Noradrenergic actions of Purkinje and locus coeruleus neurons in culture.

Explant cultures prepared from neonatal mice were used to study the actions of iontophoretically applied noradrenaline (NA) on Purkinje and locus coeruleus neurons, with extracellular and intracellular recording respectively. NA depressed spontaneous activity of Purkinje neurons and enhanced excitatory responses to glutamate in 14/16 cells. In cultures older than 26 days, NA hyperpolarized LC neurons but had no effect on or depressed depolarizing responses to glutamate. The hyperpolarizations were blocked by the selective alpha 2 antagonist yohimbine. Enhancement of glutamate responses is not a ubiquitous characteristic of NA action and appears not to be associated with alpha 2 adrenergic receptors.