Table 4: Intrahippocampal administration of drugs that act on the histaminergic system and memory performance.

SpeciesHippocampal siteBehavioral taskHistaminergic modulatorEffect on memoryReference(s)

Rat1DorsalInhibitory avoidanceHistamine [140]
Rat2VentralOne-way active avoidanceHistamine [141143]
RatDorsalOne-way active avoidanceHistamineUnaffected[143]
Rat2, 3DorsalEight-arm radial mazeHistamine[78]
Rat4IntrahippocampalRadial mazeHistamine [80]
RatDorsalInhibitory avoidanceH2 receptor agonist (dimaprit) [140]
Rat5VentralActive avoidanceH3 receptor antagonist (clobenpropit) [144]
RatDorsalContextual fear conditioningH2 receptor agonist (amthamine) [145]
RatDorsalContextual fear conditioningH3 receptor agonist (RAMH) [145]
Rat3DorsalEight-arm radial mazeH3 receptor antagonist (clobenpropit) [146]
RatDorsalThree-panel runwayH1 receptor antagonist (pyrilamine) [147]

RAMH: (R)-(−)-alpha-methylhistamine
1Effect reverted with concomitant administration of the H2 receptor antagonist ranitidine
2Effect reverted with concomitant administration of the H1 receptor antagonist pyrilamine
3Impairment induced using intrahippocampal injection of MK-801
4Impairment induced using intraseptal injection of muscimol
5Impairment induced using intrahippocampal injection of scopolamine.