Central 6-OHDA affects both open-field exploratory behaviour and the development of hypertension in SHR.

To investigate the possible relation between changes in behaviour and the development of hypertension in the spontaneously hypertensive rat (SHR), the effect of intracerebroventricular (ICV) administration of the catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) on blood pressure and spontaneous behaviour was studied. In addition to an attenuation of the rise in blood pressure in SHR, 6-OHDA induced a marked decrease in rearing activity in the open field towards levels found in WKY. Other parameters were either not changed (stereotyped sniffing) or influenced in a comparable way in SHR and WKY (increase in locomotion). These results suggest that ICV 6-OHDA may simultaneously affect the development of hypertension and certain components of the changed behaviour of SHR. The exact relation between the two phenomena awaits further investigation.