Catecholaminergic neurons in medullary nuclei are among the post-synaptic targets of descending projections from infralimbic area 25 of the rat medial prefrontal cortex

Abstract

The medial prefrontal cortex (mPFC) is directly involved in the integration of cognitive and autonomic functions underlying flexible goal-directed behavior (Cechetto and Saper, 1990;Neafsey et al., 1993;Loewy, 1991;Owens et al., 1999;Van Eden and Buijs, 2000;Drevets, 2000;Heidbreder and Groenewegen, 2003). In the rat, the mPFC is composed of the anterior cingulate (ACd, Brodmann area 24b), prelimbic (PL, area 32), infralimbic (IL, area 25), and peduncular (P) cortices (Neafsey et al., 1993;Gabbott et al., 2005;Resstel and Corrêa, 2006b).Anatomical and physiological evidence indicates that areas of dorsal (d) mPFC (ACd and dPL cortices) process cognitive information, whereas regions of ventromedial prefrontal cortex (vmPFC) (vPL, IL and P cortices) are also involved in autonomic and visceral functions, especially, cardiovascular and respiratory activities (Hardy and Mack, 1990;Neafsey, 1990;Loewy, 1991;Neafsey et al., 1993;Spyer, 1994;Fisk and Wyss, 2000;Uylings et al., 2003;Heidbreder and Groenewegen, 2003). Descending efferent projections from vmPFC, in particular IL cortex, innervate a wide range of subcortical autonomic centers, including the nucleus tractus solitarius (NTS) and ventrolateral medulla (VLM), brain stem nuclei strategically involved in cardiopulmonary activities (Agarwal and Calarescu, 1992;Van Giersbergen et al., 1992;Dampney, 1994;Owens and Verberne, 1996, 2000Owens et al., 1999). Indeed, stimulation of the vPL and IL cortices is known to influence arterial blood pressure and blood flow through specific vascular beds (Owens and Verberne, 2001). As a result, the vmPFC has been considered to represent a 'visceromotor' territory of the rodent PFC (Terreberry and Neafsey, 1987;Ruit and Neafsey, 1990;Loewy, 1991;Neafsey et al., 1993; Resstel and Corrêa, 2006a,b).Although the pathways from IL cortex to autonomic centers in the brain stem have been described in previous light microscope studies (Sesack et al., 1989;Hurley et al., 1991;Takagishi and Chiba, 1991;Van Eden and Buijs, 2000;Heidbreder and Groenewegen, 2003;Vertes, 2004;Gabbott et al., 2005), the ultrastructural identities and neurochemical content of the post-synaptic target neurons have not been investigated in detail (Zagon et al., 1994;Torrealba and Müller, 1999). Of specific functional significance is that catecholaminergic neurons in the NTS and rostral ventrolateral medulla (rVLM) are strategically in-*Correspondence to: P. L. A. Gabbott, Department of Biological Sciences, The Open University, Milton Keynes, MK7 6AA UK. Tel: ϩ44-1908-659469; fax: ϩ44-1908-654167. E-mail address: p.l.gabbott@open.ac.uk (P. L. A. Gabbott). Abbreviations: ACd, dorsal anterior cingulate cortex (area 24b); B, Bregma; BDA, biotinylated dextran amine; BLA, basolateral nucleus of the amygdala; CEA, central nucleus of the amygdala; DAB, 3,3=-diaminobenzidine; DMH, dorsomedial hypothalamic nucleus; DMX, dorsal motor nucleus of the vagus; IL, infralimbic cortex (area 25

Central neural responses to restraint stress are altered in rats with an early life history of repeated brief maternal separation

“…Labeling results from missed injections in our study confirmed this by producing little to no retrograde labeling within the PVN or other forebrain regions of interest when the FG injection site targeted structures situated dorsal (i.e., gracile or cuneate nuclei) or ventral (i.e., hypoglossal nucleus) to the mid-NST/DMV. Conversely, FG tracer injections centered within the mid-NST/DMV produced retrograde labeling in regions previously reported to project to the DVC (Gray and Magnuson, 1987, Danielsen et al, 1989, Rinaman, 2003b, Gabbott et al, 2007), including the mPFC (prelimbic and infralimbic cortices), CeA (primarily its lateral region), PVN (primarily its ventral parvicellular subdivision; see Fig. 8), and BNST (primarily its dorsolateral region; see Fig.…”

“…Tracer injection sites targeted the mid-NST/DMV and were intentionally large in order to maximize the amount of retrograde labeling achieved. Previous reports have demonstrated that the PVN, BNST, CeA, and mPFC provide little or no direct input to hindbrain regions immediately surrounding the DVC (Luiten et al, 1985, Saha et al, 2000, Dong et al, 2001, Gabbott et al, 2007). Labeling results from missed injections in our study confirmed this by producing little to no retrograde labeling within the PVN or other forebrain regions of interest when the FG injection site targeted structures situated dorsal (i.e., gracile or cuneate nuclei) or ventral (i.e., hypoglossal nucleus) to the mid-NST/DMV.…”

Hypothesis-driven structural connectivity analysis supports network over hierarchical model of brain architecture

“…Second, the viscerosensory nucleus of the solitary tract (NTS) projects directly to the behavioral state system (23,24), the PTA/PVTa, and the ILA (Fig. 2), the latter two of which are noradrenergic (25,26). Aside from the pharmacological evidence of a central noradrenergic influence on stress, depression, and appetite (27), this is interesting because the ILA projects directly to the NTS, providing the substrate for a possible very long cortico > NTS feedback loop (Fig.…”

Dorsal vs. ventral differences in fast Up-state-associated oscillations in the medial prefrontal cortex of the urethane-anesthetized rat

“…In addition, each subregion has different inputs and outputs (Gabbott et al 2007; Hoover and Vertes 2007; Vertes et al 2015; Kuramoto et al 2016) and has different functional roles (Heidbreder and Groenewegen 2003; Kesner and Churchwell 2011; Vertes et al 2015). In particular, ACC and PrL play a role in attention and working memory, while the more ventral IL has been implicated in goal-directed behavior and autonomic functions (Miller and Cohen 2001; Heidbreder and Groenewegen 2003; Seamans et al 2008; Kesner and Churchwell 2011; Euston et al 2012; Parnaudeau et al 2013).…”