Effects of brain histamine on memory deficit induced by nucleus basalis-lesion in rats.

AIM

To investigate whether or not brain histamine was involved in memory deficits induced by lesions of nucleus basalis magnocellularis (NBM) in rats.

METHODS

Passive avoidance response was used to measure memory process in rats, and NBM was bilaterally lesioned by injection of ibotenic acid (6 microg/site).

RESULTS

Icv injection of histamine (500 ng), and ip injection of histidine (1500 mg/kg), metoprine (10 mg/kg) or tacrine (3, 5 mg/kg) ameliorated memory impairment induced by NBM lesion regarding passive avoidance response. The ameliorating effect of histidine was antagonized by pyrilamine (2-5 mg/kg), a H1-antagonist, but not by zolantidine, a H2-antagonist.

CONCLUSION

Histaminergic neurons play an important role in learning and memory via H1-receptor, and its action may be due to cholinergic neurons.