“…In vivo, neonatal hypothyroidism results in an increased number of astrocytes and Bergmann glia in the rat cerebellum and hyperthyroidism produces the opposite effect (Clos & Legrand 1973). In vitro, thyroid hormone has been reported to affect astrocyte morphology, GFAP organization and glutamine synthetase activity and expression (Aizenman & de Vellis 1987, Gavaret et al 1991, Trentin & Moura Neto 1995, Trentin et al 1995, Lima et al 1997, Calloni et al 2001 in addition to the regulation of protein phosphorylation (Ruel et al 1986) and glucose transporter (Roeder et al 1985, 1988, Ruel & Dussault 1985. In astrocytes, thyroid hormone is also involved in the regulation of extracellular matrix organization, growth factor secretion, and cell proliferation (Trentin & Moura Neto 1995, Trentin et al 1995, 2001, Lima et al 1997, Farwell & Dubord-Tomasetti 1999b, Martinez & Gomes 2002.…”