SALBUTAMOL OVERCOMES THE EFFECT OF THE NORADRENERGIC NEUROTOXIN DSP-4ON MEMORY FUNCTION IN THE DAY-OLD CHICK

These experiments investigated the effect of the relatively selective noradrenergic neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) on memory formation in day-old chicks trained on a discriminat ed passive avoidance task. A time course study showed that DSP-4 treat ment resulted in amnesia as early as 20 min post-learning. In a second study, a series of alpha- and beta-adrenergic agonists (noradrenaline ; the alpha 1 agonist phenylephrine; the beta 1 agonist dobutamine; an d the beta 2 agonist salbutamol) were applied immediately after the tr aining trial. Both noradrenaline and salbutamol were effective in amel iorating the memory deficits caused by DSP-4 treatment, and in consoli dating weakly reinforced training. These studies support the notion th at noradrenaline subserves a vital role in the consolidation of memory in the chick, and that the beta 2 receptor subtypes are principally i nvolved in the intermediate phase of memory formation.