Blockade of nucleus basalis magnocellularis or activation of insular cortex histamine receptors disrupts formation but not retrieval of aversive taste memory.
Recent research, using several experimental models, demonstrated that the histaminergic system is clearly involved in memory formation. This evidence suggested that during different associative learning tasks, histamine receptor subtypes have opposite functions, related to the regulation of cortical cholinergic activity. Given that cortical cholinergic activity and nucleus basalis magnocellularis (NBM) integrity are needed during taste memory formation, the aim of this study was to determine the role of histamine receptors during conditioned taste aversion (CTA). We evaluated the effects of bilateral infusions of 0.5 microl of pyrilamine (100 mM), an H(1) receptor antagonist, into the NBM, or of R-alpha-methylhistamine (RAMH) (10 mM), an H(3) receptor agonist, into the insular cortex of male Sprague-Dawley rats 20 min before acquisition and/or retrieval of conditioned taste aversion. The results showed that blockade of H(1) receptors in NBM or activation of H(3) receptors in the insular cortex impairs formation but not retrieval of aversive taste memory. These results demonstrated differential roles for histamine receptors in two important areas for taste memory formation and suggest that these effects could be related with the cortical cholinergic activity modulation during CTA acquisition.
Purón-Sierra
Liliana
L
Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla, No. 3001 Juriquilla, Querétaro, Qro. 76230, Mexico.
Sabath
Elizabeth
E
Nuñez-Jaramillo
Luis
L
Miranda
María Isabel
MI
D000818:Animals; D020532:Basal Nucleus of Meynert / Q000187:drug effects / Q000502:physiology*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D017442:Histamine Agonists / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D008297:Male; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology*; D008761:Methylhistamines / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011968:Receptors, Histamine / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000378:metabolism; D018100:Receptors, Histamine H3 / Q000378:metabolism; D055697:Taste Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D017442:Histamine Agonists; D006634:Histamine H1 Antagonists; D008761:Methylhistamines; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D018100:Receptors, Histamine H3; C069357:alpha-methylhistamine; D011738:Pyrilamine