0000000000591046
AUTHOR
Bernardita Cádiz-moretti
Sex pheromones are not always attractive: changes induced by learning and illness in mice
A male-specific major urinary protein named darcin is attractive to female mice, Mus musculus, stimulates a learned attraction to volatile components of a male's urinary odour and induces spatial learning. In this article we show that darcin also induces learned attraction for a previously neutral olfactory stimulus (the odorant isoamyl acetate), acquired by repeated presentation of both stimuli together. We hypothesize that this is a case of olfactory–vomeronasal associative learning, in which darcin acts as the unconditioned reinforcer. However, the presence of darcin is not always attractive to adult female mice. Urine from males parasitized by the nematode Aspiculuris tetraptera has no …
Neural Substrate to Associate Odorants and Pheromones: Convergence of Projections from the Main and Accessory Olfactory Bulbs in Mice
In rodents olfactory stimuli are essential for socio-sexual behaviour. Volatile stimuli mainly activate the main olfactory system, whereas non-volatile ones, some of them considered as pheromones, activate the accessory olfactory system. Traditionally, it has been considered that the efferent projections of the main and the accessory olfactory bulbs innervate different telencephalic areas. Recent studies performed in rats and mice have challenged this view. In this work we explore in mice, through the use of anterograde tracer injections in the olfactory bulbs, the brain centres where olfactory and vomeronasal information might converge.
Differential efferent projections of the anterior, posteroventral, and posterodorsal subdivisions of the medial amygdala in mice
The medial amygdaloid nucleus (Me) is a key structure in the control of sociosexual behaviour in mice. It receives direct projections from the main and accessory olfactory bulbs, as well as an important hormonal input. To better understand its behavioural role, in this work we investigate the structures receiving information from the Me, by analysing the efferent projections from its anterior (MeA), posterodorsal (MePD) and posteroventral (MePV) subdivisions, using anterograde neuronal tracing with biotinylated and tetrametylrhodamine-conjugated dextranamines.The Me is strongly interconnected with the rest of the chemosensory amygdala, but shows only moderate projections to the central nucl…
Afferent and efferent projections of the anterior cortical amygdaloid nucleus in the mouse
The anterior cortical amygdaloid nucleus (ACo) is a chemosensory area of the cortical amygdala that receives afferent projections from both the main and accessory olfactory bulbs. The role of this structure is unknown, partially due to a lack of knowledge of its connectivity. In this work, we describe the pattern of afferent and efferent projections of the ACo by using fluorogold and biotinylated dextranamines as retrograde and anterograde tracers, respectively. The results show that the ACo is reciprocally connected with the olfactory system and basal forebrain, as well as with the chemosensory and basomedial amygdala. In addition, it receives dense projections from the midline and posteri…
Afferent and Efferent Connections of the Cortex-Amygdala Transition Zone in Mice
The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that …