[Animal experiment]-Comparing the brains of different primates suggests the reasons why humans become special

  A detailed comparison and analysis of the human brain and other primate brains revealed important evolution, such as these changes related to the neurotransmitter dopamine. In order to determine the differences between the brains of different primates, AndréM.M. Sousa et al. analyzed the transcription profiles of 247 tissue samples, representing hippocampus, amygdala, striatum, medial dorsal nucleus of thalamus, and cerebellar cortex. create. And 11 areas of the neocortex; these tissue samples were collected from 6 individuals, 5 chimpanzees and 5 macaques. They found that in at least one brain region, a total of 11.9% of mRNA and 13.6% of miRNA showed up- or down-regulation of human-specific transcripts. However, of all the brain regions analyzed in this study, of the 3154 protein-coding genes that are uniquely regulated in the human body, only 22 are up-regulated and 9 are down-regulated. Of particular note is the discovery that the two genes encoding human brain dopamine biosynthesis enzymes are tyrosine hydroxylase (TH) and dopa (3,4-dihydroxybenzene).

  Alanine) Decarboxylase (DDC). Dopamine is known to be involved in many aspects of cognition and behavior, including working memory, reasoning, reflexive exploratory behavior, and overall intelligence. This up-regulation of dopamine-related genes prompted researchers to quantify and compare TH+ interneurons in 45 adult brains from 9 primates. The authors confirmed that humans have a higher number of TH+ interneurons in the dorsal caudate and putamen (striatum) compared to the non-human primates analyzed in this study. The author discusses possible explanations for differences in TH + neurons in these brain regions (for example, this may be related to neuronal migration and differentiation).