Sex differences and asymmetries of catecholamines: relation to turning preferences.

Male and female Sprague-Dawley rats were tested for turning preferences in a multiple alley maze. The left and right caudate-putamen were dissected and assayed for norepinephrine and dopamine. Dopamine was not found to be lateralized contralateral to turning preference for females as a group. However, dopamine was significantly lateralized contralateral to the females turning preference if a strong turning bias was present. No relationship between dopamine asymmetry and turning preference was evident for males. Females were found to have norepinephrine significantly lateralized to the left caudate-putamen; in males greater striatal norepinephrine levels were equally distributed between left and right sides. This sexual dimorphism in norepinephrine lateralization was not related to turning preference.