caa a22 4500 606201912 CHVBK 20210128100950.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00429-014-0739-3 doi (NATIONALLICENCE)springer-10.1007/s00429-014-0739-3 The noradrenergic projection from the locus coeruleus to the cochlear root neurons in rats [Elektronische Daten] [Sebastián Hormigo, Ricardo Gómez-Nieto, Orlando Castellano, M. Herrero-Turrión, Dolores López, José de Anchieta de Castro e Horta-Júnior] The cochlear root neurons (CRNs) are key components of the primary acoustic startle circuit; mediating auditory alert and escape behaviors in rats. They receive a great variety of inputs which serve to elicit and modulate the acoustic startle reflex (ASR). Recently, our group has suggested that CRNs receive inputs from the locus coeruleus (LC), a noradrenergic nucleus which participates in attention and alertness. Here, we map the efferent projection patterns of LC neurons and confirm the existence of the LC-CRN projection using both anterograde and retrograde tract tracers. Our results show that each LC projects to the CRNs of both sides with a clear ipsilateral predominance. The LC axons terminate as small endings distributed preferentially on the cell body and primary dendrites of CRNs. Using light and confocal microscopy, we show a strong immunoreactivity for tyrosine hydroxylase and dopamine β-hydroxylase in these terminals, indicating noradrenaline release. We further studied the noradrenergic system using gene expression analysis (RT-qPCR) and immunohistochemistry to detect specific noradrenergic receptor subunits in the cochlear nerve root. Our results indicate that CRNs contain a noradrenergic receptor profile sufficient to modulate the ASR, and also show important gender-specific differences in their gene expression.3D reconstruction analysis confirms the presence of sexual dimorphism in the density and distribution of LC neurons. Our study describes a coerulean noradrenergic projection to the CRNs that might contribute to neural processes underlying sensory gating of the ASR, and also provides an explanation for the gender differences observed in the behavioral paradigm. Springer-Verlag Berlin Heidelberg, 2014 Acoustic startle reflex nationallicence Gender differences nationallicence Neuronal tracers nationallicence Noradrenergic receptors nationallicence Sensory gating nationallicence 3D reconstruction nationallicence Hormigo Sebastián Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut Gómez-Nieto Ricardo Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut Castellano Orlando Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut Herrero-Turrión M. Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut López Dolores Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut de Anchieta de Castro e Horta-Júnior José Department of Anatomy, Biosciences Institute, São Paulo State University-UNESP, 18618-970, Botucatu, São Paulo, Brazil aut Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1477-1496 1863-2653 220:3<1477 2015 220 429 https://doi.org/10.1007/s00429-014-0739-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00429-014-0739-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hormigo Sebastián Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut NATIONALLICENCE 700 1- Gómez-Nieto Ricardo Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut NATIONALLICENCE 700 1- Castellano Orlando Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut NATIONALLICENCE 700 1- Herrero-Turrión M. Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut NATIONALLICENCE 700 1- López Dolores Neuroscience Institute of Castilla y León, University of Salamanca, 37007, Salamanca, Spain aut NATIONALLICENCE 700 1- de Anchieta de Castro e Horta-Júnior José Department of Anatomy, Biosciences Institute, São Paulo State University-UNESP, 18618-970, Botucatu, São Paulo, Brazil aut NATIONALLICENCE 773 0- Brain Structure and Function Springer Berlin Heidelberg 220/3(2015-05-01), 1477-1496 1863-2653 220:3<1477 2015 220 429