The endogenous lipid messenger oleylethanolamide facilitates fear memory and releases histamine from basolateral amygdala
Year: 2016
Type: conference-paper
Abstract: Neuronal histamine participates to oleoylethanolamide hypophagic effects. Since histamine is involved in \nmnemonic processes, we investigated if brain histamine is also required for oleoylethanolamide-induced \npromnesic effects. \nWistar rats (280-300 g) were submitted to contextual fear conditioning, and immediately after received an \noleoylethanolamide injection (10 mg/kg, ip). Memory was assessed 72 hours after injections. \nOleoylethanolamide-treated animals showed a longer freezing time (255.3±48.5 s; n=11) as compared to \nsaline-treated animals (176.6±34.4 s; n=8). Pretreatment with the histamine biosynthesis inhibitor alpha- \nfluoromethylhistidine (5 μg, i.c.v.) prevented such effect (150.7±61.3 s, n=9). A reduction of freezing time \nwas observed in oleoylethanolamide-treated rats after intra-BLA infusions with the H1R antagonist \npyrilamine (0.9 μM 142.4±35.4 s, n=7) or H2R antagonist zolantidine (0.1 μM 132.5±51.7 s, n=10) as \ncompared with controls (247.4±55.2 s, n=10). Using microdilysis technique we observed an increase of \nHA release (up to 120%, basal HA release, 66.8±23.1 fmol/15min, n=5) from the BLA of freely moving \nrats after oleoylethanolamide i.p. injection at the same dosage used in the behavioural paradigm. But not \nfrom the hypothalamic ventromedial and paraventricular nuclei, whereas it decreased histamine release \nfrom the prefrontal cortex and nucleus accumbens. The involvement of histamine in the BLA, in \noleoylethanolamid-induced promnesic is suggested.
Author: BLANDINA, PATRIZIO
Language: English
Topic: Memory and Neural Mechanisms
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7028176367