Short- and Long-Term Social Recognition Memory Are Differentially Modulated by Neuronal Histamine.

Barbara Rani,Bruna Silva-Marques,Maria Beatrice Passani,Rob Leurs,Patrizio Blandina,Gustavo Provensi

doi:10.3390/biom11040555

Abstract

The ability of recognizing familiar conspecifics is essential for many forms of social interaction including reproduction, establishment of dominance hierarchies, and pair bond formation in monogamous species. Many hormones and neurotransmitters have been suggested to play key roles in social discrimination. Here we demonstrate that disruption or potentiation of histaminergic neurotransmission differentially affects short (STM) and long-term (LTM) social recognition memory. Impairments of LTM, but not STM, were observed in histamine-deprived animals, either chronically (Hdc−/− mice lacking the histamine-synthesizing enzyme histidine decarboxylase) or acutely (mice treated with the HDC irreversible inhibitor α-fluoromethylhistidine). On the contrary, restriction of histamine release induced by stimulation of the H3R agonist (VUF16839) impaired both STM and LTM. H3R agonism-induced amnesic effect was prevented by pre-treatment with donepezil, an acetylcholinesterase inhibitor. The blockade of the H3R with ciproxifan, which in turn augmented histamine release, resulted in a procognitive effect. In keeping with this hypothesis, the procognitive effect of ciproxifan was absent in both Hdc−/− and αFMH-treated mice. Our results suggest that brain histamine is essential for the consolidation of LTM but not STM in the social recognition test. STM impairments observed after H3R stimulation are probably related to their function as heteroreceptors on cholinergic neurons.

Highlights

Introduction published maps and institutional affilThe term social memory encompasses two different cognitive processes
Neither the disruption nor the potentiation of the histaminergic transmission altered natural social preference, suggesting that neuronal histamine does not play a key role on mice sociability
In analogy to Hdc−/− mice, animals that received αFMH and ciproxifan spent similar percentage of time exploring the familiar and the novel social stimuli (Figure 7C). These results clearly indicate that administration of a selective H3 R antagonist can potentiate social discrimination memory, but it requires an intact brain histamine system to accomplish this effect in mice

Summary

Introduction

Introduction published maps and institutional affilThe term social memory encompasses two different cognitive processes. The second, social recognition, is defined as the ability to recognize a familiar or novel conspecific [1] These processes are of paramount importance for social species since the accurate recognition of a specific individual associated with the interpretation of specific environmental cues lead to the unfolding of the appropriate behavioral response such as: approach, investigation, attack or mounting [2]. All these complex, either cooperative or competitive, behaviors have been selected and persisted during the evolution due to their key roles for social hierarchy, mate and offspring recognition, territorial defense, interspecies recognition, and for the general establishment and maintenance of groups [3].

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Conclusion