Galanin-(1-16) modulates 5-HTIA receptors in the ventral limbic cortex of the rat

The aim of the present study was to evaluate whether galanin(1-16) of the r at and porcine type and rat galanin-(1-29) can modulate the 5-HTIA receptor s, using [H-3]8-OH-DPAT as a radioligand, in membrane preparations from the ventral limbic cortex of the rat. Galanin-(1-16) produced a concentration dependent increase in the Kd value of [H-3]8-OH-DPAT binding sites with a m aximal effect of similar to 61% at 30 nM without changing the B-max values. The galanin antagonist M35 blocked these effects. Rat galanin produced the same pattern of response but was less potent and effective. These results indicate the existence of a galanin receptor subtype in the ventral limbic cortex mainly recognizing N-terminal galanin fragments and capable of more strongly modulating 5-HTIA receptors than cloned galanin receptors. NeuroRe port 11:515-519 (C) 2000 Lippincott Williams & Wilkins.