Histaminergic Mechanisms for Modulation of Memory Systems

Table 4

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

Species	Hippocampal site	Behavioral task	Histaminergic modulator	Effect on memory	Reference(s)
Rat^1	Dorsal	Inhibitory avoidance	Histamine	↑	[140]
Rat^2	Ventral	One-way active avoidance	Histamine	↓	[141–143]
Rat	Dorsal	One-way active avoidance	Histamine	Unaffected	[143]
Rat^2, 3	Dorsal	Eight-arm radial maze	Histamine	↑	[78]
Rat^4	Intrahippocampal	Radial maze	Histamine	↑	[80]
Rat	Dorsal	Inhibitory avoidance	H2 receptor agonist (dimaprit)	↑	[140]
Rat^5	Ventral	Active avoidance	H3 receptor antagonist (clobenpropit)	↑	[144]
Rat	Dorsal	Contextual fear conditioning	H2 receptor agonist (amthamine)	↑	[145]
Rat	Dorsal	Contextual fear conditioning	H3 receptor agonist (RAMH)	↑	[145]
Rat^3	Dorsal	Eight-arm radial maze	H3 receptor antagonist (clobenpropit)	↑	[146]
Rat	Dorsal	Three-panel runway	H1 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.