Reduced activity of locus coeruleus neurons in hypertensive rats.

The influence of blood pressure on locus coeruleus (LC) neuronal activity was investigated in chloral hydrate anesthetized rats. Mean spontaneous firing rate of LC neurons was reduced by 25% in deoxycorticosterone acetate (DOCA-salt) treated Sprague-Dawley rats and by 19% in spontaneously hypertensive rats (SHR) as compared to their corresponding control animals. In acute experiments performed on normotensive rats, peripherally induced blood pressure changes elicited reciprocal changes in cell firing of the majority of LC neurons. The findings suggest that LC may have a role in long-term regulation of blood pressure.