Abstract: | Administration of l-dopa to unilaterally 6-hydroxydopamine-lesioned rats, activates the early gene c-fos in the lesioned caudate-putamen. D-1 receptor blockade by SCH 23390, preventedl-dopa-induced Fos-like immunoreactivity in the whole caudate-putamen, while D-2 receptor blockade by raclopride reduced Fos-like immunoreactivity only in the dorso-lateral portion. The results suggest thatl-dopa induces c-fos primarily through an activation of D-1 receptors, while D-2 receptor stimulation plays a facilitatory influence on D-1 mediated c-fos expression. |