title: The insula modulates arousal-induced reluctance to try novel tastes through adrenergic transmission in the rat.
abstract: Reluctance to try novel tastes (neophobia) can be exacerbated in arousing situations, such as when children are under social stress or in rodents, when the new taste is presented in a high arousal context (HA) compared to a low arousal context (LA). The present study aimed at determining whether adrenergic transmission at the Insula regulates the reluctance to try novel tastes induced by arousing contexts. To this end, a combination of systemic and intra-insular manipulations of adrenergic activity was performed before the novel taste (saccharin 0.1%) was presented either in LA or HA contexts in rats. Our results show that systemic adrenergic activity modulates reluctance to try novel tastes. Moreover, intra-insular microinjections of propranolol or norepinephrine (NE) were found to modulate the effects of arousing contexts on reluctance to try novel tastes. Finally, intra-insular propranolol blocked epinephrine-induced increased reluctance, while intra-insular NE blocked oral propranolol-induced decreases in reluctance and increased the reluctance to try novel tastes presented in low arousing contexts. In conclusion, our results suggest that the insula is a critical site for regulating the effects of arousal in the reluctance to try novel tastes via the adrenergic system.
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Rojas
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Raúl
authors.initials: R
authors.lastname: Diaz-Galarce
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Jerez-Baraona
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Daisy
authors.initials: D
authors.lastname: Quintana-Donoso
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Moraga-Amaro
authors.affiliation: Laboratorio de Neurobiologia, Centro de Investigaciones Biomedicas, Universidad Andres Bello Santiago, Chile.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Stehberg
keywords: adrenergic activity; arousal; insula; insular cortex; reluctance; taste neophobia