Efferent neural pathways of the lamina terminalis subserving osmoregulation

Studies in rats and sheep show that neurons in the CVOs of the lamina terminalis provide extensive neural input to the vasopressin-containing cells of the supraoptic nucleus. This input is both by direct pathways and via a synapse in the MnPO which also has projections to the vasopressin-containing cells of the SON. Neurons throughout the lamina terminalis (including possible osmoreceptors in the OVLT and subfornical organ) are activated by systematic hypertonicity. It is likely that in response to hypertonicity they signal the SON and PVN to release vasopressin and elsewhere to elicit other osmoregulatory responses such as thirst and the excretion of sodium.