Anatomical and electrophysiological comparison of the sensory innervation of bronchial and tracheal parasympathetic ganglion neurons
Abstract
Anatomical and electrophysiological techniques were used to examine differences in the level of sensory nerve terminals localized in parasympathetic ganglia in guinea pig trachea and bronchus. We quantified substance-P-immunoreactive nerve terminal profiles within the ganglia and the amplitude of capsaicin-sensitive depolarization (slow excitatory postsynaptic potential or sEPSP) evoked by vagus (bronchial) or recurrent (tracheal) nerve-stimulation. Substance-P-immunoreactive axon profiles per intrinsic tracheal neuron were fewer in number than per bronchial ganglion neuron. The average amplitude and duration of the capsaicin-sensitive sEPSPs were similar in tracheal and bronchial ganglion neurons. Furthermore, capsaicin evoked a nearly equal depolarization of bronchial and tracheal ganglion neurons. The sEPSPs were reduced in both areas by a selective neurokinin-3 receptor antagonist. SR142801. These results demonstrate that although the number of sensory nerve fibers in tracheal ganglia are significantly less than those in the bronchus, this did not translate to an obvious physiological difference in sEPSP amplitude.
References
Citations
Endogenous neurokinins facilitate synaptic transmission in guinea pig airway parasympathetic ganglia
Substance P modulates nicotinic responses of intracardiac neurons to acetylcholine in the guinea pig
Effect of bradykinin on membrane properties of guinea pig bronchial parasympathetic ganglion neurons
Related Concepts
Related Feeds
Antibody Specificity
Antibodies produced by B cells are highly specific for antigen as a result of random gene recombination and somatic hypermutation and affinity maturation. As the main effector of the humoral immune system, antibodies can neutralize foreign cells. Find the latest research on antibody specificity here.
Barrel cortex
Here is the latest research on barrel cortex, a region of somatosensory and motor corticies in the brain, which are used by animals that rely on whiskers for world exploration.