Festive Virtual Poster Event focused on Neuronal Histamine

THURSDAY 16th December 2021 12.00-13.30 CET

Programme of the Symposium: EHRS_Festive_20211216_Program

Abstracts: EHRS_Festive_Program&Abstract

Title: Diet prevents social stress‐induced maladaptive neurobehavioral and gut microbiota changes in a histamine‐dependent manner

Author: Barbara Rani (University of Florence, Italy, barbara[dot]rani[at]unifi[dot]it)

Abstract: In this study, we demonstrated a new role for brain histamine as a mediator of the beneficial effects of PUFA/vitamin‐A enriched diet against the cognitive and neurochemical disruptions caused by chronic stress. To this aim, we used Hdc‐/‐ and Hdc+/+ mice. Social defeat stress, a validated model of chronic stress in mice, induced social avoidance, memory impairment, affected long term‐potentiation in the hippocampal CA1 region, caused changes in microbiota profile, oxylipins expression of both Hdc‐/‐ and Hdc+/+ mice. Dietary supplementation since weaning prevented stress‐induced deficits only in Hdc+/+ mice. Histamine deficiency prevented almost all of these diet‐related beneficial effects.

PDF: Barbara Rani

Title: Chemogenetic activation of histaminergic neurotransmission improves memory expression

Author: Alessia Costa (University of Florence, Italy, alessia[dot]costa[at]unifi[dot]it)

Abstract: To interrogate the function of brain histamine we chemogenetically activated the histaminergic neurons in HDC‐Cre mice. Specifically, HDC‐Cre mice were injected bilaterally into the TMN with excitatory DREADDs or related control, to transfect histaminergic cells. The mice were then tested for social, spatial and fear memories followed by DREADDs activator Clozapine‐N‐Oxide (CNO) injection. Here, we observed a memory improvement in all tested tasks when histaminergic cells were chemogenetically activated.

PDF: Alessia Costa

Title: Unravelling the role of histamine neurons in memory processes through chemogenetics: potential sex differences

Author: Lola Hardt (Bordeaux University, France, lola[dot]hardt[at]u‐bordeaux[dot]fr)

Abstract: Histamine is a known modulator of memory processes. Previous studies were based on histamine receptors pharmacology or histamine depletion which have inherent limitations, restricting the ability to clearly separate the implication of histamine transmission between consolidation and retrieval. Our study thus used a chemogenetic approach in order to specifically silence histaminergic neurons during either memory formation or retrieval in three different long‐term memory tasks, i.e. Object Recognition Memory (ORM), Inhibitory Avoidance (IA) and Social Recognition Memory (SRM), in both males and females. Chemogenetic histamine modulation specifically during training impairs ORM at 48h but not 24h, independently of sex. Similar manipulations during IA training or retrieval have an opposite effect in both sexes at 7 days but not 48h,attenuating retention in males but enhancing it in females. Finally, histaminergic neurons silencing had no impact on SRM assessed at 24h in males (with sex differences as SRM was not effective in females at 24h). Our results confirm the implication of histamine in memory consolidation and further indicate an additional form of implication in later consolidation stages necessary for long‐term memory persistence. Moreover, our results stress the complexity of histamine implication in those processes through the discovery of opposite sex effects of histamine neuron inhibition in the aversive memory task.

PDF: Lola Hardt

Title: 3D reconstruction of brain wide neuronal circuits involved in aversive memory following a‐fluoromethylhistidine

Author: Alessandra Franceschini (University of Florence, Italy, franceschini[at]lens[dot]unifi[dot]it)

Abstract: The central histaminergic system is an important modulator of memory related to adverse events. Researchers have proved that the histamine neurotransmitter is necessary for long‐term memory (LTM) but not short‐term memory of step‐through inhibitory avoidance (IA). Our aim is to understand how neuronal patterns, involved in formation and storage of fear memory, change with a histamine depletion using whole brain mapping of c‐fos expression.

PDF: Alessandra Franceschini

Title: Maternal administration of the histamine H 1 receptor (H1R) antagonist/inverse agonist chlorpheniramine affects rat offspring cerebral cortex development

Author: Rocío Valle‐Bautista R (Centro de Investigación y de EstudiosAvanzados del Instituto Politécnico Nacional, México, rociovb26[at]gmail[dot]com)

Abstract: Histamine increases deep‐layer pyramidal neurons (DLPN) differentiation of the neocortex through H1R activation, while chlorpheniramine (Chlor) decreases neuronal differentiation during early corticogenesis in the rat. To explore possible long‐term effects of the maternal administration of Chlor during DLPN differentiation, we evaluated postnatal changes on neurons, cytoarchitecture and function of the primary motor cortex in the offspring.

PDF: Rocio Valle Bautista

Title: Search of the way of MAO‐B inhibition by the known histamine H3 receptor ligands

Author: Agnieszka Olejarz‐Maciej (Jagiellonian University, Poland, agnieszka[dot]olejarz[at]uj[dot]edu[dot]pl)

Abstract: Dual‐targeting ligands (histamine H 3 receptor and MAO‐B inhibitors) are reported to be a promising approach for the treatment of Parkinson’s disease. We chose the most active dual‐target ligands from our Library for more detailed MAO‐B inhibition studies. For this purpose, the reversibility and modality of the inhibition were examined and results were compared with reference MAO B inhibitor(s) showing a similar inhibition pattern.

PDF: Agnieszka Olejarz-Maciej

Title: Dual histamine H 3 and sigma‐1 receptor ligands as novel pharmacological tools in the treatment of central nervous system disorders with the focus on neuropathic pain

Author: Katarzyna Szczepańska(Jagiellonian University, Poland, szczepanskatarzyna@gmail.com)

Abstract: Recent studies have shown that some clinically evaluated histamine H3 receptor (H3R) antagonists possess nanomolar affinities at sigma‐1 receptor (σ1R) binding sites, and therefore we selected twenty representative structures among our previously reported H3R ligands to investigate their affinity at σRs. Most of the tested compounds interact with both sigma receptors (σ1R, σ2R) to different degrees. Interestingly, ligands KSK68 and E377 turned out to be high‐affinity histamine H3 and σ1 receptor antagonists with negligible affinity at the other histamine receptor subtypes and promising antinociceptive activity in vivo.

PDF: Katarzyna Szczepańska

Title: An overview of histaminergic signaling in Amyotrophic Lateral Sclerosis

Author: Savina Apolloni (Fondazione Santa Lucia Istituto di Ricovero e Cura a Carattere Scientifico, Italy, Savina.Apolloni@uniroma2.it)

Abstract: Amyotrophic lateral sclerosis (ALS) is a late‐onset neurodegenerative disease that primarily affects motor neurons. We identified some histamine‐related genes that are deregulated in the spinal cord of patients with ALS and we showed that the pharmacological increase of the histamine content in transgenic ALS mice decreases neuroinflammation, reduces death and dendritic spine loss in motor neuron, and increases mice life span. Moreover, by a network‐based algorithm for drug repurposing, we identified histaminergic drugs as potential innovative solutions for ALS therapy.

PDF: Savia Apolloni