Neurotransmitter composition of neurons in the cranial cervical and celiac sympathetic ganglia in postnatal ontogenesis.

The neurotransmitter composition of neurons in the cranial cervical ganglion (CCG) and celiac ganglia (CG) in rats of different ages (neonatal, 10, 12, 30, and 60 days) was studied by immunohistochemical methods. The results showed that most neurons in these sympathetic ganglia contain tyrosine hydroxylase (TH). Most TH-positive neurons were also neuropeptide Y (NPY)-positive. In all ganglia, the proportions of neurons containing NPY increased from the moment of birth to the end of the first month of life. In the CG, NPY was present in a significantly greater proportion of neurons than in the CCG. Substance P, vasoactive intestinal peptide, and choline acetyltransferase were present in occasional neurons in the CCG and CG from birth. There was no change in the proportion of this type of neuron with age. Definitive establishment of the neurotransmitter composition in the sympathetic ganglia studied here occurred by the end of the first month of life.