Calbindin immunoreactivity of enteric neurons in the guinea-pig ileum

Abstract

Previous studies have identified Dogiel type II neurons with cell bodies in the myenteric plexus of guinea-pig ileum to be intrinsic primary afferent neurons. These neurons also have distinctive electrophysiological characteristics (they are AH neurons) and 82-84% are immunoreactive for calbindin. They are the only calbindin-immunoreactive neurons in the plexus. Neurons with analogous shape and electrophysiology are found in submucosal ganglia, but, with antibodies used in previous studies, they lack calbindin immunoreactivity. An antiserum that is more effective in revealing calbindin in the guinea-pig enteric nervous system has been reported recently. In the present work, we found that this antiserum reveals the same population that was previously identified in myenteric ganglia, and does not reveal any further population of myenteric nerve cells. In submucosal ganglia, 9-10% of nerve cells were calbindin immunoreactive with this antiserum. The submucosal neurons with calbindin immunoreactivity were also immunoreactive for choline acetyltransferase, but not for neuropeptide Y (NPY) or vasoactive intestinal peptide (VIP). Small calbindin-immunoreactive neurons (average profile 130 microm2) were calretinin immunoreactive, whereas the large calbindin-immunoreactive neurons (average profile 330 microm2) had tachykinin (substance P) immunoreactivity. Calbindin immunoreactivity was seen in about 50% of the calretinin neurons and 40% of the tachykinin-immunoreactive submucosal neurons. It is concluded that, in the guinea-pig ileum, only one class of myenteric neuron, the AH/Dogiel type II neuron, is calbindin immunoreactive, but, in the submucosal ganglia, calbindin immunoreactivity occurs in cholinergic, calretinin-immunoreactive, secretomotor/vasodilator neurons and AH/Dogiel type II neurons.

Localisation of cannabinoid CB1 receptor immunoreactivity in the guinea pig and rat myenteric plexus

“…This value closely agrees with published data (Costa et al, 1996;Li and Furness, 2000;Quinson et al, 2001). Because these are cholinergic neurons (Costa et al, 1996) and we have shown that nearly all cholinergic neurons express CB 1 receptors, it was not surprising to find that over 90% of calbindin-positive neurons were also labelled for CB 1 receptors.…”

Development of nerves expressing P2X3 receptors in the myenteric plexus of rat stomach

“…It is believed that calbindin is a marker for intrinsic primary afferent neurones in the guinea-pig ileum (Quinson et al 2001). In the guinea-pig ileum, P2X 3 receptors did not to coexpress with calbindin D-28 (Poole et al 2002;Van Nassauw et al 2002).…”

The distribution of purine P2X2 receptors in the guinea-pig enteric nervous system

“…Four classes of nerve cell bodies account for almost all neurons in the submucosal ganglia of the guinea-pig ileum (Furness et al 1984;Quinson et al 2001). These are: (1) Dogiel type II neurons, immunoreactive for choline acetyltransferase (ChAT), tachykinins and calbindin (about 10% of nerve cells), (2) neurons immunoreactive for calretinin and ChAT (about 15%), (3) neurons with VIP immunoreactivity (about 45%) and (4) neurons with both NPY and ChAT immunoreactivity (about 30%).…”