This study shows that the number of mature neurons in the human amygdala increases from childhood into adulthood. The authors suggest that this trajectory may be due to the incorporation of immature neurons from the paralaminar nucleus in the ventral amygdala. In contrast, individuals with autism spectrum disorder show an initial excess of mature neurons followed by a decline into adulthood. The results suggest a degenerative component in autism spectrum disorder and highlight the need for a more comprehensive understanding of the protracted cellular development of the human amygdala for multiple psychiatric disorders.
Avino TA, Barger N, Vargas MV, Carlson EL, Amaral DG, Bauman MD, Schumann CM: Neuron numbers increase in the human amygdala from birth to adulthood, but not in autism. PNAS 115 (14) 3710-3715 (2018).