Control of behaviour and brain noradrenaline neurons by peripheral blood volume receptors.

A moderate blood volume load or experimental hemorrhage caused in the conscious rat reciprocal alterations in locomotor activity and norepinephrine turnover in brain regions largely innervated by nucleus locus coeruleus. Other brain regions as well as other central neurotransmitters (dopamine, 5-hydroxytryptamine) investigated did not show similar reciprocal changes. These data taken together with previous electrophysiological evidence support the notion that peripheral blood volume receptors participate in the control of brain norepinephrine neurons in the locus coeruleus as well as behaviour.