycine) of crude synaptosomal fractions from several non-limbic CNS areas (pons, ventral tegmentum, midbrain reticular formation, fastigial nucleus of cerebellum, posterior colliculus and anterior colliculus) showed significant differences between aggressive Spanish fighting-bull and non-aggressive Friesian strains. The most unequal distribution was observed in neurotransmitter amino acids, while the non-transmitter amino acids (serine, isoleucine, leucine, threonine and alanine) showed minor and uneven changes. The results suggest a possible relationship between changes in amino acid neurotransmitter levels and the aggressive behavior observed in the aggressive breed.