Somatostatin-like immunoreactivity is expressed in neural crest cultures

Embryonic neural crest cells give rise to many adult cell types, including some neurons that contain the neuroactive peptide somatostatin. The development of somatostatin-like immunoreactive cells has been investigated in quail neural crest cultures. Somatostatin-like immunoreactive cells were first detected in such cultures after 5 days in vitro by immunocytochemistry. The number of immunoreactive cells and the intensity of the immunoreactivity increased dramatically between 5 and 6 days in vitro. The immunoreactivity was present in a small subset of cells in the culture. It was seen in the perikaryon and cellular processes, but was absent from the nucleus. Immunoreactive cells with and without processes were observed. Somatostatin immunoreactivity was absent if the anti-somatostatin serum was preincubated in the presence of somatostatin. A sequential procedure for detecting catecholamine-containing cells histochemically followed by immunocytochemistry for somatostatin-like immunoreactivity showed that about 20% of the cells which contained catecholamines also contained somatostatin-like immunoreactivity. Greater than 90% of the somatostatin-containing cells in this analysis also contained catecholamines. Somatostatin-like immunoreactivity was also detected and quantitated by radioimmunoassay. The somatostatin-like immunoreactivity developed in vitro in medium that contained horse serum and chick embryo extract, but in the absence of other embryonic cell types such as notochord and somitic mesenchyme. These in vitro results together with prior in vivo data indicate that expression of somatostatin-like immunoreactivity is an early event in the development of some neural crest cells which also express adrenergic properties.