CRF-like immunoreactive system in the quail brain.

Nerve cells and fibres immunoreactive for synthetic ovine corticotropin releasing factor were shown to be present in several brain areas of the quail by use of immunocytochemical techniques. CRF-like immunoreactive cell bodies are mainly clustered in the hypothalamic paraventricular nucleus, in the telencephalic nucleus accumbens and in the mesencephalic periventricular grey. The external zone of the anterior median eminence contains a rich network of immunoreactive fibers. CRF-like immunopositive fibers are not restricted to circumventricular organs, but have been observed in several prosencephalic regions and in close proximity of large vasotocin-containing neurons in the supraoptic and paraventricular regions. These observations suggest that, in birds, CRF-like material might be not only involved in the hypothalamic control of anterior pituitary hormone secretion, but also in different functions likely related to neurotransmission or neuromodulation.