Long-term GnRH-induced gonadotropin secretion in a novel hypothalamo-pituitary slice culture from tilapia brain

- Organotypic cultures prepared from hypothalamo-pituitary slices of tilapia, were developed.
- The organotypic cultures maintained the original cytoarchitecture of pituitary cells.
- Long-term continuous exposure to GnRH induced secretion of LH and FSH.
- The electrical membrane properties of anterior pituitary cells in organotypic slice cultures were studied.
- Pituitary cells occasionally exhibited spontaneous spikes and spikelets at rest.

Organotypic cultures, prepared from hypothalamo-pituitary slices of tilapia, were developed to enable long-term study of secretory cells in the pituitary of a teleost. Values of membrane potential at rest were similar to those recorded from acute slices, and cells presented similar spontaneous spikes and spikelets. Some cells also exhibited slow spontaneous oscillations in membrane potential, which may be network-driven. Long-term (6 days) continuous exposure to GnRH induced increases in LH and FSH secretion. FSH levels reached the highest levels after 24 h of exposure to GnRH, and the highest secretion of LH was observed in days 4 and 5 of the experiment. Since slices were viable for several weeks in culture, maintaining the original cytoarchitecture, electrical membrane properties and the ability to secrete hormones in response to exogenous GnRH, this technique is ideal for studying the mechanisms regulating cell-to-cell communication under conditions resembling the in vivo tissue organization.