[Drinking behavior and c-fos expression induced by chemical or electrical stimulation of SFO in rat brain]
To compare the drinking behavior and c-fos expression induced by chemical or electrical stimulation of subfornical organ (SFO) in rat brain. L-glutamic acid microinjection and constant electrical current were used as chemical and electrical stimulation of SFO, respectively. The water intake over 1 h was recorded and Fos expression was examined immunohistochemically. A similar volume of water intake and Fos expression pattern were induced by both methods of stimulation of SFO. These include 11 forebrain areas (organum vasculosum of the lamina terminalis, median preoptic nucleus, hypothalamic paraventricular nucleus, supraoptic nucleus and lateral hypothalamic area, paraventricular nucleus, reuniens nucleus and central medial nucleus of thalamus, bed nucleus of the stria terminalis, perifornical dorsal area and substantia innominata) and 4 areas of hindbrain (area postrema, nucleus solitary tract, lateral parabrachial nucleus and dorsal raphe nucleus). The drinking behavior and Fos expression in brain induced by SFO stimulation are the results of activation of the neuronal bodies in SFO.