Figure 5.

Model summarizing the opposing effects of prenatal hypo- and hyperthyroidism on TC axonal branch and EPB steady-state dynamics in adult V1. The probability of TC synapse losses or gains is schematized for each experimental group. TC synapses are more likely to be lost in mice with prenatal hypo- (Hypo/MMI) or hyperthyroidism (Hyper/LT4) versus control mice (Norm/VEH). However, the prevalence of large-scale branch retractions is greater in mice with prenatal hyperthyroidism as synapse loss was only mediated by smaller-scale changes in EPBs for mice with prenatal hypothyroidism. The probability of TC synapse addition through the growth of distal branches and EPB growth on more proximal regions is increased in both mice with prenatal hypo- and hyperthyroidism. However, the probability of gaining new synapses is greatest in mice with prenatal hypothyroidism due to a significant increase of branch growth over control mice.