Aetna CEO: Obamacare In A 'Death Spiral' Heading Into 2018. Aetna and Humana have called off their deal amid government concerns over competition. Here's a look back at six pivotal moments that led to this. Aetna and Humana have called off their deal amid government concerns over competition.
For the plant genus, see Synapsis (plant). Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
For example, the rate of synaptogenesis in the visual cortex peaks between 2 and 4 months postnatally, and the peak number of synapses is reached by approximately 8 months. On the other hand, the peak number of synapses in the middle frontal gyrus does not occur until sometime between 12 and 15 months of age.