Immunoreactivity (IR) to galanin (GAL) was detected in a wide range of peripheral autonomic neurons in the toad Bufo marinus. Forty percent of adrenergic nerve cell bodies in paravertebral sympathetic ganglia had GAL-IR in addition to neuropeptide Y (NPY)-IR. Some of these neurons projected to systemic arteries. GAL-IR was localized in parasympathetic neurons supplying the heart, lung, pulmonary artery, bladder, rectum and tongue. Eighty-two percent of intracardiac vagal nerve cell bodies had both GAL-IR and somatostatin (SOM)-IR. GAL-IR and SOM-IR were also co-localized in cholinergic post-ganglionic vagal neurons supplying the lung musculature and the pulmonary artery, and in neurons intrinsic to the bladder. Many postganglionic glossopharyngeal neurons in the tongue contained both GAL-IR and vasoactive intestinal peptide (VIP)-IR. Therefore, in Bufo marinus, a GAL-like peptide, in combination with other peptides or with adrenaline or acetylcholine, may be involved in neurotransmission in several different functional classes of autonomic neurons.
- Autonomic neuron
- Neuropeptide Y
- Perivascular axon
- Vasoactive intestinal peptide