CNS cell groups involved in the control of the ischiocavernosus and bulbospongiosus muscles: A transneuronal tracing study using pseudorabies virus

Abstract

Transneuronal tracing techniques were used to identify spinal and brainstem neurons involved in the control of perineal muscles in the male rat. Two penile muscles, the bulbospongiosus and ischiocavernosus muscles, were injected with Bartha's strain of pseudorabies virus. After survival periods of 2, 4, and 5 days, the rats were killed and viral labeled neurons identified by immunohistochemistry. After a 2 day survival period, only pudendal motoneurons were labeled. More spinal and brainstem neurons were labeled at longer survival times. Putative spinal interneurons were found from T13 to S1. Large numbers of neurons were found in the lateral horn of the T13-L2 and L6-S1 segments which contain sympathetic and parasympathetic preganglionic neurons, respectively. However, retrograde labeling experiments verified that very few of the viral neurons were preganglionic neurons. Other labeled neurons were found in the intermediate cord, especially around the central canal. Relatively few labeled neurons were seen in the dorsal or ventral horn. In the brainstem, consistent labeling was seen in the ventrolateral medulla, raphe pallidus, and magnus, the A5 and locus ceruleus noradrenergic cell groups. Barrington's nucleus in the pontine tegmentum, the periaqueductal gray, and the paraventricular nucleus of the hypothalamus. The transneuronal labeling was consistent with what is currently known of the central nervous system (CNS) control of the perineal muscles.

Distinct patterns of neuronal inputs and outputs of the juxtaparaventricular and suprafornical regions of the lateral hypothalamic area in the male rat

“…In addition to a well established role in the control of micturition (Marson, 1997; Valentino et al, 2000), it is increasingly apparent that Barrington's nucleus is also implicated in far more diverse aspects of autonomic and behavioral control (Cano et al, 2000; Sved et al, 2002). Recent transneuronal tracing studies suggest the existence of multisynaptic projections from Barrington's nucleus to several organs and tissues besides the bladder, these include: the trachea (Haxhiu et al, 1993), kidney (Cano et al, 2000), spleen (Cano et al, 2000; Cano et al, 2001), pancreas (Loewy and Haxhiu, 1993), distal colon (Valentino et al, 2000), gonads (Marson et al, 1993; Marson, 1995; Marson and McKenna, 1996; Orr and Marson, 1998; Papka et al, 1998; Tang et al, 1999; Marson and Murphy, 2006), and brown adipose tissue (Cano et al, 2003). Furthermore, Barrington's nucleus is activated by a variety of stressors (Sved et al, 2002).…”

Serotonergic lesions of the periaqueductal gray, a primary source of serotonin to the nucleus paragigantocellularis, facilitate sexual behavior in male rats

“…The nPGi receives projections from upstream sites related to sexual behavior, including the paraventricular nucleus of the hypothalamus, medial preoptic area, and periaqueductal gray (Murphy and Hoffman, 2001; Murphy et al, 1999; Normandin and Murphy, 2008), and in turn, projects to the spinal motoneurons (pudendal motoneurons) innervating the bulbospongiosus and ischiocavernosus muscles (Hermann et al, 2003; Marson and Carson 3rd, 1999; Marson and McKenna, 1996; Tang et al, 1999), which are critical for ejaculation in male rats (Miura et al, 2001; Pescatori et al, 1993) and humans (Hsu et al, 2004; Shafik et al, 2009). …”

Pseudorabies virus tracing of neural pathways between the uterine cervix and CNS: Effects of survival time, estrogen treatment, rhizotomy, and pelvic nerve transection

“…For these studies, we used the transneuronal tracer, pseudorabies virus (PRV). Previously, PRV has been used (for reviews, see Ugolini, 1992;Nauwynck, 1997;Card, 1998;Loewy, 1998;Norgren and Lehman, 1998) to identify the autonomic pathways of the adrenal gland (Strack et al, 1989), ovary (Gerendai et al, 1998), uterine horns (Papka et al, 1998), kidney (Schramm et al, 1993), bladder (Nadelhaft and Vera, 1995), penis (Marson and McKenna, 1996), clitoris (Marson, 1995), gastrocnemius muscle (Rotto-Percelay et al, 1992), prostate (Orr and Marson, 1998), and retinohypothalamic tract (Card et al, 1991;Moore et al, 1995). The advantages of PRV over other neuronal tracers are that it crosses synapses selectively, does not spread nonspecifically into adjacent neurons , and replicates to detectable levels in each successive infected neuron.…”