We have studied nicotinic acetylcholine receptors in spontaneously hypertensive 'stroke prone' (SHsp) rats. We found a significant decrease in I-125-alpha-bungarotoxin binding and alpha 7 subunit mRNA levels in cortical areas of the SHsp rats with respect to Wistar Kyoto (WKy) normotensive rats. Antihypertensive drug treatment counteracted these changes in cerebral cortex but not in hippocampus. No significant change was instead found in [H-3]-epibatidine binding and alpha 4 and beta 2 subunit mRNA levels. SHsp rats showed decreased latency at the active avoidance test and transiently increased threshold at both hot-plate and tail-flick tests in comparison with WKy rats. None of these behavioral parameters was correlated with I-125-alpha-bungarotoxin binding in cortical areas. In conclusion, present data show a preferential impairment of alpha-bungarotoxin sensitive nAChRs in SHsp rats. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.