Localization and Chemical Coding of the Dorsal Motor Vagal Nucleus (DMX) Neurons Projecting to the Porcine Stomach Prepyloric Area in the Physiological State and After Stomach Partial Resection

Abstract

The aim of our study was to localize and define immunocytochemical characteristic of the dorsal motor nucleus of the vagus (DMX) neurons projecting to the porcine stomach prepyloric region in the physiological state and after gastric partial resection. To identify the stomach-projecting perikarya, the neuronal retrograde tracer--Fast Blue (FB) was injected into the studied region of control and resection group (RES). In the RES group, on 22nd day after FB injection, the partial resection of the stomach region previously injected with FB was performed. Sections were immunostained with ChAT, pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), galanin (GAL), substance P (SP), leu-enkephalin (LENK), and cocaine- and amphetamine-regulated transcript (CART). In the DMX of control and RES group, the stomach-projecting perikarya were found in the entire extent of the nucleus bilaterally. Within control animals, 30.08 ± 1.97 % of the gastric DMX perikarya expressed PACAP, while other substances were found only in the neuronal fibers. In the RES group DMX, PACAP was found in 45.58 ± 2.2 %, VIP in 28.83 ± 3.63 %, NOS in 21.22 ± 3.32 %, and GAL in 5.67 ± 1.49 % of the FB-labeled gastric perikarya. Our data implicate PACAP, VIP, NOS, and GAL as neuronal survival promoting substances and the CART-, LENK-, SP- NOS-, and GAL-immunoreactive processes in control of the gastric vagal neurons in the pig.

Prolonged Acetylsalicylic-Acid-Supplementation-Induced Gastritis Affects the Chemical Coding of the Stomach Innervating Vagal Efferent Neurons in the Porcine Dorsal Motor Vagal Nucleus (DMX)

“…As we reported recently, the FB-labeled perikarya were observed to be scattered throughout the whole extent of both left and right DMX (Gańko and Całka 2013). Although the highest concentration of the FB-positive cells was detected in the middle nuclear region, their number decreased gradually toward the rostral and caudal pools of DMX where only single-labeled somata were found.…”

“…Moreover, our former data (Gańko and Całka 2013) showed characteristic distribution pattern of substance P (SP), leu enkephalin (LENK), and cocaine- and amphetamine-regulated transcript (CART) immunoreactive (IR) fibers in the DMX, indicating involvement of those neurotransmitters/neuromodulators in modulation of various gastric functions mediated by vagus nerve (Spencer and Talman 1986; Yang and Tache 1997; Browning et al 2002; Okumura et al 2000; Smedh and Moran 2006). Some reports also pointed to the participation of SP, LENK, and CART in processes related to gastritis as well as neurogenic or chemically induced inflammation (Gyires et al 2001; Sipos et al 2006; Burliński 2012).…”

“…According to former reports, induction of the NOS expression accompanied axotomy (Całka et al 2004; Gańko and Całka 2013), as well as inflammatory bowel disease (Miampamba and Sharkey 1999) or cystitis (Callsen-Cencic and Mense 1997). Therefore, neurons upregulate NO production in reaction to both peripheral denervation and an inflammatory state of the innervated organ.…”

“…The dorsal motor nucleus of the vagus nerve provides extrinsic efferent parasympathetic innervation of the stomach (Yoshida et al 1989; Okumura and Namiki 1990; Siaud et al 1990; Gańko and Całka 2013) which is responsible for the regulation of gastric motility, blood flow, secretion, gastric mucosal protection, and ulcer formation (Tache and Yoneda 1993; Travagli et al 2003; Zhou et al 2008). Our previous research proved that peripheral transection of the vagal efferent processes at the level of gastric wall evoked induction of the pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), and galanin (GAL) expression in response to a traumatic neuronal injury of the stomach supplying DMX perikarya (Gańko and Całka 2013).…”

“…Our previous research proved that peripheral transection of the vagal efferent processes at the level of gastric wall evoked induction of the pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), and galanin (GAL) expression in response to a traumatic neuronal injury of the stomach supplying DMX perikarya (Gańko and Całka 2013). This phenomenon has been also reported in the porcine descending colon (Gonkowski et al 2010; Gonkowski and Całka 2012) where both axotomy and an inflammatory state stimulated expression of PACAP and GAL in the intestinal ganglia.…”