NORADRENALINE AND POTENTIATION IN THE CHICK BRAIN SLICE

THE role of the noradrenergic system as a modulator of neurotransmission in the chick forebrain was investigated in brain slices containing the medial hyperstriatum ventrale, an area known to be involved in learning and memory. The alpha(2)-agonist clonidine (20 mu M) decreased the post-synaptic response to local stimulation at 0.1 Hz, while activation of, beta(2) receptors increased this response. Induction of persistent potentiation following stimulation at 5Hz was blocked by drugs (20 mu M ICI 118,551; 20 mu M propranolol) which showed preferential antagonistic activity at the beta(2) receptor but not by the beta(1)-preferential antagonist timolol. This effect may be due to an interaction with the NMDA receptor system.