Organization of the Catecholaminergic System in the Short-Lived Fish Nothobranchius furzeri.

Janina Borgonovo,Camilo Allende-Castro,Patricio Ahumada-Galleguillos,Pablo Henny,Alejandro Oñate-Ponce,Miguel L Concha

doi:10.3389/fnana.2021.728720

Abstract

The catecholaminergic system has received much attention based on its regulatory role in a wide range of brain functions and its relevance in aging and neurodegenerative diseases. In the present study, we analyzed the neuroanatomical distribution of catecholaminergic neurons based on tyrosine hydroxylase (TH) immunoreactivity in the brain of adult Nothobranchius furzeri. In the telencephalon, numerous TH+ neurons were observed in the olfactory bulbs and the ventral telencephalic area, arranged as strips extending through the rostrocaudal axis. We found the largest TH+ groups in the diencephalon at the preoptic region level, the ventral thalamus, the pretectal region, the posterior tuberculum, and the caudal hypothalamus. In the dorsal mesencephalic tegmentum, we identified a particular catecholaminergic group. The rostral rhombencephalon housed TH+ cells in the locus coeruleus and the medulla oblongata, distributing in a region dorsal to the inferior reticular formation, the vagal lobe, and the area postrema. Finally, scattered TH+ neurons were present in the ventral spinal cord and the retina. From a comparative perspective, the overall organization of catecholaminergic neurons is consistent with the general pattern reported for other teleosts. However, N. furzeri shows some particular features, including the presence of catecholaminergic cells in the midbrain. This work provides a detailed neuroanatomical map of the catecholaminergic system of N. furzeri, a powerful aging model, also contributing to the phylogenetic understanding of one of the most ancient neurochemical systems.

Highlights

The catecholaminergic (CAergic) system has aroused particular interest due to its role in a variety of neural functions, including motor control, memory, learning, reward, motivation, sleep, temperature regulation, and reproduction (Crocker, 1997; Hurley et al, 2004; Salamone and Correa, 2012)
The main subdivisions of the brain, the localization of brain nuclei, and the neuroanatomical terminology used in this paper is based on D’Angelo (2013), the only available brain atlas of adult N. furzeri
It is important to bear in mind that this classical paradigm differs from the prosomeric model proposed by Puelles and Rubenstein (2003), where the forebrain is divided into three caudorostral segments (p1, p2, and p3), and a secondary prosencephalon

Summary

Introduction

The catecholaminergic (CAergic) system has aroused particular interest due to its role in a variety of neural functions, including motor control, memory, learning, reward, motivation, sleep, temperature regulation, and reproduction (Crocker, 1997; Hurley et al, 2004; Salamone and Correa, 2012). Catecholaminergic System in Annual Killifish imbalances in catecholamines or components of the CAergic system are present in neuropsychiatric disorders such as schizophrenia, depression, and anxiety (Joyce, 1993; Davis et al, 1994), and in neurodegenerative diseases with high prevalence as is the case of Parkinson’s disease (PD; Dawson and Dawson, 2003). The CAergic system deteriorates in the course of physiological aging, showing an age-dependent loss of neuronal components in the locus coeruleus (LC; Manaye et al, 1995), striatum (Huot et al, 2007), and retina (Roufail and Rees, 1997). Together, these findings reveal that the CAergic system’s deterioration is a cross-cutting issue of normal and pathological aging

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