Catecholaminergic anatomy.

<p>Tyrosine hydroxylase (TH) immunoreactivity (ir) was used as a marker for catecholaminergic neural populations. (<b>A</b>) The bilateral noradrenergic locus coeruleus (LC). (<b>B</b>) (inset) Dorsal view of midshipman brain with relative positions of A, C, D. (<b>C</b>) Representative caudal (<b>C</b>) and rostral (<b>D</b>) sections of the dopaminergic periventricular posterior tuberculum (TPp). <b>Abbreviations:</b> Fourth ventricle (IV); Paraventricular organ (PVO); Third ventricle (III). Scale bar = 50 µm (LC) and 100 µm (TPp).</p

Co-activation of auditory/vocal-acoustic nuclei and CA neurons.

<p>Pairwise correlations between numbers of cFos-ir neurons in auditory/vocal acoustic nuclei and percent colocalization of cFos-ir within tyrosine hydroxylase (TH-ir) neurons of locus coeruleus (LC) (<b>A–E</b>) and the periventricular posterior tuberculum (TPp) (<b>F–J</b>). Closed circles are males exposed to social signals; open circles are males exposed to ambient noise; green trend lines indicate significant correlations (<i>p</i>≤0.05).</p

Auditory and vocal-acoustic anatomy.

<p>Transverse sections with DAPI nuclear counterstain (blue) showing white borders around nuclei in which numbers of cFos-ir neurons were quantified within auditory and vocal-acoustic pathways. The caudal (<b>A</b>) and rostral (<b>B</b>) extents of the rostral intermediate descending octaval nucleus (DOri). The caudal (<b>C</b>) and rostral (<b>D</b>) extents of the periventricular nucleus centralis of the torus semicirularis (TSnc). (<b>E</b>) Compact (CPc) and diffuse (CPd) divisions of the central posterior nucleus. Ventromedial to CP is the anterior tuberal nucleus (AT) in the ventral hypothalamus. (<b>F</b>) Ventral tuberal nucleus (vT) of the anterior hypothalamus. (<b>G</b>) (inset) Dorsal view of midshipman brain with relative positions of A–F. <b>Abbreviations:</b> Cerebellum (C); Cerebral Aqueduct (CA); Horizontal commissure (HoC); Internal arcuate fiber tract (iaf); Fourth ventricle (IV); Lateral hypothalamus (LH); Midbrain (M); Magnocelluar octaval nucleus (MG); Olfactory bulb (OB); Medial nucleus preglomerulosus (PGm); Periaqueductal gray (PAG); Magnocellular preoptic nucleus (PMg); Posterior parvocellular preoptic nucleus (PPp); Paratoral tegmentum (PTT); Optic tectum (TeO); Ventral secondary octaval nucleus (SOv); Telencephalon (T); Molecular layer of the valvula (Vm). Scale Bars = 500 µm.</p

cFos response to social acoustic signals (advertisement calls) in hypothalamic vocal-acoustic circuitry.

<p>Representative images of cFos-ir neurons (red/pink) within the anterior tuberal nucleus (AT) (<b>A</b>,<b>B</b>) and ventral tuberal nucleus (vT) (<b>D</b>,<b>E</b>) of males who were exposed to social acoustic signals versus males exposed to ambient environmental noise. Data in <b>C</b> and <b>F</b> are represented as mean number of cFos-ir neurons per section ± SE, **<i>p</i> = 0.01. Scale bar = 100 µm. Arrows represent the dorsal (D) and lateral (L) orientation for each image.</p

cFos response to social acoustic signals (advertisement calls) in the ascending auditory pathway.

<p>Representative images of cFos-ir neurons (red/pink) within males who were exposed to social acoustic signals (left column, A, C, E) versus males who were exposed to ambient environmental noise (right column, B, D, F). (<b>A</b>,<b>B</b>) Rostral intermediate division of the descending octaval nucleus (DOri) within the medulla. (<b>C</b>,<b>D</b>) The periventricular nucleus centralis within the midbrain torus semicircularis (TSnc). (<b>E</b>,<b>F</b>) Compact division of the central posterior nucleus (CP) in the auditory thalamus. Scale bar = 100 µm. Arrows represent the dorsal (D) and lateral (L) orientation for each image. Data in <b>G</b>–<b>I</b> are represented as mean number of cFos-ir neurons per section ± SE, *<i>p</i><0.05 **<i>p</i>≤0.01, ***<i>p</i><0.001.</p